Re: Convert speaker spikes from quadrupod to tripod
James Harris
> My speakers have four spikes beneath them which makes it a pain to
> move the speakers even slightly as the length of at least one spike
> has to be adjusted to make all four rest on/in the floor. (The floor
> is solid - maybe concrete - and not wood.)
> Anyone heard of a kit to convert four spikes to three? It would have
> to fit beneath the existing arrangement as I don't want to modify the
> speakers (which are Dynaudio Audience 62 floorstanders).
> I'm thinking of something like a heavy duty plate with four solid
> fittings above and three below. I suppose an alteration to the sound
> is inevitable but would avoid scrap the idea if it has too much
> effect.
> An alternative is to put paving slabs on top of the carpet beneath the
> speakers. They should be heavy enough to not move and also present a
> more uniform surface for the speakers though even that would not be
> perfect. The slight problem here is the slabs sold by the local stores
> are fairly lightweight.
> Any ideas?
Widening the net a little....
James
Jim Lesurf
<79ac76a0-a140-4b62...@k19g2000yqn.googlegroups.com>,
James
Harris <james.h...@googlemail.com> wrote:
> On 21 Aug, 11:32, James Harris <james.harri...@googlemail.com> wrote:
> > My speakers have four spikes beneath them which makes it a pain to
> > move the speakers even slightly as the length of at least one spike
> > has to be adjusted to make all four rest on/in the floor. (The floor
> > is solid - maybe concrete - and not wood.)
I'd agree that three spikes are rather more practical than four. But afraid
I don't know of any kits for the below.
> > I'm thinking of something like a heavy duty plate with four solid
> > fittings above and three below. I suppose an alteration to the sound
> > is inevitable but would avoid scrap the idea if it has too much effect.
> > An alternative is to put paving slabs on top of the carpet beneath the
> > speakers. They should be heavy enough to not move and also present a
> > more uniform surface for the speakers though even that would not be
> > perfect. The slight problem here is the slabs sold by the local stores
> > are fairly lightweight.
TBH I have my doubts about such 'slabs' under 'spikes' being of much use.
Have a look at http://www.audiomisc.co.uk/cones/speak.html to see why I
have doubts about that. You might be better with a layer of something
squidgy like 'Blu Tak' between speaker and a heavy slab. Or just don't
bother. I've missed the previous parts of the thread is this is the first
posting on this thread I've seen, so I wonder why you think the 'spikes'
are desirable at all...
> > Any ideas?
> Widening the net a little....
Open the window wider and.... :-)
Slainte,
Jim
--
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html
Laurence Payne
<james.h...@googlemail.com> wrote:
>> My speakers have four spikes beneath them which makes it a pain to
>> move the speakers even slightly as the length of at least one spike
>> has to be adjusted to make all four rest on/in the floor. (The floor
>> is solid - maybe concrete - and not wood.)
>
>
>> Anyone heard of a kit to convert four spikes to three? It would have
>> to fit beneath the existing arrangement as I don't want to modify the
>> speakers (which are Dynaudio Audience 62 floorstanders).
I don't understand spikes. Audiophiles talk about coupling and
arrange heavy lumps of stone to couple to. But then they minimise
that coupling by restricting it to three or four points!
Perhaps the spikes are merely so you CAN adjust the speaker to stand
level on a concrete floor?
My practical experience of large speakers - some much larger than
anything found in a domestic setup - is that they generally sound MUCH
better mounted at least a small distance away from any flat surface,
wall or floor.
GeoSynch
>> My speakers have four spikes beneath them which makes it a pain to
>> move the speakers even slightly as the length of at least one spike
>> has to be adjusted to make all four rest on/in the floor. (The floor
>> is solid - maybe concrete - and not wood.)
Why do you want to move them around so much? Take the spikes off, experiment
with positioning the speakers for a week or two. When you're satisfied they're
optimally placed, put the spikes back on and leave them on and be done with it.
Brian Gaff
them over.
Brian
--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email: bri...@blueyonder.co.uk
______________________________________________________________________________________________________________
"James Harris" <james.h...@googlemail.com> wrote in message
news:79ac76a0-a140-4b62...@k19g2000yqn.googlegroups.com...
Laurence Payne
<Bri...@blueyonder.co.uk> wrote:
>I think the reason for four was health and safety actually, harder to wobble
>them over.
By audiophile reasoning, would just ONE spike, perfectly balanced, be
the ideal? :-)
Keith G
"Brian Gaff" <Bri...@blueyonder.co.uk> wrote in message
news:dDukm.71388$OO7....@text.news.virginmedia.com...
>I think the reason for four was health and safety actually, harder to
>wobble them over.
Wobbling over has nothing to do with the number of points of support but is
to do with the geometric relationship between the various points of support
and the speaker's centre of mass/gravity/momentum - pick whichever takes yer
fancy....
Keith G
"Laurence Payne" <l...@laurencepayne.co.uk> wrote in message
news:n2u495ts1hbqkgtfu...@4ax.com...
What do you mean by 'audiophile'...???
Keith G
"James Harris" <james.h...@googlemail.com> wrote in message
news:79ac76a0-a140-4b62...@k19g2000yqn.googlegroups.com...
IIRC, WW Greener's formula was that the projectile to be fired from a rifle
should not exceed that of 1/96th of the rifle's total weight (mass?) -
whether a speaker would need coupling to a firm foundation would depend upon
its overall weight (mass?) I suspect....
Richard Lamont
> On 21 Aug, 11:32, James Harris <james.harri...@googlemail.com> wrote:
>
>> My speakers have four spikes beneath them which makes it a pain to
>> move the speakers even slightly as the length of at least one spike
>> has to be adjusted to make all four rest on/in the floor. (The floor
>> is solid - maybe concrete - and not wood.)
>
>> Anyone heard of a kit to convert four spikes to three? It would have
>> to fit beneath the existing arrangement as I don't want to modify the
>> speakers (which are Dynaudio Audience 62 floorstanders).
The sound is supposed to come in a straight line from the speaker,
through the air, to your lugholes. It is not supposed to go via some
random scenic route involving whatever your loudspeaker is parked on.
Therefore your speakers should not be mechanically coupled to anything.
They should be mechanically isolated. Spikes are audiophool nonsense.
What you need is a nice thick sheet of neoprene rubber instead. Then the
sound will come from your speakers and not from whichever bits of your
building happen to radiate the coupled vibration. If you have carpet and
underlay then the neoprene probably isn't necessary.
--
Richard Lamont http://www.lamont.me.uk/
<ric...@lamont.me.uk>
OpenPGP Key ID: 0xBD89BE41
Fingerprint: CE78 C285 1F97 0BDA 886D BA78 26D8 6C34 BD89 BE41
Dave Plowman (News)
Brian Gaff <Bri...@blueyonder.co.uk> wrote:
> I think the reason for four was health and safety actually, harder to
> wobble them over.
Wouldn't they be banned totally, then, since they're more likely to make a
floor speaker topple than without? ;-)
--
*Don't worry; it only seems kinky the first time.*
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Laurence Payne
<k...@moirac.adsl24.co.uk> wrote:
>> By audiophile reasoning, would just ONE spike, perfectly balanced, be
>> the ideal? :-)
>
>
>
>What do you mean by 'audiophile'...???
The sort of reasoning that puts spikes on speakers but doesn't really
know why. Some say it's to "couple". Others to "decouple". What do
you think they're for?
Laurence Payne
<ric...@lamont.me.uk> wrote:
>What you need is a nice thick sheet of neoprene rubber instead. Then the
>sound will come from your speakers and not from whichever bits of your
>building happen to radiate the coupled vibration. If you have carpet and
>underlay then the neoprene probably isn't necessary.
What's the "speaker"? The drive unit? That plus the box it's in?
That plus the room it's in?
Keith G
"Richard Lamont" <ric...@lamont.me.uk> wrote
> The sound is supposed to come in a straight line from the speaker,
> through the air, to your lugholes. It is not supposed to go via some
> random scenic route involving whatever your loudspeaker is parked on.
>
> Therefore your speakers should not be mechanically coupled to anything.
> They should be mechanically isolated. Spikes are audiophool nonsense.
>
> What you need is a nice thick sheet of neoprene rubber instead. Then the
> sound will come from your speakers and not from whichever bits of your
> building happen to radiate the coupled vibration. If you have carpet and
> underlay then the neoprene probably isn't necessary.
I think you are missing the point entirely - the purpose of the spikes on
speakers it to enable them to be pushed through a carpet or any other
squidgy floorcovering (like you are recommending) to enable the speaker to
be coupled directly to the floor underneath and remove/reduce the ability of
the speaker to move in reaction (recoil) to the cone movements which some
claim 'blurs/renders less accurate' the created sound.
The usual comment is 'tighten up the bass' (treble not affected) and I
wouldn't argue with it, but I think the speaker's mass has a lot to do with
it irrespective of the floorcovering and is why I posted my comment about WW
Greener's formula....
Paul P
> The sound is supposed to come in a straight line from the speaker,
> through the air, to your lugholes. It is not supposed to go via some
> random scenic route involving whatever your loudspeaker is parked on.
Agreed.
> Therefore your speakers should not be mechanically coupled to anything.
> They should be mechanically isolated. Spikes are audiophool nonsense.
As I understand things, mechanical isolation is exactly what spikes
do. Maybe they can transmit some high frequencies but I don't see
them able to transmit low frequencies since the point of the cone
would have to vibrate at those frequencies. If the point is on
something rigid, like a slab of something, it's not going to move
much.
> What you need is a nice thick sheet of neoprene rubber instead. Then the
> sound will come from your speakers and not from whichever bits of your
> building happen to radiate the coupled vibration. If you have carpet and
> underlay then the neoprene probably isn't necessary.
I can see low frequencies moving quite easily through neoprene and
carpet.
Paul P
Keith G
> On Mon, 24 Aug 2009 12:57:11 +0100, "Keith G"
> <k...@moirac.adsl24.co.uk> wrote:
>
>>> By audiophile reasoning, would just ONE spike, perfectly balanced, be
>>> the ideal? :-)
>>
>>
>>
>>What do you mean by 'audiophile'...???
>
> The sort of reasoning that puts spikes on speakers but doesn't really
> know why.
OK, not what I understand the word to mean....
Some say it's to "couple". Others to "decouple". What do
> you think they're for?
Couple, of course - what would be the point of 'decoupling' unless you were
talking about a record deck and one lived directly over the Underground...??
Richard Lamont
>
> "Richard Lamont" <ric...@lamont.me.uk> wrote
>
>
>> The sound is supposed to come in a straight line from the speaker,
>> through the air, to your lugholes. It is not supposed to go via some
>> random scenic route involving whatever your loudspeaker is parked on.
>>
>> Therefore your speakers should not be mechanically coupled to anything.
>> They should be mechanically isolated. Spikes are audiophool nonsense.
>>
>> What you need is a nice thick sheet of neoprene rubber instead. Then the
>> sound will come from your speakers and not from whichever bits of your
>> building happen to radiate the coupled vibration. If you have carpet and
>> underlay then the neoprene probably isn't necessary.
>
> I think you are missing the point entirely - the purpose of the spikes
> on speakers it to enable them to be pushed through a carpet or any other
> squidgy floorcovering (like you are recommending) to enable the speaker
> to be coupled directly to the floor underneath and remove/reduce the
> ability of the speaker to move in reaction (recoil) to the cone
> movements which some claim 'blurs/renders less accurate' the created sound.
As the mass of the cone is so much less than the mass of the speaker
cabinet as a whole, this is surely idiotic. Besides, any such reaction
will also occur during manufacturer's testing and will therefore be
taken into account at the design stage.
Richard Lamont
The box, obviously.
Richard Lamont
> As I understand things, mechanical isolation is exactly what spikes
> do. Maybe they can transmit some high frequencies but I don't see
> them able to transmit low frequencies since the point of the cone
> would have to vibrate at those frequencies. If the point is on
> something rigid, like a slab of something, it's not going to move
> much.
Rigid materials provide mechanical coupling. I don't understand how
being pointy would make any difference. Squidgy materials have 'give'
that attenuates the coupling.
It's a basic matter of mechanical engineering, not unique to audio.
Every anti-vibration device I've seen involved things like rubber and
maybe springs, but never spikes.
>> What you need is a nice thick sheet of neoprene rubber instead. Then the
>> sound will come from your speakers and not from whichever bits of your
>> building happen to radiate the coupled vibration. If you have carpet and
>> underlay then the neoprene probably isn't necessary.
>
> I can see low frequencies moving quite easily through neoprene and
> carpet.
But not as easily as through a rigid object, whatever its shape.
Laurence Payne
One person thinks spikes couple. Another thinks they decouple.
Someone else wants to consider the box containing the drivers (the
"speaker") separately from the room it's heard in.
Some would put a record deck on an absorbent mat. Some on wooden
cones then on a glass shelf then on more cones, or maybe spikes. But
I think they'd all leave the deck's suspended sub-chassis alone?
Audiophle logic.
Keith G
"Richard Lamont" <ric...@lamont.me.uk> wrote in message
news:h6u57k$ojo$1...@news.eternal-september.org...
You snipped the best bit:
"The usual comment is 'tighten up the bass' (treble not affected) and I
wouldn't argue with it, but I think the speaker's mass has a lot to do with
it irrespective of the floorcovering and is why I posted my comment about WW
Greener's formula...."
Note the 'I wouldn't argue with it' bit!
Try it yourself is all I can say - and post the results here.
FWIW, I have 6 pairs of speakers on the go here and only one of them is
spiked - and that pair is on stands which are filled with lead shot and
which have spikes through to the concrete floor (three of them each -
triangular). Here's a quick snap:
http://www.moirac.adsl24.co.uk/showntell/Triangular.jpg
(I have still not yet got round to sticking the speakers down with Blu Tack
after some six months!! :-)
Richard Lamont
In the context of the thread, in which the speaker was the thing being
put on spikes or a neoprene mat, clearly "speaker" referred to the box.
Clearly room acoustics and interaction between the room and the speaker
are important, but that doesn't justify conflating the terminology so
that "speaker" is defined as including the room.
GregS
>On Mon, 24 Aug 2009 01:34:32 -0700 (PDT), James Harris
><james.h...@googlemail.com> wrote:
>
>>> My speakers have four spikes beneath them which makes it a pain to
>>> move the speakers even slightly as the length of at least one spike
>>> has to be adjusted to make all four rest on/in the floor. (The floor
>>> is solid - maybe concrete - and not wood.)
>>
>>
>>> Anyone heard of a kit to convert four spikes to three? It would have
>>> to fit beneath the existing arrangement as I don't want to modify the
>>> speakers (which are Dynaudio Audience 62 floorstanders).
>
>I don't understand spikes. Audiophiles talk about coupling and
>arrange heavy lumps of stone to couple to. But then they minimise
>that coupling by restricting it to three or four points!
I first heard of spikes and it had solid reasoning as used on rugs on wood floors.
For cement, you need another medium to convert, like using a piece
of soft pine under each spike on top of the cement. The spike will auto level,
and provide a better impedance match of the mechanical system
That would not work either for some speakers at loud volume, and the speaker
will start to walk. Some rubber would healp that scenereo.
greg
Dave Plowman (News)
Laurence Payne <l...@laurencepayne.co.uk> wrote:
> Some would put a record deck on an absorbent mat. Some on wooden
> cones then on a glass shelf then on more cones, or maybe spikes. But
> I think they'd all leave the deck's suspended sub-chassis alone?
Garrard 301, etc, had no suspension and some mounted them in concrete. ;-)
--
*Arkansas State Motto: Don't Ask, Don't Tell, Don't Laugh.
Scott Dorsey
You can do either... you can couple the speaker to a huge mass, or you can
decouple it from all (possibly resonant) masses. Either method works, and
you can measure whether it's working or not (or you can just put your hand
on the floor and feel if it's vibrating).
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Laurence Payne
>>The sort of reasoning that puts spikes on speakers but doesn't really
>>know why. Some say it's to "couple". Others to "decouple". What do
>>you think they're for?
>
>You can do either... you can couple the speaker to a huge mass, or you can
>decouple it from all (possibly resonant) masses. Either method works, and
>you can measure whether it's working or not (or you can just put your hand
>on the floor and feel if it's vibrating).
Reading at face value, that reply states that spikes either couple or
decouple the speaker from what it's standing on. Depending on which
you WANTED them to do.
This can't be right. What DID you mean?
GregS
Another thing, if the floor is vibrating from the air vibrations, and
the speaker is still, the floor will make the speaker shake.
greg
GregS
Another thought, when the floor is vibrating, its likely not
to be in phase with the speaker output, and it will be frequency dependant.
At least this tend to stabilize the frequency slewing.
What am I talking about?? !!
greg
David Looser
>
> My practical experience of large speakers - some much larger than
> anything found in a domestic setup - is that they generally sound MUCH
> better mounted at least a small distance away from any flat surface,
> wall or floor.
At one time there was a fad for mounting speakers as far into room corners
as possible. My granddad, who was something of a "HiFi" enthusiast in the
1950s built a speaker cabinet which used the walls and floor as part of the
cabinet. I seem to remember that a barrow-load of sand was part of it as
well.
David.
Laurence Payne
<david....@btinternet.com> wrote:
>
>At one time there was a fad for mounting speakers as far into room corners
>as possible. My granddad, who was something of a "HiFi" enthusiast in the
>1950s built a speaker cabinet which used the walls and floor as part of the
>cabinet. I seem to remember that a barrow-load of sand was part of it as
>well.
Yup. And it probably got very loud with only a few watts input. If
we were prepared to let our speakers take up rather more space,
speaker design (and amp. power) could be very different :-)
Peter Larsen
>> Any ideas?
> Widening the net a little....
Spikes is a concept that seems woefully short of merit, while vibration
absorbers is known and described in the literature as efficient in terms of
reducing midrange coloration via secondary radiation from the floor.
Literature reference: accellerometer measuments made by Arne E. Jensen on
his 4433 and the floor they were located on and published in the danish
magazine High Fidelity around 1978 or so.
Poul Ladegaard took this a step further by demonstrating the additional
advantage in decoupling the (midrange) loudspeaker unit from the front
panel.
It would be most interestering if the spikists have similar accellorometer
measurements that document the advantage of spikes.
> James
Kind regards
Peter Larsen
Scott Dorsey
It depends on what you do with the spikes and where you place them. The
original intention was to couple the speaker through a carpet to a solid
floor, so the floor and the speaker move as a system. But they can also be
used with a flexible material like a rubber pad to decouple the speakers from
the floor.
Scott Dorsey
>Another thing, if the floor is vibrating from the air vibrations, and
>the speaker is still, the floor will make the speaker shake.
Yes.
But if the floor is vibrating from the air vibrations, you have a more
serious problem than that. A common one, but serious nevertheless.
Laurence Payne
>>Reading at face value, that reply states that spikes either couple or
>>decouple the speaker from what it's standing on. Depending on which
>>you WANTED them to do.
>>
>>This can't be right. What DID you mean?
>
>It depends on what you do with the spikes and where you place them. The
>original intention was to couple the speaker through a carpet to a solid
>floor, so the floor and the speaker move as a system. But they can also be
>used with a flexible material like a rubber pad to decouple the speakers from
>the floor.
In the second case, why spikes? Why not just the rubber pad?
Scott Dorsey
>"Laurence Payne" <l...@laurencepayne.co.uk> wrote in message
>>
>> anything found in a domestic setup - is that they generally sound MUCH
>> better mounted at least a small distance away from any flat surface,
>> wall or floor.
>
>At one time there was a fad for mounting speakers as far into room corners
>as possible. My granddad, who was something of a "HiFi" enthusiast in the
>1950s built a speaker cabinet which used the walls and floor as part of the
>cabinet. I seem to remember that a barrow-load of sand was part of it as
>well.
The corner horn had some advantages: first of all it meant that you could
take advantage of the edge effects of the corner to provide increased bass
response, and secondly that bass boost was predictable because everyone would
put the speaker in the same place in every room, rather than have it an
unknown distance from the rear and side walls.
It made sense back in the fifties when loaded horns were essential for high
efficiency at low frequencies, in an era of low amplifier power. Back then,
systems were mono and so the inability to place the speaker for good imaging
was a non-issue.
When stereo came in, corner horns went away.
Scott Dorsey
You want to minimize the area of contact with the pad. Plenty of more
efficient ways to do that than spikes, mind you, but spikes are usually
what people have handy.
David Looser
news:h6ufn2$hj2$1...@panix2.panix.com...
It wasn't a horn, it was a bass-reflex.
David.
Scott Dorsey
>>
>> When stereo came in, corner horns went away.
>
>It wasn't a horn, it was a bass-reflex.
There's a lot less benefit in putting a bass-reflex design in a corner,
but you do still get that edge effect and the matter of consistency.
David Looser
> David Looser <david....@btinternet.com> wrote:
>>>
>>> When stereo came in, corner horns went away.
>>
>>It wasn't a horn, it was a bass-reflex.
>
> There's a lot less benefit in putting a bass-reflex design in a corner,
> but you do still get that edge effect and the matter of consistency.
I don't buy this "consistency" notion. There are still far too many
diferences: room size, furnishings and building construction. And that's
before we think about differences in the speakers themselves: driver types
and sizes, materials used, construction techniques etc.
David.
Paul P
> Laurence Payne <l...@laurencepayne.co.uk> wrote:
>>In the second case, why spikes? Why not just the rubber pad?
> You want to minimize the area of contact with the pad. Plenty of more
> efficient ways to do that than spikes, mind you, but spikes are usually
> what people have handy.
I've thought that the minimal contact area was important but the
smaller you go the higher the pressure so do things remain the
same ?
Paul P
Richard Crowley
> "Scott Dorsey" wrote...
>> When stereo came in, corner horns went away.
>
> It wasn't a horn, it was a bass-reflex.
If you had ever seen one, you would know better.
Paul Klipsch was (is?) famous for his corner horns.
"The Klipschorn is the only speaker in the world that has been
in continuous production, relatively unchanged, for over 60 years."
http://en.wikipedia.org/wiki/Paul_W_Klipsch
But the most impressive corner horn demo I saw was the Cerwin-
Vega room at an AES convention in LA in the 1970s. They had
an "M" cabinet which looked like a largish column speaker. But
when positioned just right facing into the corner, it would flap your
pants legs at 20 ft. This page has a drawing of the appliation...
http://www.in70mm.com/news/2007/sensurround/clearance/index.htm
at the bottom of the page.
C-W were also showing a 12-inch(?) driver which they would
plug directly into the 120V power mains outlet in the hotel room.
There were rumors that C-W cracked some plaster and had to
pay the hotel for repairs. And other rumors that the JBL demos
in another room down the hall, were reproducing such realistic
gunshot sounds (thanks to their 075 ring radiator tweeters, aka.
the "acoustic laser") that the LAPD was called out to investigate.
Richard Crowley
> "Laurence Payne"wrote ...
>> "Brian Gaff"wrote:
>>>I think the reason for four was health and safety actually, harder to
>>>wobble them over.
>>
>> By audiophile reasoning, would just ONE spike, perfectly balanced, be
>> the ideal? :-)
>
> What do you mean by 'audiophile'...???
Perhaps he misspelled "audiophool".
Peter Larsen
> David Looser <david....@btinternet.com> wrote:
>>> When stereo came in, corner horns went away.
>> It wasn't a horn, it was a bass-reflex.
> There's a lot less benefit in putting a bass-reflex design in a
> corner, but you do still get that edge effect and the matter of
> consistency.
Ime it is about the same 8 dB and they are worth having because the boost
from a corner is the smoothest available, also it fits a traditional tone
control very well and it is easy to get some degree of perceived
linearisation. With my current 4 way it is just a matter of overall bass
unit(s) drive level to get a reasonable tonal balance.
--scott
Kind regards
Peter Larsen
Richard Crowley
> Reading at face value, that reply states that spikes either couple or
> decouple the speaker from what it's standing on. Depending on which
> you WANTED them to do.
>
> This can't be right. What DID you mean?
Like many audiophool gimmics, it does what you *want* it to do.
It doesn't have to abide by the laws of physics (or economics or
common sense). That's the beauty of it.
David Looser
news:7fg2b9F...@mid.individual.net...
> "David Looser" wrote ...
>> "Scott Dorsey" wrote...
>>> When stereo came in, corner horns went away.
>>
>> It wasn't a horn, it was a bass-reflex.
>
> If you had ever seen one, you would know better.
>
Did you bother to read the thread before posting that response? I thought
not.
I did see the corner speaker *I'm* talking about, which is more than you
have. And it was a bass-reflex.
David.
Ian Iveson
>> My speakers have four spikes beneath them which makes it
>> a pain to
>> move the speakers even slightly as the length of at least
>> one spike
>> has to be adjusted to make all four rest on/in the floor.
>> (The floor
>> is solid - maybe concrete - and not wood.)
>
>
>> Anyone heard of a kit to convert four spikes to three? It
>> would have
>> to fit beneath the existing arrangement as I don't want
>> to modify the
>> speakers (which are Dynaudio Audience 62 floorstanders).
>
>
>> I'm thinking of something like a heavy duty plate with
>> four solid
>> fittings above and three below. I suppose an alteration
>> to the sound
>> is inevitable but would avoid scrap the idea if it has
>> too much
>> effect.
>
>
>> An alternative is to put paving slabs on top of the
>> carpet beneath the
>> speakers. They should be heavy enough to not move and
>> also present a
>> more uniform surface for the speakers though even that
>> would not be
>> perfect. The slight problem here is the slabs sold by the
>> local stores
>> are fairly lightweight.
Why don't chairs have three legs?
Tractors had three legs and they fell over easily. Maybe
they still do.
If you must use a tripod, put the single leg at the back,
otherwise the speaker will tip over if you brake mid-corner.
You can race a Morgan, but not a Reliant, unless you're
daft. At least when it falls over the chances are that it'll
be driver-side up, so a cone won't get spiked by the corner
of the coffee table.
If you had a four-to-three adaptor platform, then every time
you moved a speaker, you would need to lift it off its
platform, then move the platform, then lift the speaker back
onto it. That would surely take just as much time and effort
as adjusting a leg?
A flat stone could be more or less wobbly than four
imperfectly adjusted legs unless it's a lot wider, in which
case it might still be a bit wobbly and someone's bound to
trip and/or stub a toe on it, to boot, especially if you
keep moving it around. Anyway, if it's big and heavy then
it's hard to move, so how's that easier than adjusting a leg
or two?
If your floor is lumpy and you use a tripod, the chances are
that your speakers won't be upright.
You should put up with the need for adjustment.
Manufacturers of speakers (and cars) have generally found
the best compromise.
OTOH, perhaps an adaptor platform would make a plausible
audiophool accessory?
Ian
Scott Dorsey
>>>>
>>>> When stereo came in, corner horns went away.
>>>
>>>It wasn't a horn, it was a bass-reflex.
>>
>> There's a lot less benefit in putting a bass-reflex design in a corner,
>> but you do still get that edge effect and the matter of consistency.
>
>I don't buy this "consistency" notion. There are still far too many
>diferences: room size, furnishings and building construction. And that's
>before we think about differences in the speakers themselves: driver types
>and sizes, materials used, construction techniques etc.
Yup, that's true, but the number one thing that determines the low end
response (outside of the loudspeaker itself) is the boundary effect.
The corner horn controls that.
Now, things like standing waves in the room are still very, very significant
and corner placement doesn't do anything to reduce that; if anything it can
actually make some modes worse.
Peter Larsen
> C-W were also showing a 12-inch(?) driver which they would
> plug directly into the 120V power mains outlet in the hotel room.
Julian Hirsch tested it for stereo review, "the only result was a very loud
noise, no harm to the speaker"
> There were rumors that C-W cracked some plaster and had to
> pay the hotel for repairs. And other rumors that the JBL demos
> in another room down the hall, were reproducing such realistic
> gunshot sounds (thanks to their 075 ring radiator tweeters, aka.
> the "acoustic laser") that the LAPD was called out to investigate.
Kind regards
Peter Larsen
Scott Dorsey
>Richard Crowley wrote:
>
>> C-W were also showing a 12-inch(?) driver which they would
>> plug directly into the 120V power mains outlet in the hotel room.
>
>Julian Hirsch tested it for stereo review, "the only result was a very loud
>noise, no harm to the speaker"
Was any of that noise actually at 60 Hz, though, or was it all 120, 180, etc.?
>> There were rumors that C-W cracked some plaster and had to
>> pay the hotel for repairs. And other rumors that the JBL demos
>> in another room down the hall, were reproducing such realistic
>> gunshot sounds (thanks to their 075 ring radiator tweeters, aka.
>> the "acoustic laser") that the LAPD was called out to investigate.
I recall an incident with a falling chandelier in the Ritz-Carlton some time
around then....
GregS
OK, near the end of Speaker Builder magazine, and in Audio Express, a fellow was putting ports
or "bass reflex" into his horns to get improved performance.
So it might be either or both.
greg
Peter Larsen
> Peter Larsen <dig...@hotmail.com> wrote:
>> Richard Crowley wrote:
>>> C-W were also showing a 12-inch(?) driver which they would
>>> plug directly into the 120V power mains outlet in the hotel room.
>> Julian Hirsch tested it for stereo review, "the only result was a
>> very loud noise, no harm to the speaker"
> Was any of that noise actually at 60 Hz, though, or was it all 120,
> 180, etc.?
This is something I read in a borrowed magazine in 1978-ish - do not expect
too much detail, what he tested was whether the subwoofer in question would
survive being connected to a 115 volt outlet as claimed and so it did.
Kind regards
Peter Larsen
Eiron
> Richard Crowley wrote:
>
>> C-W were also showing a 12-inch(?) driver which they would
>> plug directly into the 120V power mains outlet in the hotel room.
>
> Julian Hirsch tested it for stereo review, "the only result was a very loud
> noise, no harm to the speaker"
I heard that Bose fitted a light bulb in series with the drivers
(inside the cabinet) to protect them, and to allow the 'mains demo'.
Don't know how true it is though.
--
Eiron.
Arny Krueger
> C-W were also showing a 12-inch(?) driver which they would
> plug directly into the 120V power mains outlet in the
> hotel room.
> There were rumors that C-W cracked some plaster and had to
> pay the hotel for repairs.
I believe that there are a number of extant modern woofers that can survive
this treatment for at least a little while without tricks. 120 volts is the
same as 1,800 watts into 8 ohms, which is not an unbelievable amount of
power by modern standards.
On the tricks side, a woofer with a 60.0 Hz resonance would not absorb
*that* much power, given that its impedance at 60 Hz might be as high as 30
ohms or more, and only 4 amps (480 watts) or less would need to be
dissipated in the voice coil.
Also, a woofer with a 16 ohm voice could would need to absorb *only* 900
watts. A mere pittance! ;-)
Arny Krueger
I've ever heard spike claimed to be the mechanical equivalent of diodes...
...but audiophools say a lot of crazy things.
Driver moving mass is usually much less than 100 grams, but can be a 400
grams for some low-efficiency subwoofers. If the woofer is attached to a
substantial cabinet, the actual motion of the speaker enclosure due to cone
motion will be highly damped by simple mass loading to the point where the
energy thus radiated is trivial.
In general, the vibrations radiated by the cone are by far the most
important effect of the speaker, which is according to the basic design. ;-)
The proof of the pudding is to suspend the speaker in the almost same
location by means of fishline suspended from the ceiling which gives a very
strong decoupling effect. In actual tests, the speaker sounds the same.
Don Pearce
wrote:
Mmmm.... Don't try it over here in England.
d
Richard Crowley
> "Richard Crowley" wrote ...
>> "David Looser" wrote ...
>>> "Scott Dorsey" wrote...
>>>> When stereo came in, corner horns went away.
>>>
>>> It wasn't a horn, it was a bass-reflex.
>>
>> If you had ever seen one, you would know better.
>>
>
> Did you bother to read the thread before posting that response? I
> thought not.
I did read the thread. It appears to be talking about the classic
Klipsch corner. You can go back and review it if you're confused.
> I did see the corner speaker *I'm* talking about, which is more than
> you have. And it was a bass-reflex.
I guess we don't know which corner speaker *you're* talking about,
then.
Keith G
> On Mon, 24 Aug 2009 16:49:28 +0100, "David Looser"
> <david....@btinternet.com> wrote:
>
>>
>>At one time there was a fad for mounting speakers as far into room corners
>>as possible. My granddad, who was something of a "HiFi" enthusiast in the
>>1950s built a speaker cabinet which used the walls and floor as part of
>>the
>>cabinet. I seem to remember that a barrow-load of sand was part of it as
>>well.
>
> we were prepared to let our speakers take up rather more space,
> speaker design (and amp. power) could be very different :-)
Still is for a lot of people who prefer low power amp+efficient speakers to
*powerhouse* arcwelder+ironing board setups....
Scott Dorsey
The Bose 901 doesn't do the light-bulb trick (although it IS a cool trick
in some ways). However, if you do an impedance plot of the 901, you'll find
it's something like 120 ohms at 60 Hz.
This means if you actually plug it into a 120V line, you get P=V^2/R= 120
watts of power actually going into the speakers, which isn't enough to hurt
them.
That is, what you are demonstrating is mostly how inefficient the speakers
are at low frequencies.....
David Looser
news:h6upj9$9sn$1...@usenet01.srv.cis.pitt.edu...
I wonder why it is that people who have never seen the speaker I'm talking
about, indeed know nothing about it beyond what I've told them, still insist
on trying to tell me what it "might be"? This wasn't a horn with a port in
it, it was a bass-reflex, OK?
David.
David Looser
>
> I did read the thread. It appears to be talking about the classic
> Klipsch corner.
Actually the thread is about spikes, note the thread title. *One person*
misunderstood what I was talking about and mentioned corner horns. That
hardly makes this a thread about "the classic Klipsch corner".
> You can go back and review it if you're confused.
I'm not confused - you are. Clearly, contrary to your assertion above, you
did *not* read this thread before posting!
>
>> I did see the corner speaker *I'm* talking about, which is more than
>> you have. And it was a bass-reflex.
>
> I guess we don't know which corner speaker *you're* talking about,
> then.
No you don't, as I told you.
David.
Eiron
Maybe they thought you were talking generally about speakers in corners
rather than the specific one which your grandfather built.
--
Eiron.
Arny Krueger
news:4a92f6a4.1781369140@localhost
Yup - 230 volts, 50 Hz.
David Looser
> Maybe they thought you were talking generally about speakers in corners
> rather than the specific one which your grandfather built.
>
Scott replied as though corner speakers could only be horns, fair enough if
that's the only sorts he's met. I simply pointed out that the one I was
talking about was a bass-reflex. But then Richard Crowley crashed in with
"If you had ever seen one, you would know better", clearly indicating that
he had no idea what the point of my comment had been, or indeed on the flow
of thread up to that point. Then GregS comes in with "So it might be either
or both" when it is clear from the context that "it" is the speaker I was
talking about. Yes I get pissed-off when people tell me that I would "know
better" simply because they are incapable of following a thread!
David.
UnsteadyKen
says...
> Here's a quick snap:
>
> http://www.moirac.adsl24.co.uk/showntell/Triangular.jpg
I see we shared the same taste in upmarket equipment racks and
meticulous wiring practice.
UnsteadyKen
Peter Larsen
> Actually the thread is about spikes, note the thread title.
So it was, but then we all settled for chatting about something meaningful.
And if you wanna use three spikes then it really really had better be for a
corner box.
>> I guess we don't know which corner speaker *you're* talking about,
>> then.
> No you don't, as I told you.
Then stop playing your silly undefined variable game and tell us what
speakear it is about.
> David
Kind regards
Peter Larsen
Peter Larsen
> "Eiron" <E1...@hotmail.com> wrote>
>> Maybe they thought you were talking generally about speakers in
>> corners rather than the specific one which your grandfather built.
> Scott replied as though corner speakers could only be horns, fair
> enough if that's the only sorts he's met.
Actually it always was the case that there was only one other good technical
reason for a dedicated "corner only" design, and that other reason was to
save bricks and building time. Which is to say that the only "classic era"
corner bass reflex box known to me is the one designed by Briggs for a 12"
and I can't remember what else, probably a two-way.
> I simply pointed out that
> the one I was talking about was a bass-reflex. But then Richard
> Crowley crashed in with "If you had ever seen one, you would know
> better", clearly indicating that he had no idea what the point of my
> comment had been, or indeed on the flow of thread up to that point.
People here are really incompetent like and don't know that they are not
supposed to type comments into a thread between you and somebody else.
> Then GregS comes in with "So it might be either or both" when it is
> clear from the context that "it" is the speaker I was talking about.
> Yes I get pissed-off when people tell me that I would "know better"
> simply because they are incapable of following a thread!
This is because the good people here are not only technically incompetent,
they also do not have manners and they don't know the prior state of the
art. You should have seen this earlier on and understood that because of
their vast technnical ignorance they didn't know what corner box you were
speaking about and then you should have told them and provided a web link to
description and photos.
http://www.lansingheritage.org/images/jbl/specs/home-speakers/1954-hartsfield/page01.jpg
Is the one I'd like to have, way better midrange unit that the Klipsch box.
Meindert Sprang
news:C7KdnaKg4aUUjg7X...@bt.com...
>
>
> > ftp://unste...@ftp.btinternet.com/pub/mycrap.JPG
>
> oopths
>
> http://www.btinternet.com/~unsteadyken/mycrap.JPG
The brandname "IKEA" springs to mind....
Meindert
Dave Plowman (News)
Some judicious use of trunking wouldn't go amiss. ;-)
--
*How do they get the deer to cross at that yellow road sign?
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Laurence Payne
<dig...@hotmail.com> wrote:
>http://www.lansingheritage.org/images/jbl/specs/home-speakers/1954-hartsfield/page01.jpg
>
>Is the one I'd like to have, way better midrange unit that the Klipsch box.
I love the "Koustical lens" :-)
Laurence Payne
<m...@NOJUNKcustomORSPAMware.nl> wrote:
>> http://www.btinternet.com/~unsteadyken/mycrap.JPG
>
>The brandname "IKEA" springs to mind....
Actually, one of those cheap Ikea wooden shelving units could probably
do a neater job. And wood's always nicer to look at. Or are those
"magic" shelves?
Meindert Sprang
Yeah, probably plated with non-magnetostrictive chrome...
Meindert
UnsteadyKen
Dave Plowman (News) says...
> Some judicious use of trunking wouldn't go amiss. ;-)
I tried that and cable tidies and ending up pulling my hair out when I
changed anything.
It photographs worse than it looks, sort of. We have so many sources
now, bring back the good old days. Connect up the turntable, tuner and
cassette deck and wonder what on earth the Aux socket could be used for.
Now I have 4 switch boxes.
--
Ken O'Meara
http://www.btinternet.com/~unsteadyken/
UnsteadyKen
Laurence Payne says...
> Actually, one of those cheap Ikea wooden shelving units could probably
> do a neater job. And wood's always nicer to look at. Or are those
> "magic" shelves?
Ikea! Heavens man, do you think I've won the lottery?
Economy before neatness is my motto.
They are unbranded flat pack kitchen racks from my usual audiophile
supplier
http://www.tjmorris.co.uk/
"magic" for the price 12 quid each, sturdy, adjustable shelf spacing and
lightweight.
GregS
Hey, I got one of those. Its really nice. I had a 31 inch crt tv on it.
Heavy !!
greg
Powell
"James Harris" wrote
>> My speakers have four spikes beneath them which makes it a pain to
>> move the speakers even slightly as the length of at least one spike
>> has to be adjusted to make all four rest on/in the floor. (The floor
>> is solid - maybe concrete - and not wood.)
>
"concrete"... is a very good vibration sink compared to
wood, for example.
If this is a carpet and pad installation over concrete it is
unlikely that spikes will work anyway, IME.
>> Anyone heard of a kit to convert four spikes to three?
>>
Some speaker manufactures use only three spikes. Two
in the front and one in the back. This makes adjusting
tweeter face rake adjustments much easier too.
>> It would have to fit beneath the existing arrangement as I don't
>> want to modify the speakers (which are Dynaudio Audience
>> 62 floorstanders).
> >
Spike sources, check out:
http://www.madisound.com/catalog/index.php?cPath=404_121
http://www.musicdirect.com/category/49
Quality casters make a good alternative (measured
reduction in cabinet vibration) to speaker spikes, IME.
They also give you the ability to move the speakers
about freely.
>> I'm thinking of something like a heavy duty plate with four solid
>> fittings above and three below. I suppose an alteration to the sound
>> is inevitable but would avoid scrap the idea if it has too much
>> effect.
>
>
>> An alternative is to put paving slabs on top of the carpet beneath the
>> speakers. They should be heavy enough to not move and also present a
>> more uniform surface for the speakers though even that would not be
>> perfect. The slight problem here is the slabs sold by the local stores
>> are fairly lightweight.
>
This is the least desirable of the alternatives you've site so far.
Oct, 2000 , TAS - What's Wrong With Speakers
by R.E. Greene
"But as soon as a speaker gets an input signal, it
starts doing things it shouldn't and starts making
noise, not just the music it should be making. Cones
and surrounds flexing, mechanical structures
vibrating, cabinets flexing in unpredicted and
unpredictable ways, air flowing turbulently,
electrostatic diaphragms vibrating chaotically
on the scale of small areas even if they are moving
regularly on a large scale, such sources of noise
are everywhere."
"How much noise are we talking about here?
A lot, a whole lot by the standards of noise
levels in electronics and recording systems.
Speaker noise appears only 20 to 30 dB down
from signal in some cases, and even the
cleanest speakers I know do not get the noise
down much more than 55 dB or so."
Jim Lesurf
<nos...@noquacking.com> wrote:
> "James Harris" wrote
> >> My speakers have four spikes beneath them which makes it a pain to
> >> move the speakers even slightly as the length of at least one spike
> >> has to be adjusted to make all four rest on/in the floor. (The floor
> >> is solid - maybe concrete - and not wood.)
> >
> "concrete"... is a very good vibration sink compared to wood, for
> example.
What size/shape/structure/type of "concrete" do you have in mind, and what
do you mean by "sink"? Can you point <pun> me at measurements to support
what you say?
> If this is a carpet and pad installation over concrete it is unlikely
> that spikes will work anyway, IME.
"Work" means?...
> Quality casters make a good alternative (measured reduction in cabinet
> vibration) to speaker spikes, IME.
Ah. Thanks, can you give a URL for the measurements you are referring to
here?
Slainte,
Jim
--
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html
Powell
"Jim Lesurf" wrote
>> >> My speakers have four spikes beneath them which makes it a pain to
>> >> move the speakers even slightly as the length of at least one spike
>> >> has to be adjusted to make all four rest on/in the floor. (The floor
>> >> is solid - maybe concrete - and not wood.)
>> >
>> "concrete"... is a very good vibration sink compared to wood, for
>> example.
>
> What size/shape/structure/type of "concrete" do you have in mind, and what
> do you mean by "sink"? Can you point <pun> me at measurements to support
> what you say?
>
In theory, all things being equal (concrete's mass will convert
more sound energy to heat more efficiently as compared to wood
which tends to resonate. Many high end speaker manufactures
like Wilson Audio, B&W, Egglestonworks and others
construct speaker cabinets out of synthetic compounds,
stone, or aluminum for this reason., for example. Of course
in practice it is more a complicated subject because of Q
value effects.
Meausrements... yes, I have data. What is your specific
question?
>> If this is a carpet and pad installation over concrete it is unlikely
>> that spikes will work anyway, IME.
>
> "Work" means?...
>
For maximum effectiveness spikes should not be run
through any type of carpet interface (carpet/foam).
If you have high quality carpet, spikes just won't
penetrate the carpet/pad substrate. The tightly
woven jute backing and under pad is the problem.
The conical shape of spikes simply will not couple
to the sub-floor... and I mean tightly. While it might
appear (feel) to you that your spikes are firmly in
they are still supported by the carper/pad. Sound
pressure measurements and auditioning indicate
only a poor improvement in fidelity if used in this way.
>> Quality casters make a good alternative (measured
>> reduction in cabinet vibration) to speaker spikes, IME.
>
> Ah. Thanks, can you give a URL for the measurements
> you are referring to here?
>
I've not placed this data on the web.
Keith G
:-)
I've got a number of these racks - they were cheap as chips from Argos and
they're very strong!
(They figure in every shot of a kitchen I've seen lately and I've even seen
them posing as 'fixtures' in a submarine in some tossy film!!)
Eiron
> For maximum effectiveness spikes should not be run
> through any type of carpet interface (carpet/foam).
> If you have high quality carpet, spikes just won't
> penetrate the carpet/pad substrate. The tightly
> woven jute backing and under pad is the problem.
> The conical shape of spikes simply will not couple
> to the sub-floor... and I mean tightly.
You don't think that spikes will penetrate Jute? But that doesn't mean it wouldn't be fun trying.
Anyway, you are wrong. I just tried pushing a Tannoy spike through a piece of decent carpet
and underlay into my finger. It didn't take much force at all.
--
Eiron.
Rob
snip
>>
> For maximum effectiveness spikes should not be run
> through any type of carpet interface (carpet/foam).
> If you have high quality carpet, spikes just won't
> penetrate the carpet/pad substrate.
If by pad you mean underlay, spikes I've used just do. Certainly helps a
lot with wobble, especially with small footprint floor standing speakers.
The tightly
> woven jute backing and under pad is the problem.
> The conical shape of spikes simply will not couple
> to the sub-floor... and I mean tightly.
What do you mean by a sub-floor? Floor?!
Rob
Jim Lesurf
<nos...@noquacking.com> wrote:
> "Jim Lesurf" wrote
> >> >> My speakers have four spikes beneath them which makes it a pain to
> >> >> move the speakers even slightly as the length of at least one
> >> >> spike has to be adjusted to make all four rest on/in the floor.
> >> >> (The floor is solid - maybe concrete - and not wood.)
> >> >
> >> "concrete"... is a very good vibration sink compared to wood, for
> >> example.
> >
> > What size/shape/structure/type of "concrete" do you have in mind, and
> > what do you mean by "sink"? Can you point <pun> me at measurements to
> > support what you say?
> >
> In theory, all things being equal (concrete's mass will convert more
> sound energy to heat more efficiently as compared to wood which tends to
> resonate.
Afraid that reads like a rather muddled set of assertions to me. Which "all
things" are you setting "equal"? What do you mean by "concrete's mass"? Do
you mean 'density', or what?
How does 'concrete' having 'mass' mean it disspates vibration more easily
than the same 'mass' of wood?
What about the question of coupling between the different mechanical
impedances which may mean that less energy transfers? etc, etc.
All solid structures have a tendency to 'resonate'. But since you still say
nothing about the structral sizes and shapes, nor the internal wave
impedances, velocities, or dissipation factors, nor how the coupling
depends on many factors, your assertion isn't one you have actually
explained.
> Many high end speaker manufactures like Wilson Audio, B&W,
> Egglestonworks and others construct speaker cabinets out of synthetic
> compounds, stone, or aluminum for this reason., for example. Of course
> in practice it is more a complicated subject because of Q value effects.
> Meausrements... yes, I have data. What is your specific question?
Provide the specific measurements (and how you did them) that back up the
specific assertions you make above. We could then decide if your views are
supported by measurements you (or others) have made, nor not.
> >> If this is a carpet and pad installation over concrete it is unlikely
> >> that spikes will work anyway, IME.
> >
> > "Work" means?...
> >
> For maximum effectiveness spikes should not be run through any type of
> carpet interface (carpet/foam).
You have now traded one word (work) you didn't define for a phrase
(effectiveness) which you also haven't defined. What is your measureable
definition for these terms?
> If you have high quality carpet, spikes just won't penetrate the
> carpet/pad substrate.
Well, I do have spikes on one of the pairs of speakers I use. And I had no
trouble getting them to penetrate the thick carpet and underlay. However I
don't know that the spikes do much beyond stopping the speakers wobbling a
bit if I bump into them. However...
The problem here is as already referred to in this thread. That various
people make all kinds of confident assertions about how spikes/cones
'work'. But they often do so in vague and sweeping ways, providing no
evidence beyond assertions. And the 'reasons' they assert often conflict
with one another. This seems to apply both to the behaviour of spikes, and
the behaviour of the materials and objects they link.
> >> Quality casters make a good alternative (measured reduction in
> >> cabinet vibration) to speaker spikes, IME.
> >
> > Ah. Thanks, can you give a URL for the measurements you are referring
> > to here?
> >
> I've not placed this data on the web.
OK. So you are just presenting your opinions without presenting any of your
(claimed) evidence. Thus no-one can tell if what you claim stands up, or
that your evidence actually supports your assertions. Nor, indeed, if you
actually have any evidence.
Since my background is in science and engineering, I do tend to prefer to
base my own conclusions on being able to assess measured evidence, and the
details of how those measurements were obtained. Given that consumer audio
is awash with 'technobabble' I tend to place more reliance on that than on
simply accepting assertions.
Thus far I am left with the feeling that your assertions do muddle up
different physical properties. This isn't unusual. Many people with no
serious background in physical science or engineering can confuse things
like 'strength' and 'rigidity', 'mass' and 'density', etc, etc. However if
you don't provide any measurements of your own, and can't even point to
ones by others that support your assertions, I can't reach an actual
conclusion. I can only decide that your opinions have not been given any
reliable basis upon which others can assess them.
FWIW I think Keith Howard did do some measurements on some of the effects
of 'spikes' a few years ago for HFN. I also think there are lists of values
of the relevant material properties in 'Structure-Borne Sound' by Cremer,
Heckl, and Ungar. I do have a copy of that[1] and the magazines. So I'll
have a look if I get a chance and see what the data indicates. BTW IIRC
materials like 'wood' and 'concrete' have ranges of material values that do
cover quite large ranges. Be interesting to refresh my memory on this when
I have a chance. :-)
Slainte,
Jim
[1] Cost a fortune and reads like the English is still in German. 8-] But
is packed with some interesting data and analysis. Recommended to anyone
with a serious interest in this topic who doesn't mind being faced with
some 'hard sums' maths. ;->
Jim Lesurf
> snip
> >>
> > For maximum effectiveness spikes should not be run
> > through any type of carpet interface (carpet/foam).
> > If you have high quality carpet, spikes just won't
> > penetrate the carpet/pad substrate.
> If by pad you mean underlay, spikes I've used just do. Certainly helps a
> lot with wobble, especially with small footprint floor standing speakers.
Indeed, I've just remembered that the pair of LS3/5A's I have on stands in
the dining room also have spikes - for the same reason as you mention. On
tall stands and wobble alarmingly or may move around if bumped into unless
spiked. They also penetrate though quite a thick carpet and underlay.
Maybe none of us have "high" enough "quality" carpet. Can't say as yet as
these are also words Powell has used without providing a measurable
definition. The phrase "vague and sweeping assertions" does come to mind.
Maybe "sweeping" is relevant for carpets, though... :-)
Powell
"Jim Lesurf" wrote
The spiked speaker act as a spring component (albeit a rather stiff one).
The potential positive effect of spikes is related to the speaker-floor
coupling this spring component causes.
The speaker-floor coupling is a (more or less damped) resonnant system.
Below the resonnance frequency, the speaker & floor acts as one solid unit.
If you have a rigid, heavy floor (concrete etc), you might experience clean
bass with maximum attack. Hi-fi bass at it's best? With a lively (wooden
etc.) floor, the floor - and maybe even the walls - may act as passive
transducers totally out of control. If you can feel the bass coming through
your feet or your chair (as opposed to hitting your stomach & chest) this is
probably what caused it. Hi-fi bass at it's worst!
Above the resonnance frequency, the speaker is practically decoupled from
the floor. Whether this causes "the tail wagging the dog" in an audible
sense depends on speaker mass, cone mass, speaker center of inertia and cone
location on speaker. In most cases this effect will be neglible. But if the
resonnance frequency is very low (say, 15 Hz) - and if the speaker is
lightweight (30-40 Lbs) - you may get compressed transient response,
particularly from the bass element.
What's now left is the region around the resonnance frequency. A lot of
unwanted things may happen here. The speaker-floor coupling will have a Q
value, determining how well-damped the resonnance is. Poor damping may cause
significant problem in this region - due to speaker vibration.
For a given speaker, the speaker-floor coupling (be it spikes, squash balls,
rubber wheels, MDF etc), defines the resonnant frequency and the Q value of
the coupling. Spikes will typically move the resonnant frequency up somwhere
in the midrange , and the system will have a relatively high Q-value. While
(in some cases) improving bass performance, this may create audible problems
in the midrange. Remove the spikes and you may replace midrange problems
with similar (but not neccessarily similar sounding) problems in the bass
region. You cannot move the resonnance frequency above audible range (20
kHz) - which is why you might have to compromise.
Another strategy is to move the resonnance down in frequency with silent
feet, rubber weels etc. With heavy speakers you can move the resonnance
frequency well below 20 Hz - out of audible range. In addition the bass
output will be as clean as you've ever heard, but you might be loosing some
attack due to the decoupling from the floor (or maybe you're just addicted
to "hi-fi bass"). Compromise here too? Maybe not.
Allthough the sonic effects of spikes may vary from speaker to speaker and
from room to room, they do move the resonnance of the speaker-floor combo up
in frequency. Sometimes it improves overall sound, sometimes it doesn't. But
the effects have a very natural explanation.
>> Many high end speaker manufactures like Wilson Audio, B&W,
>> Egglestonworks and others construct speaker cabinets out of synthetic
>> compounds, stone, or aluminum for this reason., for example. Of course
>> in practice it is more a complicated subject because of Q value effects.
>
>> Meausrements... yes, I have data. What is your specific question?
>
> Provide the specific measurements (and how you did them) that back up the
> specific assertions you make above. We could then decide if your views are
> supported by measurements you (or others) have made, nor not.
>
Who is "we"? You don't speak for anyone but yourself, Lesurf.
> Since my background is in science and engineering,
>
There are ZERO qualifications, not even a Drivers License,
for someone to call themselves a "Engineer". What kind of
formal education in engineering do you have...
undergraduate/graduate and in what field?
> I do tend to prefer to base my own conclusions on being able
> to assess measured evidence, and the details of how those
> measurements were obtained.
>
I understand. I've run about 23 batches of tests, as I recall, several
years back. If I have time I'll post something.
> Given that consumer audio is awash with 'technobabble' I tend to
> place more reliance on that than on simply accepting assertions.
>
You enjoy intellectualizing but it would behoove you to get off your
penguin butt and do the work yourself.
Wally
> Allthough the sonic effects of spikes may vary from speaker to
> speaker and from room to room, they do move the resonnance of the
> speaker-floor combo up in frequency. Sometimes it improves overall
> sound, sometimes it doesn't. But the effects have a very natural
> explanation.
Care to explain the mechanism that causes the resonant frequency to move up?
>> Given that consumer audio is awash with 'technobabble' I tend to
>> place more reliance on that than on simply accepting assertions.
>>
> You enjoy intellectualizing but it would behoove you to get off your
> penguin butt and do the work yourself.
What makes you think he doesn't/hasn't? It's you that's making certain
claims about the effects of spikes, and the onus is on you to support those
claims with evidence. The fact that he's asking for evidence doesn't
preclude him having done his own research already.
--
Wally
www.wally.myby.co.uk
You're unique - just like everybody else.
Jim Lesurf
<nos...@noquacking.com> wrote:
> "Jim Lesurf" wrote
[big snip of assertions and opinions]
> >
> >> Meausrements... yes, I have data. What is your specific question?
> >
> > Provide the specific measurements (and how you did them) that back up
> > the specific assertions you make above. We could then decide if your
> > views are supported by measurements you (or others) have made, nor not.
> >
> Who is "we"?
This is usenet, and these postings are going to a number of groups. Chances
are you and I aren't the only people reading this. Surprised if you didn't
know this. Or is your question purely a debating tactic?
> You don't speak for anyone but yourself, Lesurf.
Ah,you seem to have adopted the 'Go for the man, not the ball' debating
tactic. And employed the tone of 'Headmaster telling off the naughty
schoolboy who dared to ask impertinent questions'. :-)
...or as just a debating tactic to cover for not actually answering my
questions and providing the measurements you say you have. Is the idea
now to try and get a personal argument going to smokescreen that? :-)
> > Since my background is in science and engineering,
> >
> There are ZERO qualifications, not even a Drivers License, for someone
> to call themselves a "Engineer". What kind of formal education in
> engineering do you have... undergraduate/graduate and in what field?
Ah, yes. Looks like you do prefer "go for the man not the ball" instead of
dealing with the substance.
You seem to overlooked that you haven't yet provided any measurements or
details of how you obtained them. Lacking that, how could anyone else say
if a given background would be appropriate to judge what you did? And the
point of my "we" above was that once you 'publish' your data every/any
individual reading this could make up their own mind about your assertions
without having to take either me or you as an 'expert'.
I'm not bothered if you doubt I am 'qualified' or not. Nor if someone else
has doubts. In physical science and engineering, people decide on the
evidence, not on the basis of simply accepting that someone is 'qualified'
so must be right. I just wanted to see what evidence you could offer for
your assertions and claims.
BTW Note that you introduced "qualifications" as if they were a test of
some kind. Not me. Then snipped the explaination I gave for why I was
saying what I was. Although if you want to call me 'Lesurf' you could be
more accurate and call me 'Dr Lesurf' purely for the sake of form. :-)
Maybe even put letters like IEEE and AES somewhere after my name, I guess.
But I agree with you that 'Dr' in front of my name, etc, doesn't ensure I
could judge your measurements. Hence I don't normally use the 'Dr', etc, as
it seems irrelevant. Particularly when there are no presented measurements
to actually consider. :-)
I'm quite happy to leave others reading this to make up their own mind on
the basis of what you've said, and how you have responded. That should set
your mind at rest if you fear I might lack the required 'qualifications'
you would demand for anyone who dared to examine your measurements in a
critical manner. :-)
> > I do tend to prefer to base my own conclusions on being able to assess
> > measured evidence, and the details of how those measurements were
> > obtained.
> >
> I understand. I've run about 23 batches of tests, as I recall, several
> years back. If I have time I'll post something.
Look forwards to it. :-) Please post the announcement in all the groups
this is going to if you wish everyone reading your assertions to be able to
make up their own minds and decide for themselves if your measurements
actually support what you have claimed.
> > Given that consumer audio is awash with 'technobabble' I tend to place
> > more reliance on that than on simply accepting assertions.
> >
> You enjoy intellectualizing but it would behoove you to get off your
> penguin butt and do the work yourself.
Thanks for your help. Your response does help me make an interim assessment
of your assertions whilst I await any evidence you eventually produce.
Slainte,
Jim
Jim Lesurf
<at...@dotat.atdot> wrote:
> Powell wrote:
> > Allthough the sonic effects of spikes may vary from speaker to speaker
> > and from room to room, they do move the resonnance of the
> > speaker-floor combo up in frequency. Sometimes it improves overall
> > sound, sometimes it doesn't. But the effects have a very natural
> > explanation.
> Care to explain the mechanism that causes the resonant frequency to move
> up?
FWIW I decided not to comment on the bulk of the items asserted most
recently as I didn't want to widen the issues. But a number of questions
like the above did occur to me. The problem is that with no measurements,
details of experimental arrangements, etc, it is often hard to assess the
assertions people make.
> >> Given that consumer audio is awash with 'technobabble' I tend to
> >> place more reliance on that than on simply accepting assertions.
> >>
> > You enjoy intellectualizing but it would behoove you to get off your
> > penguin butt and do the work yourself.
> What makes you think he doesn't/hasn't? It's you that's making certain
> claims about the effects of spikes, and the onus is on you to support
> those claims with evidence. The fact that he's asking for evidence
> doesn't preclude him having done his own research already.
Nor is it a requirement that someone must already have done their own
personal measurements to ask for the measurements someone else claims to
already have to support their assertions.
The point of the scientific approach is that anyone who wishes can make
their own decisions *based on the presented evidence*. Not on the basis
that they must accept that the person making the assertions is an
'authority' who must not be questioned or doubted. Access to the
measurements and details of how they were done allows anyone who wishes to
come to their own conclusions.
So for me the key point is the middle one made above. That Powell is making
a series of assertions and claiming to have 'measurements' to back them up.
As is the norm in physical science and engineering, this means we judge the
assertions by examination of the evidence. Up to the person making the
assertions to provide this. I see no reason at present to doubt he does
have 'measurements', but none of us can judge their value without seeing
them and knowing the details of how they were obtained. Hence my questions
to him.
I have noticed over they years that it is quite common on usenet (and
perhaps in audio in particular) for some people to react to being asked for
mere evidence or an explanation that can be tested on the basis of
estabilished physical science as if being asked was a 'personal attack'.
Hence responses using debating or other tactics like 'go for the man' for
daring to question the asserted 'wisdom'. To me that seems at best an
irrelevance, and at worst a smokescreen preventing each person from being
able to form their own conclusions on the basis of the *evidence*. I have
no real interest in debating games or personal arguments. So if no
measurements are forthcoming I am content to leave the matter here and
allow each person reading this thread to come to their own conclusions.
Slainte,
Jim
Geoff Mackenzie
Geoff Mackenzie
>
>> There are ZERO qualifications, not even a Drivers License, for someone
>> to call themselves a "Engineer". What kind of formal education in
>> engineering do you have... undergraduate/graduate and in what field?
>
Really? Would you care to explain that to my daughter, who gained her
degree in Mechanical Engineering from Coventry a few years ago? Or her
grandfather, who did the same degree (different Uni - I think Oxbridge, but
can't remember - it was pre-war) and among other things certificated the
Olympus engines fitted to Concorde but to the end of his days was happy to
describe himself as an "engineer"?
Zero qualifications? I don't think so.
Geoff MacK
Geoff Mackenzie
"Geoff Mackenzie" <gm...@chapterfive.org.uk> wrote in message
news:7fq1kbF...@mid.individual.net...
Sorry, didn't mean to post twice - still failing to get to grips with Vista,
which I find actively user-hostile.
Geoff MacK
Rob
I think there's 'qualifications', and 'qualified'.
Personally, I don't think having an academic degree necessarily
qualifies someone as anything. Doing/building/designing (etc) does. Not
sure what your daughter would say - I suspect she might agree.
And qualifications are not required to gain chartered engineering status
in a number of fields - they certainly help, though. Whether that means
they're any good is a different matter altogether.
And and and, you can call yourself whatever you want - don't make it so
though :-)
Rob
David Looser
news:qZRlm.72914$OO7....@text.news.virginmedia.com...
>
> And qualifications are not required to gain chartered engineering status
> in a number of fields -
Well of course chartered status is a qualification in itself, but I am not
aware of any body that will award chartered status without the candidate
already having appropriate academic qualifications. Perhaps you can
elaborate if you believe otherwise.
David.
>
> And and and, you can call yourself whatever you want - don't make it so
> though :-)
>
Not anything, certain job titles, such as "architect" are reserved to those
with appropriate qualifications. Though I agree that the term "engineer"
isn't one of them.
David.
Joe Kotroczo
Looser" <david....@btinternet.com> wrote:
(...)
>
> Not anything, certain job titles, such as "architect" are reserved to those
> with appropriate qualifications. Though I agree that the term "engineer"
> isn't one of them.
It is in most countries. In some countries, it's even used as a honorific,
similar to "Dr." or "MD" for doctors.
--
Joe Kotroczo kotr...@mac.com
Geoff Mackenzie
"Rob" <patchoul...@gmail.com> wrote in message
news:qZRlm.72914$OO7....@text.news.virginmedia.com...
>>
>>
>>
>>>
>>>> There are ZERO qualifications, not even a Drivers License, for someone
>>>> to call themselves a "Engineer". What kind of formal education in
>>>> engineering do you have... undergraduate/graduate and in what field?
>>>
>>
>> Really? Would you care to explain that to my daughter, who gained her
>> degree in Mechanical Engineering from Coventry a few years ago? Or her
>> grandfather, who did the same degree (different Uni - I think Oxbridge,
>> but can't remember - it was pre-war) and among other things certificated
>> the Olympus engines fitted to Concorde but to the end of his days was
>> happy to describe himself as an "engineer"?
>>
>> Zero qualifications? I don't think so.
>>
>
> I think there's 'qualifications', and 'qualified'.
Define your terms.
> Personally, I don't think having an academic degree necessarily qualifies
> someone as anything. Doing/building/designing (etc) does. Not sure what
> your daughter would say - I suspect she might agree.
Ah - "I qualified in the University of Life". I think that my daughter
would agree that a few years waving a spanner or a soldering iron around
doesn't make up for a decent academic background in the fundamentals. Of
course, you'd have to ask her.
>
> And qualifications are not required to gain chartered engineering status
> in a number of fields - they certainly help, though. Whether that means
> they're any good is a different matter altogether.
>
Really? What fields? University of Eastern Florida comes to mind....
> And and and, you can call yourself whatever you want - don't make it so
though :-)
Sure, I can call myself "Reverend" or "Lord". As you say, don't make it
so. But a decent degree from a recognised university followed by practical
experience makes it more likely that you can achieve some sort of career.
Geoff MacK
Scott Dorsey
Jim Lesurf <jc...@audiomisc.co.uk> wrote:
>In article <JtKdnWbo-os8igrX...@giganews.com>, Wally
><at...@dotat.atdot> wrote:
>> Powell wrote:
>
>> > Allthough the sonic effects of spikes may vary from speaker to speaker
>> > and from room to room, they do move the resonnance of the
>> > speaker-floor combo up in frequency. Sometimes it improves overall
>> > sound, sometimes it doesn't. But the effects have a very natural
>> > explanation.
>
>> Care to explain the mechanism that causes the resonant frequency to move
>> up?
>
>FWIW I decided not to comment on the bulk of the items asserted most
>recently as I didn't want to widen the issues. But a number of questions
>like the above did occur to me. The problem is that with no measurements,
>details of experimental arrangements, etc, it is often hard to assess the
>assertions people make.
I believe that Mr. Powell is a troll. However, I do suggest looking at
the following:
1. A system with two masses, one very large and one very small, which are
loosely coupled by a flexible joint.
2. A system with two masses, one very large and one very small, which are
more tightly coupled.
If the masses are the same in these two examples, and you look at the response
to excitation of the smaller mass, what happens to the main resonance as the
coupling is increased? Hint: both the resonant frequency and the Q are
changed.
This stuff is easy to model as a two mass spring system, in the simplest cases.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Scott Dorsey
Here in Virginia, these people could not legally call themselves engineers
unless they have passed the PE examination. The PE exam is fairly difficult.
In some other places, anyone can call themself an engineer, no matter what
kind of education and experience they ahve.
Places differ.
Arkansan Raider
It's been my experience that the guy pushing faders is generically
called the "sound engineer," and that is fully interchangeable in common
usage with "sound man" or "sound guy."
Thanks for bringing that to my attention. I won't be making that mistake
again.
To be honest, I don't know why I didn't think about that before. I don't
call my professors "Doctor" unless they've earned that degree.
Friggin' duh. <g>
/palm to forehead
---Jeff
Geoff Mackenzie
"Joe Kotroczo" <kotr...@mac.com> wrote in message
news:C6BDBEA0.9F98D%kotr...@mac.com...
his profession (he was an aeronautical engineer) but when he signed my
wedding certificate as "engineer" I would swear the Vicar looked for the
gease under his fingernails....
Considering we (in England) engendered the industrial revolution, I do
wonder why we don't give the term "engineer" the respect it deserves.
Geoff MacK
Scott Dorsey
>
>It's been my experience that the guy pushing faders is generically
>called the "sound engineer," and that is fully interchangeable in common
>usage with "sound man" or "sound guy."
Yes, this is not legal in Virginia. The Society of Broadcast Engineers is
currently petitioning the state to make an SBE certification or an old FCC
First Phone License a legal identification to call yourself a broadcast
engineer, however.
>Thanks for bringing that to my attention. I won't be making that mistake
>again.
I have had folks get into big trouble with it when bidding for state
contracts.
>To be honest, I don't know why I didn't think about that before. I don't
> call my professors "Doctor" unless they've earned that degree.
"You can call me doctor, but you'd be wrong because I have a Master's
degree. You can call me professor but you'd be wrong there too because
I'm a lecturer. So call me Colonel."
-- Col. Pasafiume
People get touchy about these kinds of things.
Joe Kotroczo
Mackenzie" <gm...@chapterfive.org.uk> wrote:
I suspect the explanation is linguistical. The word "engine". In French
"engin" means "device", and in German, there is no direct descendant of the
the latin "ingenium". Both languages translate the English "engine" into
either "motor" or "machine", depending on context.
--
Joe Kotroczo kotr...@mac.com