speaker magnet size?
Arch-lab
I have been told the size of the magnet on a speaker relates to the
"quality" even if they have the same power rating.
1. Is that true?
2. If it is true, then it is best to buy the largest magnet?
I.e. I have seen two 50W raw midrange speakers, yet the cheaper one has a
13oz. magnet and the expensive one has a 4oz. magnet. So that wouldn't jive
with the above claim...
(actually, i've seen several cases like this on electronic supplier's
sites).
thankyou
jim dorey
more than the good stuff.
Arch-lab wrote:
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Kevin Aylward
"Arch-lab" <l...@us.com> wrote in message
news:y6nd8.130912$Rp6.23...@news2.rdc1.ab.home.com...
The main advantage of a bigger magnet is more sound output for a given
electrical input, so its a "quantity" aspect. One might infer that companies
that go to the expense of using large magnets take more effort in designing the
speaker to have better frequency response. I personally do use the size of the
magnet as a purchasing guide, i.e. the bigger the better. My Fender Twin Reverb
is the loudest 100W rated amp I know of and it magnets are very large indeed.
Kevin Aylward , Warden of the Kings Ale
ke...@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.
Rudi Fischer
"Arch-lab" l...@us.com wrote
> I have been told the size of the magnet on
> a speaker relates to the "quality" even if they
> have the same power rating.
> 1. Is that true?
> 2. If it is true, then it is best to buy the largest magnet?
No
> I.e. I have seen two 50W raw midrange speakers,
> yet the cheaper one has a 13oz. magnet and the
> expensive one has a 4oz. magnet. So that wouldn't jive
> with the above claim...
Magnet size != strenght of magnetic field in
air gap (which corresponds to 'force')
(And 'power-rating' != 'quality'!
> (actually, i've seen several cases like this on
> electronic supplier's sites).
As a hint: If you like to have 'good sound',
don't use 'no-names' or surplus unless you have
a lot of experience with diy and good measuring
equipment! Even from one 'series' they 'differ' too much!
And please keep in mind:
(Don't yell at me if you're already doing that!;-))
'Quality' of the woofer, mid or tweeter
!= soundquality of the speaker(system)!
There's the crossover, remember, and that
(and the design/volume of the cabinet) is
by far the most important part!
It's not _that_easy!
> thankyou
you're welcome;-)
Good luck for your project!
HTH
Rudi Fischer - harfe-audio
--
...and may good music always be with you
Ge0
of the magnetic field that matters, not necessarily the size. Some
companies use stronger magnet materials that are more dense than the
materials other manufactures use. Therefore their speakers can be smaller.
For example a quarter sized chunk of Neodymium magnat is more powerful than
a hockey puck size chunck of typical magnat material (sellenium cobalt I
think, or allinco?).
Ge0
*******************************************
Low cost car stereo equipment repair/ modification
Contact me for advice or a quote.
********************************************
Looking for answers on car stereo topics?
www.mobileaudio.com
http://go.to/bcae/
Boris Mohar
>
>I have been told the size of the magnet on a speaker relates to the
>"quality" even if they have the same power rating.
>1. Is that true?
>2. If it is true, then it is best to buy the largest magnet?
Generally yes but the magnet strength is just as important.
>
>I.e. I have seen two 50W raw midrange speakers, yet the cheaper one has a
>13oz. magnet and the expensive one has a 4oz. magnet. So that wouldn't jive
>with the above claim...
Can I interest you in some really expensive speaker wire?
I have seen speakers with huge plastic magnet covers and when pried of
they reveal a peanut sized magnets hiding under.
Regards,
Boris Mohar
VIATRACK Printed Circuit Designs
Michael Black
Or, "shielded speakers" that use another magnet to restrict the magnetic
flow of the magnet that's doing the work. So if you pick up one of
those cheap "computer speakers" it will have a hefty feel, but the
weight is misleading.
I think the "heavier magnet the better" is most significant in
low end items, where the speakers are small, etc. You can't really
get any worse than those speakers, so a speaker with a heavier magnet
pretty much has to be better. I'm still opening things and finding
speakers that aren't significantly better than speakers in "transistor
radios" from thirty years ago, so if someone has something they like
but it has lousy sound, it might be worth putting in a better speaker
of the same size. You see this all the time in rec.radio.shortwave,
where people complain about the sound out of their tiny radios which
are otherwise a technical marvel. Cnange the speaker, or use an outboard
one, and the sound gets a lot better because the puny speaker is no longer
in the way.
Michael
Arch-lab
> > I.e. I have seen two 50W raw midrange speakers,
> > yet the cheaper one has a 13oz. magnet and the
> > expensive one has a 4oz. magnet. So that wouldn't jive
> > with the above claim...
> Magnet size != strenght of magnetic field in
> air gap (which corresponds to 'force')
> (And 'power-rating' != 'quality'!
>
So you are basing this on the different field strengths that can be produced
by different magnets or differing size? i.e. a smaller neodeum. can have a
greater field strength?
So if they use the same type of magnet choose the bigger one is still the
basic idea?
Also, you mention go with name brand then... So say at MCMelectronics, you
would recommend the pioneer over their brand?
http://www.i-mcm.com/Search/search2-level4.jhtml?_DARGS=%2Fcommon%2Fprodsear
chform.jhtml
jim dorey
can be put to it before distortion occurs.
Rudi Fischer wrote:
> (And 'power-rating' != 'quality'!
Fabian P.
> news:y6nd8.130912$Rp6.23...@news2.rdc1.ab.home.com...
>
>> I have been told the size of the magnet on a speaker relates to the
>> "quality" even if they have the same power rating.
>> 1. Is that true?
>> 2. If it is true, then it is best to buy the largest magnet?
>>
>>
>> I.e. I have seen two 50W raw midrange speakers, yet the cheaper one has a
>> 13oz. magnet and the expensive one has a 4oz. magnet. So that wouldn't jive
>> with the above claim...
>> (actually, i've seen several cases like this on electronic supplier's
>> sites).
>>
>
> The main advantage of a bigger magnet is more sound output for a given
> electrical input, so its a "quantity" aspect. One might infer that companies
> that go to the expense of using large magnets take more effort in designing the
> speaker to have better frequency response. I personally do use the size of the
> magnet as a purchasing guide, i.e. the bigger the better. My Fender Twin Reverb
> is the loudest 100W rated amp I know of and it magnets are very large indeed.
Since a speaker magnet is glued to the pole plates with a VERY strong
adhesive, it is very difficult to disassembly the magnetic assembly
of a speaker without destroying it. Whit this in mind, and for obvious
marketing reasons, some speaker manufacturers use magnets with large
outer diameter in they speakers so they appear to have a big magnet, but
inside, the magnet's inner diameter is very close to the outer
dimension, which in fact results in a small net magnetic surface.
So, given two speakers with the same magnetic material, you shouldn't
judge by their magnet size but its weight.
Bob Wilson
says...
>
>
>I have been told the size of the magnet on a speaker relates to the
>"quality" even if they have the same power rating.
>1. Is that true?
No. That statement taken in isolation is compelete BS. Thes is the sort of
thing that people who are ignorant about the design principles of speakers
will tell you. First, physical size of the magnet is totally irrelivant.
Ceramic magnets are far less paoweful than alnico or rare-earth magnets of
the same size. Second, in an "air suspension" (sealed box) design,
increasing the magnet size beyond the optimum size will increase mid range
efficiency (i.e. volume output) but it will REDUCE bass output, because it
leads to overdamping and this causes an early bass rolloff. Conversely, a
magnet that is insufficiently strong, may reduce midrange output, but it
will cause an undamped peak in bass that appears to the unskilled lietener
as "better" bass. It actually is "one-note" bass (like the sound of a boom
car)m and the bass is muddy sounding becaus of the poor electrodynamic
damping.
>2. If it is true, then it is best to buy the largest magnet?
No, that is just plain stupid. Only a fool buys speakers by the pound.
>I.e. I have seen two 50W raw midrange speakers, yet the cheaper one has a
>13oz. magnet and the expensive one has a 4oz. magnet. So that wouldn't jive
>with the above claim...
>(actually, i've seen several cases like this on electronic supplier's
>sites).
That is because there are different types of magnets, with different
strengths, AND there are different speaker designs that REQUIRE different
magnet strengths for optimal operation. Low performance ceramic magnets are
dirt cheap, and many manufacturers of cheap speakers put on a huge, low
strength, cheap magnet to act as "sucker bait" to attract technically
ignorant customers.
There is HELL of a lot more to speaker quality than magnet size.
Bob.
Kevin Aylward
news:3C76E053...@mail.com...
Ahmmm... I took it as read that I was referring to the weight of the speaker and
not its physical size, despite using the word "bigger". This should have been
trivially obvious. You'll note the original context of the post was discussing
the weight in oz's, not physical size. I can assure that my fender twin is the
heaviest combo I have ever lifted.
"I never said we was bigger then Jesus, I said we were taller" - The Rutles,
take off of the Beatles.
Peter
>>
... I have seen two 50W raw midrange speakers, yet the cheaper one has a 13oz.
magnet and the expensive one has a 4oz. magnet ...
>>
Incredible.
The LF magnet in an Altec-Lansing 604 (15" co-axial) weighs in at abour 46
ounces.
The same basic LF driver is used in many movie theaters where it is called the
416.
30 watts will fill an entire auditorium.
Kevin Aylward
news:u7efrac...@corp.supernews.com...
> In article <y6nd8.130912$Rp6.23...@news2.rdc1.ab.home.com>, l...@us.com
> says...
> >
> >
> >I have been told the size of the magnet on a speaker relates to the
> >"quality" even if they have the same power rating.
> >1. Is that true?
>
> No. That statement taken in isolation is compelete BS. Thes is the sort of
> thing that people who are ignorant about the design principles of speakers
> will tell you. First, physical size of the magnet is totally irrelivant.
> Ceramic magnets are far less paoweful than alnico or rare-earth magnets of
> the same size. Second, in an "air suspension" (sealed box) design,
> increasing the magnet size beyond the optimum size will increase mid range
> efficiency (i.e. volume output) but it will REDUCE bass output, because it
> leads to overdamping and this causes an early bass rolloff. Conversely, a
> magnet that is insufficiently strong, may reduce midrange output, but it
> will cause an undamped peak in bass that appears to the unskilled lietener
> as "better" bass. It actually is "one-note" bass (like the sound of a boom
> car)m and the bass is muddy sounding becaus of the poor electrodynamic
> damping.
>
> >2. If it is true, then it is best to buy the largest magnet?
>
> No, that is just plain stupid. Only a fool buys speakers by the pound.
>
Call me a fool then. I have been using that technique for well over 20 years
when choosing guitar speakers, and guess what. It works. There are invariable
the loudest and sound great, usually.
> >I.e. I have seen two 50W raw midrange speakers, yet the cheaper one has a
> >13oz. magnet and the expensive one has a 4oz. magnet. So that wouldn't jive
> >with the above claim...
> >(actually, i've seen several cases like this on electronic supplier's
> >sites).
>
> That is because there are different types of magnets, with different
> strengths, AND there are different speaker designs that REQUIRE different
> magnet strengths for optimal operation. Low performance ceramic magnets are
> dirt cheap, and many manufacturers of cheap speakers put on a huge, low
> strength, cheap magnet to act as "sucker bait" to attract technically
> ignorant customers.
>
> There is HELL of a lot more to speaker quality than magnet size.
>
However, in practise, the weight of the magnet does still tell you quite a lot.
I think that you are not addressing the economic realities rather then the
technical aspects of what makes a good speaker. If we assume that a decent
manufacture uses say, non-ceramic magnets, they simply don't, in general, put
heavier magnets on speakers if a smaller one will achieve the same aim. Its
simple not cost effective.
John Woodgate
wrote (in <20020223030926...@mb-fi.aol.com>) about 'speaker
magnet size?', on Sat, 23 Feb 2002:
>
>>>
>... I have seen two 50W raw midrange speakers, yet the cheaper one has a 13oz.
>magnet and the expensive one has a 4oz. magnet ...
>>>
>
>Incredible.
If they were both nickel-iron or ferrite magnets, yes. But the 4 oz
magnet is probably samarium-cobalt or neodymium-iron-boron.
>
>The LF magnet in an Altec-Lansing 604 (15" co-axial) weighs in at abour 46
>ounces.
>
>The same basic LF driver is used in many movie theaters where it is called the
>416.
>
>30 watts will fill an entire auditorium.
>
These are *mid-range* drivers, which means that cone excursion is a
great deal less than for bass drivers, so a much thinner top-plate is
OK, Thus you need much less magnet mass for a given induction in the
gap.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!
Rudi Fischer
"Arch-lab" <l...@us.com> wrote
> > air gap (which corresponds to 'force')
> > (And 'power-rating' != 'quality'!
> So you are basing this on the different field strengths
> that can be produced
> by different magnets or differing size?
material of a magnet doesn't mean you'll get the same
Bl out of it for sure. In manifacturing a speaker
you'll have to magnetize it _after_ the assembling
process - and you can do that 60, 80 or 100%
of what is possible. And you (sorry, I!)
can do it well on fridays and f*** it up on mondays...;-)
That's one - _checking_ for 'quality'!
Sadly a speaker isn't electronics: 'go, no go'!
And there are (invisible) constructive details like the
shape of the pole piece (to 'focus' the field),
the volume of the air gap, how many layers
in (up to 4) and diameter of the voice coil etc.
All that goes into 'force', 'sound' and (electric) power
rating. (But there are _acoustic- limitations of
SPLmax too- such as Xmax -maximum excursion!)
> i.e. a smaller neodeum. can have a
> greater field strength?
It had in every one I measured - and I think,
that's very reasonable:
Nobody in his right mind would waste an up to 10 times
more expensive magnet by doing it wrong and just using
'standard' parts and parameters for the rest of it.
And using neodymium, samarium-cobalt, AlNiCo
(Lowther) magnets is AFAIK the only way to 'saturate'
pole piece and plate, thus reducing distortion.
(Please correct me, if I'm wrong.)
> So if they use the same type of magnet
> choose the bigger one is still the
> basic idea?
As I think, I explained, no! As everywhere in life:
There's more to using things right, than just size!;-)
> Also, you mention go with name brand then...
> So say at MCMelectronics, you
> would recommend the pioneer over their brand?
> http://www.i-mcm.com/Search/search2-level4.jhtml?
>_DARGS=%2Fcommon%2Fprodsearchform.jhtml
Sorry, couldn't use the link, just showed
the 'search' form. So I can't comment on that.
But sorry again: I wouldn't regard Pion**r a 'serious'
brand in speakers (hifi or pro). (It's a 'big' one, but...)
I would do so with JBL, EV, Vifa, SEAS, Audax,
ScanSpeak, Peerless, Focal, Jordan, Dynaudio,
Davis, Beyma, Thiel, Eton, Morel, ESS,
Audiotechnology etc. etc.
There are (much!) more of them, PA
(in the US and UK) for sure.
Back in the 80's I used others (bass, mid and high
-no, I will not name them!) and found it too difficult
to match pairs.
You had to buy 6, had to measure them and
could use only 2.
(DeltaSPL >3dB, Qes 15%, Bl >20% variation)
They all 'looked' very impressive, but
- just a waste of time - could send 'em back,
of course!;-)
No, they didn't learn and do it well today
- tested it 2 years ago -same procedure as...
I think, they are producing for the industry,
so these can control 'quality'.
Now I stick to mentioned 'brands' and get reliable data
(-ok, most of the time!). Much more 'cost effective'!;-)
Even if you haven't to pay for 'time'!;-)
Bye and good luck for your project!
(Or will this mid be a replacement?
Then be warned: That's no easy task either!)
Rudi Fischer
"jim dorey" <sk...@ns.sympatico.ca> wrote
> not quite, it's more like the power rating is a
> clue to how much power
> can be put to it before distortion occurs.
wrecked for ever;-)
> Rudi Fischer wrote:
> > (And 'power-rating' != 'quality'!
!= means: 'is not equal'.
So?;-)
Regards
Bob Wilson
ke...@anasoft.co.uk says...
>
>Call me a fool then. I have been using that technique for well over 20
>years when choosing guitar speakers, and guess what. It works. There are
>invariable the loudest and sound great, usually.
Well, if your criteria for a good speaker are that it has to be "the
loudest" and "sound great", then I guess buying speakers by the pound is the
right way to go. Musical instrument speaker, in any event, are NOT
reproducers of sound. They are PROducers of sound, whose quirks are part of
the sound of the instrument. There is no connection between what is needed
for (say) a guitar amp speaker, and a quality stereo speaker. Connect any
guitar apeaker to a stereo ans see how bad it sounds!
>However, in practise, the weight of the magnet does still tell you quite a
lot
Yes, namely that this speaker weighs more than the other one.
>I think that you are not addressing the economic realities rather then the
>technical aspects of what makes a good speaker. If we assume that a decent
>manufacture uses say, non-ceramic magnets, they simply don't, in general,
>put heavier magnets on speakers if a smaller one will achieve the same aim.
>Its simple not cost effective.
Cheap. low flux ceramic magnets cost less than ceramic magnets with high
flux density. Because of this, a speaker that used a cheap magnet generally
needs a bigger (and heavier one), but that still can come out
cheaper, and sound poorer, than if better quality magnets were used. There
are lots of really high quality stereo speakers enclosures on the market
that use speakers with moderate (and optimally sized) magnets. Grossly
oversized magnets are, as I said, simply sucker-bait.
By the way, "sounding great" does not necessarily mean that the speaker is
any good. The majority of the population has no idea what an instrument is
SUPPOSED to sound like. Just because someone likes the sound of (say) a
speaker that grossly exaggerates mid-bass, does not make it a good speaker,
or at least a good reproducer, which is the benchmark of a good stereo
speaker. Some years ago, tests were made where listeners were allowed to add
distortion via a small hand-held control. They were told to adjust the
contro; until they got the the "best" sound. Almost no one found the best
setting was at the lowest point (where no distortion was added). The
majority felt that a setting that added a moderate level of harmonic
distorion was the optimum setting. Choosing a speaker simply becasue it has
a honkin' big magnet, "sounds great", and is "loudest", somehow doesn't come
as a big surprise.
Bob.
Kevin Aylward
> In article <XhId8.13023$H43.1...@news11-gui.server.ntli.net>,
> ke...@anasoft.co.uk says...
> >
>
> >Call me a fool then. I have been using that technique for well over 20
> >years when choosing guitar speakers, and guess what. It works. There are
> >invariable the loudest and sound great, usually.
>
> Well, if your criteria for a good speaker are that it has to be "the
> loudest" and "sound great", then I guess buying speakers by the pound is the
> right way to go. Musical instrument speaker, in any event, are NOT
> reproducers of sound. They are PROducers of sound, whose quirks are part of
> the sound of the instrument. There is no connection between what is needed
> for (say) a guitar amp speaker, and a quality stereo speaker. Connect any
> guitar apeaker to a stereo ans see how bad it sounds!
Put a decent dip in at around 600 Hz,and it cleans it up quite a bit:-)
> >However, in practise, the weight of the magnet does still tell you quite a
> lot
>
> Yes, namely that this speaker weighs more than the other one.
>
> >I think that you are not addressing the economic realities rather then the
> >technical aspects of what makes a good speaker. If we assume that a decent
> >manufacture uses say, non-ceramic magnets, they simply don't, in general,
> >put heavier magnets on speakers if a smaller one will achieve the same aim.
> >Its simple not cost effective.
>
> Cheap. low flux ceramic magnets cost less than ceramic magnets with high
> flux density. Because of this, a speaker that used a cheap magnet generally
> needs a bigger (and heavier one), but that still can come out
> cheaper, and sound poorer, than if better quality magnets were used. There
> are lots of really high quality stereo speakers enclosures on the market
> that use speakers with moderate (and optimally sized) magnets. Grossly
> oversized magnets are, as I said, simply sucker-bait.
>
I was not really considering ceramics. And it is obviously assumed that when one
is comparing things, one is comparing like things.
> By the way, "sounding great" does not necessarily mean that the speaker is
> any good. The majority of the population has no idea what an instrument is
> SUPPOSED to sound like. Just because someone likes the sound of (say) a
> speaker that grossly exaggerates mid-bass, does not make it a good speaker,
I know. Exaggerated mid bass usually sounds quite muffled. Really low bass with
high top on top is much better for me:-)
> or at least a good reproducer, which is the benchmark of a good stereo
> speaker. Some years ago, tests were made where listeners were allowed to add
> distortion via a small hand-held control. They were told to adjust the
> contro; until they got the the "best" sound. Almost no one found the best
> setting was at the lowest point (where no distortion was added). The
> majority felt that a setting that added a moderate level of harmonic
> distorion was the optimum setting.
This is all very well known. I posted on this quite recently. I like a tube amp
set "clean". Despite the fact that it will measure probably 1% THD or so, it
still sounds cleaner. There is a well known outboard effect called an "Aural
Exciter", by Digidesign. This adds selective harmonics and has been around for
over 20 years.
>Choosing a speaker simply becasue it has
> a honkin' big magnet, "sounds great", and is "loudest", somehow doesn't come
> as a big surprise.
>
>
Look, if one don't sound the loudest, the rhythm player will, and we can't have
that, no way.
JJ Richard
wrote:
I agree, Bob. Sound is subjective..no two ears are the same. However, Kevin is
correct, IMO, when he says that speaker X sounds better to him than speaker Y,
independent of the weight of the corresponding magnets. People who make buying
decisions solely based (or heavily weighed) upon magnet weight criteria are
being foolish (or, more accurately, fooled).
I think that the issue here should be focused more on what the OP *probably* had
in mind in the first place.
Speaker manufacturers and the salesmen who sell their products are modern day
snake oil peddlers...and many, if not most, of the manufacturers "pad the specs"
to appeal to "street mentality ". I'm certain that the corporate powers-that-be
are fully aware of the fact that street educated persons will scan the specs of
a speaker with magnet weight being a strong criteria in mind...and, of course,
salesmen couldn't be happier about it (either knowingly or unwittingly). After
all, what percentage of consumers have ever heard of the T/S specs?
Relatively few of us know better (magnet quality is the determining factor, not
magnet quantity), but we are in the minority. However, having lurked in this
group for years, I strongly suspect that Kevin is fully aware of this, and is
able to make the necessary distinctions therein.
What needs to be addressed, IMO, to a newbie asking questions on this topic is
to send them to links which will educate them on the matter...and perhaps
telling them to stay away from those large (Circuit City, et al) retailers when
seeking advice.
Perhaps sending them to more professional sites that deal with really high
quality components (JL Audio, etc), would prove more beneficial to them than
getting into debates over the permeations of flux capacitors... :)
Case in point...what should one say to a newbie who asks "Which is
better..ported or sealed? The guy at Circuit City said..."
The same goes for the age-old "monster cable", "gold plated RCA patch cords",
"tube vs. Xsistor", my daddy can beat up your daddy.....
Bottom line...educate the masses so that they are not fooled into spending big
bucks for nothing, but at the same time, temper that thinking with the fact that
reproduced audio quality is indeed subjective.
My two pennies,
JJ
Arch-lab
"JJ Richard" <JJRi...@mindspring.com> wrote in message
news:n73h7ug0dcscmpmcb...@4ax.com...
> On Sat, 23 Feb 2002 21:24:58 -0000, rfwi...@intergate.nospam.bc.ca (Bob
Wilson)
> wrote:
> My two pennies,
> JJ
>
>
>
>
>
>
>
>