There is a stage monitor I'm having problems with that uses this method.
The HF sounds very distorted and almost cuts in and out.
I looked closely inside and found some damaged push-on terminals. Ah, I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.
But no, the low level HF and distortion continued.
I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?
In the meantime I brought the HF driver home to check it's not voice
coil rub.
Graham
I just picked up a set of Bose (I know...they were cheap) 201s at a
thrift store. The only thing wrong with them--besides being Bose--were
the blown out protection lamps in series with the tweeters. Not bad for
$7.99, plus the cost of two lamps...altogether less than $10. They'll
make decent computer speakers for my 12 year old.
jak
jak
jakdedert wrote:
> Eeyore wrote:
> > This is a well established technique for preventing voice coils burning
> > out under conditions of 'overdrive'.
> >
> > There is a stage monitor I'm having problems with that uses this method.
> >
> > The HF sounds very distorted and almost cuts in and out.
> >
> > I looked closely inside and found some damaged push-on terminals. Ah, I
> > thought, probably a poor contact causing the probelm, replaced them,
> > checked driver DC resistances etc, reassembled thinking I'd probably
> > fixed it.
> >
> > But no, the low level HF and distortion continued.
> >
> > I'd checked the DC resistance of the protection bulb but later it
> > occurred to me that it might have 'very nearly' burnt out and have a
> > weak spot that wouldn't show up on a DVM but passing signal would heat
> > it and cause this trouble. I'll be able to find out soon enough but I
> > wondered if anyone else had ever encountered this ?
> >
> > In the meantime I brought the HF driver home to check it's not voice
> > coil rub.
>
> I imagine that there are variations in lamps, given that they are
> designed to provide 'light', not speaker protection. I suspect you'll
> find an issue with the driver, though. Swap them around to check and/or
> do a sweep test.
A 'swap', or rather replacement, was done earlier with no good effect. Hence I
laid the suspicion on the damaged push-ons. I will still test the drivers
though. I have 2 drivers that measure ok plus a third blown one and a
replacement diaphragm.
> I just picked up a set of Bose (I know...they were cheap) 201s at a
> thrift store. The only thing wrong with them--besides being Bose--were
> the blown out protection lamps in series with the tweeters. Not bad for
> $7.99, plus the cost of two lamps...altogether less than $10. They'll
> make decent computer speakers for my 12 year old.
Nice steal. For undemanding work they aren't *that* bad.
Graham
Bob Morein
(310) 237-6511
Some Machs and RCFs use a 24 volt projector lamp. I`ve seen these become
intermittent - they check fine with a meter, but introduce terrible
distortion and crackling under pressure - it sounds just like the driver
diaphragm breaking up. They also easily break if the cabinet is roughly
handled.
Ron
here is a novel thought
DON"T OVERDRIVE THEM
simple and effective
it's what I do
the easiest way to overdrive a speaker is to use a amp larger than the
speakers rateing
George
George
Soundhaspriority wrote:
> "Eeyore" <rabbitsfriend...@hotmail.com> wrote in message
>
> > This is a well established technique for preventing voice coils burning
> > out under conditions of 'overdrive'.
> >
> > There is a stage monitor I'm having problems with that uses this method.
> >
> > The HF sounds very distorted and almost cuts in and out.
> >
> > I looked closely inside and found some damaged push-on terminals. Ah, I
> > thought, probably a poor contact causing the probelm, replaced them,
> > checked driver DC resistances etc, reassembled thinking I'd probably
> > fixed it.
> >
> > But no, the low level HF and distortion continued.
> >
> > I'd checked the DC resistance of the protection bulb but later it
> > occurred to me that it might have 'very nearly' burnt out and have a
> > weak spot that wouldn't show up on a DVM but passing signal would heat
> > it and cause this trouble. I'll be able to find out soon enough but I
> > wondered if anyone else had ever encountered this ?
>
> I think it's unlikely, because any fracture causes a local hotspot, which
> rapidly leads to failure. I'd look at the socket instead! :)
I will double check that. Thanks for the tip.
> We've probably
> all seen strange tin-lead phenomena on lightbulb button contacts. The
> constant thermal cycling, the pressure, the dissimilar metals...
Interesting point.
Graham
Ron Johnson wrote:
> Eeyore wrote:
> > This is a well established technique for preventing voice coils burning
> > out under conditions of 'overdrive'.
> >
> > There is a stage monitor I'm having problems with that uses this method.
> >
> > The HF sounds very distorted and almost cuts in and out.
> >
> > I looked closely inside and found some damaged push-on terminals. Ah, I
> > thought, probably a poor contact causing the probelm, replaced them,
> > checked driver DC resistances etc, reassembled thinking I'd probably
> > fixed it.
> >
> > But no, the low level HF and distortion continued.
> >
> > I'd checked the DC resistance of the protection bulb but later it
> > occurred to me that it might have 'very nearly' burnt out and have a
> > weak spot that wouldn't show up on a DVM but passing signal would heat
> > it and cause this trouble. I'll be able to find out soon enough but I
> > wondered if anyone else had ever encountered this ?
> >
> > In the meantime I brought the HF driver home to check it's not voice
> > coil rub.
>
> Some Machs and RCFs use a 24 volt projector lamp.
24V truck lamp here.
> I`ve seen these become
> intermittent - they check fine with a meter, but introduce terrible
> distortion and crackling under pressure - it sounds just like the driver
> diaphragm breaking up.
That's EXACTLY what I'm getting. Thanks for the effective conformation.
> They also easily break if the cabinet is roughly handled.
Well it has been but the bulb's nicely cushioned.
Graham
George's Pro Sound Company wrote:
> "Ron Johnson" <r...@lunevalleyaudio.com> wrote
> > Eeyore wrote:
> >> This is a well established technique for preventing voice coils burning
> >> out under conditions of 'overdrive'.
>
> here is a novel thought
> DON"T OVERDRIVE THEM
> simple and effective
>
> it's what I do
> the easiest way to overdrive a speaker is to use a amp larger than the
> speakers rateing
The amps aren't but a blast of HF feedback will do it since it will whistle
through the HF filter. I am as it happens going to fit an 80W P-Audio driver
in the damn second JBL JRX112M that's blown its puny HF driver for the second
time, despite improving JBL's original ineffective bulb protection which was
100% ineffective. Jesus that design is CRAP. 1st order crossover !
Bear in mind these are the 15 year old monitors made of MDF and have been very
little trouble generally over the years.
Graham
or maybe it's time to upgrade from that MI grade junk your using
George
Meat Plow wrote:
> "George's Pro Sound Company"wrote:
> >"Meat Plow" <me...@petitmorte.net> wrote in message
> >> Eeyore wrote:
> >>
> >>>This is a well established technique for preventing voice coils burning
> >>>out under conditions of 'overdrive'.
> >>>
> >>>There is a stage monitor I'm having problems with that uses this method.
> >>>
> >>>The HF sounds very distorted and almost cuts in and out.
> >>>
> >>>I looked closely inside and found some damaged push-on terminals. Ah, I
> >>>thought, probably a poor contact causing the probelm, replaced them,
> >>>checked driver DC resistances etc, reassembled thinking I'd probably
> >>>fixed it.
> >>>
> >>>But no, the low level HF and distortion continued.
> >>>
> >>>I'd checked the DC resistance of the protection bulb but later it
> >>>occurred to me that it might have 'very nearly' burnt out and have a
> >>>weak spot that wouldn't show up on a DVM but passing signal would heat
> >>>it and cause this trouble. I'll be able to find out soon enough but I
> >>>wondered if anyone else had ever encountered this ?
> >>>
> >>>In the meantime I brought the HF driver home to check it's not voice
> >>>coil rub.
> >>
> >> Been using some Wharfedale stage gear for a year or so. The mains are
> >> all protected by lamps. I've replaced two in a year but not
> >> experienced a distorted HF. You'll find problems in the xover or drive
> >> I would assume rather than the lamp.
> >
> >or maybe it's time to upgrade from that MI grade junk your using
> >George
>
> Who, me?
From what I've heard they're well considered and in the IAG group now.
http://www.internationalaudiogroup.com/
The Chang brothers don't believe in messing about AIUI.
http://www.internationalaudiogroup.com/executive_summary.php
Graham
> "Ron Johnson" <r...@lunevalleyaudio.com> wrote in message
> news:LpudnR5cLpbJLYPU...@bt.com...
> > Eeyore wrote:
> >> This is a well established technique for preventing voice coils
> >> burning out under conditions of 'overdrive'.
> here is a novel thought
> DON"T OVERDRIVE THEM
> simple and effective
Easily said - but not so easy to do when setting up this sort of
equipment. Let alone when that equipment is being used by all sorts.
> it's what I do
> the easiest way to overdrive a speaker is to use a amp larger than the
> speakers rateing
Strangely that's not always so.
The best solution would be a decent limiter on the amp input - but these
cost if it's not going to sound horrid when it operates. A bulb is a very
cheap solution to help protect the speakers.
--
*If love is blind, why is lingerie so popular? *
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
again no lamps in my meyers, I do have alimiter but it is set well above
any threshold I pass music at.
why buy a 1000 watt amp then limit it to 300 watts, why not just buy a 300
watt amp?
George
I consider W home stereo grade gear, not suitable for Pro Live Sound, below
behringer
These days always having 'someone who knows what they're doing' is rare.
And even less likely with a small band starting out. So you need to make
equipment as idiot proof as possible.
> a amp equal to the speaker rms
> rateing will never burn out the speaker unless the amp is clipped hard
> and long it will never exceed the excursion of the speaker unless
> someone fires a gun a inch from a mic at foolish gains set your system
> up properly and you have no need for these foolish lamps.
Either the amp cannot produce enough wally to damage the speakers or it
can - so the gunshot thing is rubbish. But no speaker is designed to
handle DC for long - which is what you can get from a grossly overloaded
amp. To be certain that DC couldn't wreck the speakers would require a
*much* smaller amp than would otherwise make sense. Or, of course, use an
amp which can't pass DC.
> create cheap
> MI gear that is used improperly and you need to limit the abuse idiots
> can administer, to save on the warrentte costs I have never heard a
> speaker with lamps(I've owned plenty) sound as good as a speaker with
> out lamps
Correctly designed the lamp should have little effect on the sound as its
cold resistance will be very low. Only when it starts to 'protect' will
the resistance increase.
> again no lamps in my meyers, I do have alimiter but it is set well
> above any threshold I pass music at. why buy a 1000 watt amp then limit
> it to 300 watts, why not just buy a 300 watt amp?
Why are you using a limiter at all, then?
--
*Rehab is for quitters.
"Dave Plowman (News)" wrote:
> George's Pro Sound Company <bm...@yahoo.com> wrote:
> > "Ron Johnson" <r...@lunevalleyaudio.com> wrote in message
> > > Eeyore wrote:
> >
> > >> This is a well established technique for preventing voice coils
> > >> burning out under conditions of 'overdrive'.
>
> > here is a novel thought
> > DON"T OVERDRIVE THEM
> > simple and effective
>
> Easily said - but not so easy to do when setting up this sort of
> equipment. Let alone when that equipment is being used by all sorts.
And it is. Another new house engineer recently for example.
> > it's what I do the easiest way to overdrive a speaker is to use a amp
> larger than the
> > speakers rateing
>
> Strangely that's not always so.
Well this is where it gets slightly complicated.
> The best solution would be a decent limiter on the amp input - but these
> cost if it's not going to sound horrid when it operates. A bulb is a very
> cheap solution to help protect the speakers.
But a simple level limiter still won't stop the amp delivering full power say
@ 8kHz. Tweeters aren't meant to see that. It would have to be a frequency
sensitive limiter matched to the crossover. Which has given me a product idea
of course.
Graham
Actually, the easiest way to overdrive a speaker is to play it at a level
where it produces audible distortion. But as most listeners have no idea
what distortion sounds like...
Bullshit
excursion aand burning out are completely diffrent
a amp "can" put out several times it's rated power for a instant, enough to
throw a cone. been there already
But no speaker is designed to
> handle DC for long - which is what you can get from a grossly overloaded
> amp. To be certain that DC couldn't wreck the speakers would require a
> *much* smaller amp than would otherwise make sense.
the lamp does nothing twards DC protection. I have caps on my tweeters that
do prevent DC
Or, of course, use an
> amp which can't pass DC.
except when they fail.
>
>> create cheap
>> MI gear that is used improperly and you need to limit the abuse idiots
>> can administer, to save on the warrentte costs I have never heard a
>> speaker with lamps(I've owned plenty) sound as good as a speaker with
>> out lamps
>
> Correctly designed the lamp should have little effect on the sound as its
> cold resistance will be very low. Only when it starts to 'protect' will
> the resistance increase.
the designers activate these lamps at such low power levels they are almost
constantly lit
>
>> again no lamps in my meyers, I do have alimiter but it is set well
>> above any threshold I pass music at. why buy a 1000 watt amp then limit
>> it to 300 watts, why not just buy a 300 watt amp?
>
> Why are you using a limiter at all, then?
why not properly use a properly sized amp, why would you limit within the
range that your produceing in?
if it ain't loud enough, deploy more gear.
I have limiters for dumb fucks
true story from 1993 at one of my first shows with a guest engineer
like the guy who's talkback mic was draped across my console when he grabbed
it the cable spun the trim pot for the kick drum to max
next hit of the drum I had 7 18 inch speaker cones sitting in the feild
next day I got a limiter
more true lifes adventures
for when the "talent" throws a wireless mic against the wall, but the
limiter didn't stop Marlyn Manson from trashing a Midas console on me with a
cast base mic stand though
george
thats why I don't take direction from the audience
George
>
>
OTOH distortion does not destroy speakers, speakers are as happy to play
distortion as clean signal
only when you exceed the heat dissipating ability of the motor do you burn
out a speaker
clipping does not damage speakers and distortion does not damage speakers,
its overheating and over excursion that damages speakers
distortion is one method of achieving overheating, but you can overheat with
a spotlessly clean signal as well
>
>
>>> the easiest way to overdrive a speaker is to use a[n] amp
>>> larger than the speaker[']s rateing [sic]
>> Actually, the easiest way to overdrive a speaker is to play it at a level
>> where it produces audible distortion. But as most listeners have no idea
>> what distortion sounds like...
> OTOH distortion does not destroy speakers, speakers are as happy to play
> distortion as clean signal only when you exceed the heat dissipating
ability
> of the motor do you burn out a speaker
Although what you say is true in terms of physics (the speaker's excursion
limits do not have a necessary relationship with its heat-dissipating
capability), in practice, audible distortion is a warning that you should
turn down the volume. William Michael Watson Dayton-Wright told me horror
stories of how he could not design a speaker with sufficient power-handling
capability to keep "deaf" listeners from overdriving and damaging it.
> clipping does not damage speakers and distortion does not damage
> speakers, it[']s overheating and over excursion that damages speakers
> distortion is one method of achieving overheating, but you can overheat
> with a spotlessly clean signal as well
The distortion I was talking about was the sort that comes from pushing it
into its excursion limits.
I grant you all your points as valid, and bottoming(or farting) a woofer is
truely a horid sound
George
>
>
Agreed. I've never heard it called that, but it's an apt description.
What gets you up so early on a Sunday? (I'm on the west coast, and have been
up since 2AM.)
went out had a couple of dogfish 90 minutes and that set me down early(8pm)
some days your just not tired at 4 am
G
>
>
> went out had a couple of dogfish 90 minutes and that set me down
> early(8pm) some days your just not tired at 4 am
As in...
http://www.dogfish.com/brewings/Seasonal_Beers/Punkin_Ale/3/index.htm
But an interesting twist is that with the simple 2nd order HPFs I have been trying (with a
very high Fc, eg 8 kHz, to flatten CD horn response and match sensitivities), a lamp or
polyswitch in the INPUT to the crossover has the nice benefit of also seeing more MF, and
so potentially account for both thermal and displacement limitations. Admittedly the time
constants cannot be independent as would really be required, but it's still better than
having the lamp in the crossover output circuit, and a LOT safer for the amp, which
becomes UNLOADED when the protection operates, instead of shorted.
Tony
"Eeysore = incorrigible pommy fuckwit TROLL "
>> ** QUIT the fucking CROSS POSTING
>>
>> ARSEHOLE !!!!
>>
>> >The cross-posting was to relevant groups you clown.
>>
>> ** Those other NGs are NOT compatible with this one.
>
> Yes they are.
** 100% WRONG.
Your autism is showing - big time.
CROSSPOSTING IS AN ABOMINATION !!
Stevenson is the BIGGEST TROLL on Usenet
.... Phil
Jeez...a little knowledge is a dangerous thing.
Suggest you try driving a DC coupled amp into heavy clipping and see the
results to speakers which can nominally handle its output.
--
*A 'jiffy' is an actual unit of time for 1/100th of a second.
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Really?, I'll make sure I don't do business with you.
Btw, distortion due to amplifier saturation, even though the amp is
far belong the rating of the speaker can and does over heat the speaker
coil and thus, can terminate the life of a speaker even rated higher
than said amp.
I'll say no more.
http://webpages.charter.net/jamie_5"
you don't have to
you already stated it was the HEAT that killed the speaker
the distortion was just a means to generate the heat
put a 100% distored signal from a 1 watt amp into a 600 watt woofer and you
will not live long enough to see it burn out.
its NOT the distortion, it's the HEAT
Distortion is simply one way to obtain heat, so is a blow torch and so is a
clean signal with too many watts behind it
it's not the jumping off the bridge that kills you, it's the impact with the
ground
do you understand?
George
No, it isn't. You are cross posting to these groups:
news:rec.audio.tech
news:alt.audio.pro.live-sound
news:sci.electronics.repair
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
> you don't have to you already stated it was the HEAT that killed the
> speaker the distortion was just a means to generate the heat put a 100%
> distored signal from a 1 watt amp into a 600 watt woofer and you will
> not live long enough to see it burn out. its NOT the distortion, it's
> the HEAT Distortion is simply one way to obtain heat, so is a blow torch
> and so is a clean signal with too many watts behind it
So a 1 watt power amp and 600 watt speakers is your formula to prevent
speaker damage under all conditions?
You must have very large arms.
> "Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
> news:4fff306...@davenoise.co.uk...
> > In article <gfpb2i$us8$1...@aioe.org>, liquidator
> > <mi...@mad.scientist.com> wrote:
> >
> >> "Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
> >> news:4fff15e...@davenoise.co.uk...
> >> > But no speaker is designed to handle DC for long - which is what
> >> > you can get from a grossly overloaded amp. To be certain that DC
> >> > couldn't wreck the speakers would require a *much* smaller amp than
> >> > would otherwise make sense. Or, of course, use an amp which can't
> >> > pass DC.
> >> >
> >
> >> Jeez...a little knowledge is a dangerous thing.
> >
> > Suggest you try driving a DC coupled amp into heavy clipping and see
> > the results to speakers which can nominally handle its output.
> >
> and to what point is this abuse of equipment warrented? should I trow my
> cabinets off tall building to prove that they will be destroyed? this is
> the PRO LIVE SOUND newsgroup we do not drive ANY amps into heavy
> clipping, for any reason what-so-ever George
Err, then why are you crossposting to other groups?
However doesn't 'your' group get read by equipment hirers etc?
And to suggest no pro equipment ever gets abused by pros is pie in the
sky...
--
*To be intoxicated is to feel sophisticated, but not be able to say it.
You would have flunked electronics 101.
Clipping and DC are not the same thing. That argument was selltled years
ago- only those with minimal knowledge advance it today.
BTW have driben amps to clipping on the bench hundreds of times in the last
40+ years.
Your problem is you are trying to talk down to somebody who knows a lot more
than you.
Go learn enough to argue then come back..
> "Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
> news:4fff306...@davenoise.co.uk...
>
>>In article <gfpb2i$us8$1...@aioe.org>,
>> liquidator <mi...@mad.scientist.com> wrote:
>>
>>
>>>"Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
>>>news:4fff15e...@davenoise.co.uk...
>>>
>>>> But no speaker is designed to handle DC for long - which is what you
>>>>can get from a grossly overloaded amp. To be certain that DC couldn't
>>>>wreck the speakers would require a *much* smaller amp than would
>>>>otherwise make sense. Or, of course, use an amp which can't pass DC.
>>>>
>>
>>>Jeez...a little knowledge is a dangerous thing.
>>
>>Suggest you try driving a DC coupled amp into heavy clipping and see the
>>results to speakers which can nominally handle its output.
>>
>
>
> You would have flunked electronics 101.
>
> Clipping and DC are not the same thing. That argument was selltled years
> ago- only those with minimal knowledge advance it today.
>
> BTW have driben amps to clipping on the bench hundreds of times in the last
> 40+ years.
>
> Your problem is you are trying to talk down to somebody who knows a lot more
> than you.
>
> Go learn enough to argue then come back..
>
>
Any one have some hip boots ? my normal boots aren't tall enough!
Ahnothetr person with minimal knowledge.
George doesn't always word things the best way, but he knows a lot.
Speakers are rated for average power, over time.
Look at the area under a square wave- it is a lot larger than the area under
a sine wave. What that means is more power for a longer time. What is
happening is the AMOUNT of power is being increased to a speaker for a
longer TIME.
Plain and simple- that is more power. It is the amout of power over time
that kills the speaker...it can only shed heat so fast, put power in faster
than that it will burn up.
Simple..just use a bigger amp...and drive it to peak, you can blow the
speaker quickly.
Use a smaller amp, and drive it to its full power for longer, and the
speaker will blow, assuming the amp is big enough to put out that much
average power.
Either way- it is power that is the culprit. The amount of energy being put
into the speaker...put it in faster than the speaker can sink it, you will
have thermal failure.
It is not DC as people who skimmed one book and didn't understand it want to
insist.
Make the amp small enough, the speaker can handle any waveform. Make the amp
big enough and the speaker will fail instantly with any input at all...then
there are a million scenarios in between.
I disagreee with George, I use big amps and don't blow speaker, conversely
people are blowing their 100 watt speakers with "50 watt" amplifiers.
Take a look at an EV speaker rating...xxx watss with pink noise for xxx
hours.
Change the signal, the speaker's rating changes. Incraes the time, the
speaker's rating changes.
Square waves or severe clipping is more power for a longer time. That is all
it is.
Not DC, not any big mystery, it's a measurable phenomenon.
I do agree with George that sizing amps and sopeakers reduces chance for
failure. But many touring companies use big amps for horns also, larger amps
tend to hold their resale better, from a business standpoint make more sense
to me.
Here's a semi pro example-
Loot at the price difference between a Behringer 2500 and a 1500. Not
much...but come resale time you will do a lot better with the 2500..
Business is business, I buy bigger amps. your mileage may vary.
Jeez- another idiot to killfiter- where are you pointing out what I said was
wrong?
No where- simply because you don't know enough.
Dave we've gooten off on the wrong foot, but what happens is Eeyore starts
these damn crossposts.
He has been asked a number of times to stop.
He's a nice fellow but he keeps staring into space and mumbling
"crossposting is good".
What it does is throw groups of people together who don't know each
other...it ALWAYS wstarts fights .PERIOD.
I wish Graham (Eeyore) would stops as he's been asked to- but he's convinced
he's right, and no amount of logic is gonna change that..
What ever you do think you know as fact, must of come at a great expense
of destroying a lot of electronics.
> You would have flunked electronics 101.
> Clipping and DC are not the same thing. That argument was selltled years
> ago- only those with minimal knowledge advance it today.
> BTW have driben amps to clipping on the bench hundreds of times in the
> last 40+ years.
> Your problem is you are trying to talk down to somebody who knows a lot
> more than you.
Pot, kettle.
HTH.
--
*I'm not your type. I'm not inflatable.
You are right of course, I outgrew Little League decades ago.
Later, Junior.
Again showing your gross ignorance.
As a working pro I'm sure I paid more in taxes than you earned.
Welcome to the killfiles as the only total loss I've seen today.
Dont' bother replying, but your juvenile need to will make you do it anyway.
"Dave Plowman (News)" wrote:
> George's Pro Sound Company <bm...@yahoo.com> wrote:
> > "Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
> > > George's Pro Sound Company <bm...@yahoo.com> wrote:
> > >> "Ron Johnson" <r...@lunevalleyaudio.com> wrote in message
> > >> > Eeyore wrote:
> > >>
> > >> >> This is a well established technique for preventing voice coils
> > >> >> burning out under conditions of 'overdrive'.
> > >
> > >> here is a novel thought
> > >> DON"T OVERDRIVE THEM
> > >> simple and effective
> > >
> > > Easily said - but not so easy to do when setting up this sort of
> > > equipment. Let alone when that equipment is being used by all sorts.
> > >
> > >> it's what I do the easiest way to overdrive a speaker is to use a amp
> larger than the
> > >> speakers rateing
Doesn't stop the amp having greater than the HF driver's rating !
> > > Strangely that's not always so.
> > >
> > > The best solution would be a decent limiter on the amp input - but
> > > these cost if it's not going to sound horrid when it operates. A bulb
> > > is a very cheap solution to help protect the speakers.
> > >
> > No lamps in my meyers. setting up a system that both sounds good and
> > stays within the limits of the equipment used is NOT hard, it simply
> > requires one know what they are doing.
>
> These days always having 'someone who knows what they're doing' is rare.
> And even less likely with a small band starting out. So you need to make
> equipment as idiot proof as possible.
>
> > a amp equal to the speaker rms
> > rateing will never burn out the speaker unless the amp is clipped hard
> > and long it will never exceed the excursion of the speaker unless
> > someone fires a gun a inch from a mic at foolish gains set your system
> > up properly and you have no need for these foolish lamps.
>
> Either the amp cannot produce enough wally to damage the speakers or it
> can - so the gunshot thing is rubbish. But no speaker is designed to
> handle DC for long - which is what you can get from a grossly overloaded
> amp. To be certain that DC couldn't wreck the speakers would require a
> *much* smaller amp than would otherwise make sense. Or, of course, use an
> amp which can't pass DC.
Or ensure the amp you have is fitted with DC 'crowbar' protection such as I
design in.. Or output relays but these can oxidise their contacts degrading the
sound, and if they don't have enough clearance will arc-over on a DC fault.
> > create cheap
> > MI gear that is used improperly and you need to limit the abuse idiots
> > can administer, to save on the warrentte costs I have never heard a
> > speaker with lamps(I've owned plenty) sound as good as a speaker with
> > out lamps
>
> Correctly designed the lamp should have little effect on the sound as its
> cold resistance will be very low. Only when it starts to 'protect' will
> the resistance increase.
>
> > again no lamps in my meyers, I do have alimiter but it is set well
> > above any threshold I pass music at. why buy a 1000 watt amp then limit
> > it to 300 watts, why not just buy a 300 watt amp?
>
> Why are you using a limiter at all, then?
I think you summed it up pretty well there Dave.
Graham
William Sommerwerck wrote:
> > the easiest way to overdrive a speaker is to use a[n] amp
> > larger than the speaker[']s rateing [sic]
>
> Actually, the easiest way to overdrive a speaker is to play it at a level
> where it produces audible distortion. But as most listeners have no idea
> what distortion sounds like...
Exceed X max (not difficult with ported cabs) and you can do a lot of damage
to the LF driver too.
Graham
George's Pro Sound Company wrote:
> a amp "can" put out several times it's rated power for a instant, enough to
> throw a cone. been there already
UTTER and complete rubbish. If you're referring to the difference between an rms
and peak voltage or power, that's already taken into account in the speaker's
rating. Yes, you can get a bit more out of an amp on toneburst but rarely much
over 1-2dB at the very most. Certainly not for long enough to do any damage.
You're straying into tech territory here George that you don't understand. Stick
to rigging and mixing.
Graham
George's Pro Sound Company wrote:
> "William Sommerwerck" <grizzle...@comcast.net> wrote in message
>
> >> the easiest way to overdrive a speaker is to use a[n] amp
> >> larger than the speaker[']s rateing [sic]
> >
> > Actually, the easiest way to overdrive a speaker is to play it at a level
> > where it produces audible distortion. But as most listeners have no idea
> > what distortion sounds like...
>
> OTOH distortion does not destroy speakers, speakers are as happy to play
> distortion as clean signal
> only when you exceed the heat dissipating ability of the motor do you burn
> out a speaker
Generally. But not exclusively by far.
Exceeding X max can trash an LF or HF driver without as much as even a
discoloured voice coil. And there are many easy ways to do it.
Graham
William Sommerwerck wrote:
> in practice, audible distortion is a warning that you should
> turn down the volume.
Couldn't agree more.
> The distortion I was talking about was the sort that comes from pushing it
> into its excursion limits.
(X max)
Precisely. I have a lovely pair of Altec diaphragms in my "rogue's gallery" that
demonstrates this perfectly. The voice coils meaure 100% OK and look OK.
Graham
George's Pro Sound Company wrote:
> bottoming(or farting) a woofer is truely a horid sound
That's technically exceeding X max (Thiele and Small parameters). Easy to do
with ported cabs and no suitable high order HPF.
Mine (my client's) is 24dB/octave @ 35Hz.
Graham
Behringer is like any company...some usable for semi pro, some absolute
garbage.
Thee odd thing is most negative comments about Behringer do NOT come from
users as you say.
Almost all negative posts about Behringer are from users of other brands.
It's no worse than any other cheap stuff, better sometimes. I don't us it,
but plenty of weekend warrriors do.
If Behringer was a s bad as people try to say, they would be out of
business.
Conclusion- many aof the negative posts are bull.
I don't use Behringer, or Mackie, or any of that kinda stuff. But I am not
gonna insist everybody drive the same brand of car I do.
George's Pro Sound Company wrote:
> "William Sommerwerck" <grizzle...@comcast.net> wrote
>
> >>> What gets you up so early on a Sunday? (I'm on the west coast,
> >>> and have been up since 2AM.)
> >
> >> went out had a couple of dogfish 90 minutes and that set me down
> >> early(8pm) some days your just not tired at 4 am
> >
> > As in...
> >
> > http://www.dogfish.com/brewings/Seasonal_Beers/Punkin_Ale/3/index.htm
> >
> Same brewery but this IPA
> http://www.dogfish.com/brewings/Year_Round_Beers/90_Minute_IPA/11/index.htm
Are you familiar with the origin of the name 'IPA' ?
Graham
Tony wrote:
> I like to protect gear from whatever might come, so I like lamps and polyswiches. I would
> be almost as happy with a frequency-selective limiter that could independently account for
> the thermal and displacement limits of the tweeter, mid and woofer (with appropriately
> different time constants - an even greater challenge), but the reality is that a lamp in
> the tweeter circuit handles 80% of abuse, so it's cheap insurance.
That's how I see it too. We don't get many lamps blown but it does happen, even in the EV
QRx's (almost once a year on average).
> But an interesting twist is that with the simple 2nd order HPFs I have been trying (with a
> very high Fc, eg 8 kHz, to flatten CD horn response and match sensitivities), a lamp or
> polyswitch in the INPUT to the crossover has the nice benefit of also seeing more MF, and
> so potentially account for both thermal and displacement limitations. Admittedly the time
> constants cannot be independent as would really be required, but it's still better than
> having the lamp in the crossover output circuit, and a LOT safer for the amp, which
> becomes UNLOADED when the protection operates, instead of shorted.
Indeed it should ALWAYS be on the input side. Which is how ours are arranged. It just
disconnects the HPF.
Graham
"Dave Plowman (News)" wrote:
> liquidator <mi...@mad.scientist.com> wrote:
> > "Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
> >
> > > But no speaker is designed to handle DC for long - which is what you
> > > can get from a grossly overloaded amp. To be certain that DC couldn't
> > > wreck the speakers would require a *much* smaller amp than would
> > > otherwise make sense. Or, of course, use an amp which can't pass DC.
>
> > Jeez...a little knowledge is a dangerous thing.
>
> Suggest you try driving a DC coupled amp into heavy clipping and see the
> results to speakers which can nominally handle its output.
That's why I use 'clip eliminator circuits'. Did my first 18 years ago in the
1200B. Used a transconductance amp in a feedback loop (inactive until clip
sensed so no effect on normal signal).
Graham
George's Pro Sound Company wrote:
> put a 100% distored signal from a 1 watt amp into a 600 watt woofer and you
> will not live long enough to see it burn out.
Uh ?
A 100% distorted signal would be a square wave of 2W rating. That's not going to
bother ANY 600W rated voice coil.
Graham
"Michael A. Terrell" wrote:
> George's Pro Sound Company wrote:
> >
> > this is the PRO LIVE SOUND newsgroup
>
> No, it isn't. You are cross posting to these groups:
>
> news:rec.audio.tech
> news:alt.audio.pro.live-sound
> news:sci.electronics.repair
More correctly I was, since the original question was relevant to all.
George should have trimmed the groups for pro-sound comments only.
Graham
"Michael A. Terrell" wrote:
> George's Pro Sound Company wrote:
> >
> > this is the PRO LIVE SOUND newsgroup
>
> No, it isn't. You are cross posting to these groups:
>
> news:rec.audio.tech
> news:alt.audio.pro.live-sound
> news:sci.electronics.repair
In practice, I think you'll find the subject matter is still of interest in
all of these.
Graham
"Dave Plowman (News)" wrote:
> And to suggest no pro equipment ever gets abused by pros is pie in the
> sky...
Many a JBL D150 went to meet its maker in the 70s. In flames quite often.
Graham
liquidator wrote:
> "Jamie" <jamie_ka1lpa_not_v...@charter.net> wrote in message
> > >
> > Any one have some hip boots ? my normal boots aren't tall enough!
>
> Jeez- another idiot to killfiter- where are you pointing out what I said was
> wrong?
Jamie is notorious (with me at least) for having some very odd ideas sometimes
in the electronics groups. I think he's a little bit out of touch with current
practice in this area.
Graham
liquidator wrote:
> Dave we've gooten off on the wrong foot, but what happens is Eeyore starts
> these damn crossposts.
>
> He has been asked a number of times to stop.
>
> He's a nice fellow but he keeps staring into space and mumbling
> "crossposting is good".
>
> What it does is throw groups of people together who don't know each
> other...it ALWAYS wstarts fights .PERIOD.
>
> I wish Graham (Eeyore) would stops as he's been asked to- but he's convinced
> he's right, and no amount of logic is gonna change that..
According to the currently accepted rules of netquette, a post that is relevant
to several groups SHOULD be cross-posted. Most certainly not multiposted.
Explain how it is off-charter in rec.audio.tech or sci.electronics.repair where
a lot of audio is discussed daily. It was a repair question after all ! And
technical.
Graham
Jamie wrote:
> Boy!, you're way out of your league..
Typical Jamie response.
Liquidator knows his stuff 99+ odd % of the time.
Graham
Meat Plow wrote:
> "George's Pro Sound Company" wrote:
> >"Meat Plow" <me...@petitmorte.net> wrote in message
> >>
> >> I wouldn't call Wharfedale junk. It's usable, sounds good and reliable
> >> and a lot less expensive than other name brands.
> >
> >I consider W home stereo grade gear, not suitable for Pro Live Sound, below
> >behringer
>
> Glad to hear it. I don't suppose you're a musician who uses Wharfe
> gear or repairs pro audio gear for a living, but rather just another
> consumer or retailer who has an opinion.
He's a US (NY state AIUI) audio hire company operator.
> As far as the Behringer gear goes I have no experience with it so
> other than seeing a lot of negative comments about it from those who
> do use or repair it I have no opinion.
Seen and heard of more Behringer gear die prematurely than any other brand that
one ought presumably to be able to take seriously.
Ron (UK) tried 2 of their big amps. Both went U/S just outside warranty.
OTOH, the venue I help out still has 2 of my Studiomaster D series amps working
day in, day out and both are 10+ yrs old. Only maintence needed, blowing out the
heatsinks and replacing a couple of scratchy gain pots. And you can replace those
pots in 15 mins compared to the over one HOUR it takes for a QSC RMX !
Graham
liquidator wrote:
> Thee odd thing is most negative comments about Behringer do NOT come from
> users as you say.
I've experienced their stuff fail on one of my clients. He will NOT buy
Behringer any more. He has a BUSINESS to run that requires RELIABILITY.
Graham
liquidator wrote:
> "Dave Plowman (News)" <da...@davenoise.co.uk> wrote
> >
> > Suggest you try driving a DC coupled amp into heavy clipping and see the
> > results to speakers which can nominally handle its output.
>
> You would have flunked electronics 101.
>
> Clipping and DC are not the same thing. That argument was selltled years
> ago- only those with minimal knowledge advance it today.
In the early days of DC coupled outputs, some amps still had a degree of
internal AC coupling or bypassing in the drive circuitry.
They could indeed 'drift' DC under prolonged overdrive.
Graham
my opionons are formed by the gear I choose to own or not own, I IN FACT put
my money where my mouth is
I OWN a sr company with a 1/4 million dollars of inventory and events that
have run into the 100,000 attendence range
be at it over 20 years
I feature mostly Meyer Sound Labs gear for the serious rig and behringer for
the disposable low end crap
George
liquidator wrote:
> "Jamie" wrote in message
> >
> > Btw, distortion due to amplifier saturation,
What is this "amplifier saturation" you talk of ? Please use accepted
terminology.
> > even though the amp is
> > far belong the rating of the speaker can and does over heat the speaker
> > coil and thus, can terminate the life of a speaker even rated higher
> > than said amp.
>
> Ahnothetr person with minimal knowledge.
This is my experience of Jamie too. He reckons he's some hot shot but constantly
uses the wrong words to describe things for example. His knowledge is also very
dated.
Graham
George's Pro Sound Company wrote:
> I feature mostly Meyer Sound Labs gear for the serious rig and behringer for
> the disposable low end crap
I'd love to lnow if Behringer gear destined for the N.A. market still uses
leaded solder. Could exaplin a LOT ! Any chance of asking Jim Savery. I've lost
his contact details.
Graham
>>> Glad to hear it. I don't suppose you're a musician who uses Wharfe
>>> gear or repairs pro audio gear for a living, but rather just another
>>> consumer or retailer who has an opinion.
>>>
>>> As far as the Behringer gear goes I have no experience with it so
>>> other than seeing a lot of negative comments about it from those who
>>> do use or repair it i have no opinion.
>>
>>my opionons are formed by the gear I choose to own or not own, I IN FACT
>>put
>>my money where my mouth is
>>I OWN a sr company with a 1/4 million dollars of inventory and events that
>>have run into the 100,000 attendence range
>>be at it over 20 years
>>I feature mostly Meyer Sound Labs gear for the serious rig and behringer
>>for
>>the disposable low end crap
>>George
>>
>
> LOL!
?????????
George
Graham, you play with toys.. you work with toys.. and as usual,
all you have left is finger pointing because you've lost what ever
you had. That is, if you had anything of value to start with other
than what you find off the backs of others.
Your knowledge of electronics is most likely gained from destroying
an untold amount of components and still to this day, you have to
scratch that bold head of yours and wonder what you did with that last
puff of smoke you allowed to escape.
You boast that your an elite in audio design, from what I've seen you
point out. A mear amateur, expert you are not!.
Thank you and have a nice day, BSA..
It's not shocking that you would side with him. If I
didn't know any better, the two of you must be collaborating.
It would explain a lot of things.
Graham, the hole your digging is getting bigger.
Please watch your step, I wouldn't want to see any one get
hurt now.
You are not an elite in audio design or any other for that fact,
get over your self. I'm sure you're good for something and maybe
one day you'll find it.
LOL, yes, I must say you're correct in this statement..
Because, if you are one that dictates current practices, I
feel sorry for the rest that follows your guide lines! oh
wait, that can never happen. You just simply spit out crap
and never give any useful information that can be used in real life
applications.
You just go on, boasting your fantasy story's..
is there anything you haven't done or don't know?
I know your an old fart and most likely starting to get
senile.
> "Jamie" <jamie_ka1lpa_not_v...@charter.net> wrote in message
> news:IeZTk.199$%O2....@newsfe20.iad...
>
>>liquidator wrote:
>>
>>
>>>"Jamie" <jamie_ka1lpa_not_v...@charter.net> wrote in
>
> message
>
>>>news:pcXTk.5083$ev2....@newsfe12.iad...
>>>
>>>
>>>>George's Pro Sound Company wrote:
>>>>
>>>>
>>>>
>>>>>"William Sommerwerck" <grizzle...@comcast.net> wrote in message
>>>>>news:gfp0ol$f7q$1...@news.motzarella.org...
>>>>>
>>>>>
>>>>>
>>>>>>>the easiest way to overdrive a speaker is to use a[n] amp
>>>>>>>larger than the speaker[']s rateing [sic]
>>>>>>
>>>>>>Actually, the easiest way to overdrive a speaker is to play it at a
>>>
>>>level
>>>
>>>
>>>>>>where it produces audible distortion. But as most listeners have no
>
> idea
>
>>>>>>what distortion sounds like...
>>>>>
>>>>>
>>>>>OTOH distortion does not destroy speakers, speakers are as happy to
>
> play
>
>>>>>distortion as clean signal
>>>>>only when you exceed the heat dissipating ability of the motor do you
>>>
>>>burn
>>>
>>>
>>>>>out a speaker
>>>>>
>>>>>clipping does not damage speakers and distortion does not damage
>>>
>>>speakers,
>>>
>>>
>>>>>its overheating and over excursion that damages speakers
>>>>>distortion is one method of achieving overheating, but you can overheat
>>>
>>>with
>>>
>>>
>>>>>a spotlessly clean signal as well
>>>>>
>>>>>
>>>>>
>>>>
>>>>Really?, I'll make sure I don't do business with you.
>>>>
>>>> Btw, distortion due to amplifier saturation, even though the amp is
>>>>far belong the rating of the speaker can and does over heat the speaker
>>>>coil and thus, can terminate the life of a speaker even rated higher
>>>>than said amp.
>>>
>>>
>>>
>>>Ahnothetr person with minimal knowledge.
>>>
> Again showing your gross ignorance.
> As a working pro I'm sure I paid more in taxes than you earned.
>
> Welcome to the killfiles as the only total loss I've seen today.
>
> Dont' bother replying, but your juvenile need to will make you do it anyway.
>
>
Thank you very much, and don't worry, my kill file is full of idiots
like you.
P.S.
No one person is over anyone else. Just remember, every one
can be replaced with better than what you think you are.
It's not against the law to fart in an elevator- just because you CAN do
something is it a good idea?
% out of 5 of your last crossposts have started arguments.
It appears to matter not to you. one can only assume you enjoy the
arguments.
Graham, you know I don't have anything against you. But what happens when
there is a disagreement between people in two different groups is that
persons friends join in, often they don't even understand the discussion,
they are just PO'd somebody is dissing their friiend...such arguments can't
be one by anybody, and anybody who posts more than 3 times to them has way
too much time on their hands. But Usenet is full of people with too much
time on their hands. And too little knowledge.
Voltage and resistance practice too.As well as theory.
Since you insist on groaner puns....
Ghandi of cousre, was an Indian holy man. What is not know as much is he had
to walk everywhere, consequently building up heavy callouses on his feet.
Due to poor diet, he suffered constant ill health and bad breath.
He was a super calloused fragile mystic vexed by halitosis.
I hope that settles the matter.
You are spot on with that condition...but I assumed that we would be talking
about "current" amps.
I wouldn't be using any of those old amps on the job.
Curious- India Pale? No I'd be interested in where the term came from...I
knew the gin and tonic came from having to drink quinine against malaria.
extra hops were added to the beer going from Great Britain to India as a
preservative
hence India Pale Ale, the pale ale bound for India
so a IPA is a hoppier Pale ale
and a double IPA is Hoppier, Imperial Pales are also sometimes called double
IPA's
George
>
>
Drive an amp hard enough and that's what you effectively get, as far as
the speaker is concerned. Try taking your head out of your arse and use
that scope.
--
*Time is the best teacher; unfortunately it kills all its students.
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Ignorance is bliss and you are happy the way you are.
Simply, you are just plain wrong. You seem to be interested in making
yourself look worse and worse, go on about it with somebody else please.
You've sufficiently proven it to me.
Clipping isn't DC, obvious you never studied engineering. Or physics. Or
much else, it looks like.
Bye. No more time for you. Got real things to do.
Jamie wrote:
> Eeyore wrote:
> > liquidator wrote:
> >>"Jamie" wrote in message
> >>
> >>> Btw, distortion due to amplifier saturation,
> >
> > What is this "amplifier saturation" you talk of ? Please use accepted
> > terminology.
> >
> >>>even though the amp is
> >>>far belong the rating of the speaker can and does over heat the speaker
> >>>coil and thus, can terminate the life of a speaker even rated higher
> >>>than said amp.
> >>
> >>Ahnothetr person with minimal knowledge.
> >
> > This is my experience of Jamie too. He reckons he's some hot shot but constantly
> > uses the wrong words to describe things for example. His knowledge is also very
> > dated.
>
> Graham, you play with toys.. you work with toys.. and as usual,
> all you have left is finger pointing because you've lost what ever
> you had. That is, if you had anything of value to start with other
> than what you find off the backs of others.
>
> Your knowledge of electronics is most likely gained from destroying
> an untold amount of components and still to this day, you have to
> scratch that bold head of yours and wonder what you did with that last
> puff of smoke you allowed to escape.
>
> You boast that your an elite in audio design, from what I've seen you
> point out. A mear amateur, expert you are not!.
Answer the bloody question IDIOT !
What is a "saturated amplifier" ? You can't even use the right words.
Graham
Jamie wrote:
> Graham, the hole your digging is getting bigger.
IGNORANT PRICK