Speaker Damage | Burnt Drivers

Post by n***@gmail.com
Hi Folks,
Hope all is well.
Please can I pick your brains for a moment?!
How would it be possible to damaged/burn out 4x bass/mid driver units, in 4x separate cabinets, >running off 2x separate Amps, at EXACTLY the same time?
1x Amp (Rated 550w RMS) >>>powering>>> 2x EV ELX112 Cabs (Rated 250w RMS/1000w PEAK)
1x Amp (Rated 550w RMS) >>>powering>>> 2x Custom Built Volt Cabs(Rated 300w RMS/???w PEAK)
The Amps are only linked via the through ins/outs.
I was DJ-ing the other week. I don't believe I was driving the set-up any harder than I have many >times before. I had a very clear undistorted sound as normal. Then, after about 4hrs the sound just >failed!? I was left with just the high/tweeter frequencies and no mid/bass at all, in any of the cabs.
After further investigation it looks like 4 out of 6 drivers have been burnt! They are tight in their >chassis and have a Zero Ohm-age reading.
Any knowledge or advice would be most appreciated.
Many thanks,
Dan.

Overpowering is the only thing that "cooks" speakers. All your speakers are being driven with amps capable of exceeding the rms limits of your drivers without clipping them if you are playing music with very low crest factor like EDM/sign wave stuff. Or if you're clipping your DJ mixer. Any clipping of the amps will result in up to 2x the rated clean power of the amps into the load. That would be 1100W in this case. 4 hours in any of these scenarios is a lot of heat for those voice coils to handle and they may have already had some damage from prior incidence.

Here's a link to an excellent article by AAPLS contributor Phil Allison on the subject: http://sound.westhost.com/articles/speaker-failure.html

p***@gmail.com

2014-09-05 13:13:57 UTC

Post by cameronproaudio
http://sound.westhost.com/articles/speaker-failure.html

** The para at the end of part 3.2 might be relevant to the OP's question.

Another factor is that as each woofer FAILS in a live sound or disco system, operators are prone to INCREASING the drive power to compensate the loss of dBs.

An invariably fatal move ...

.... Phil

Peter Larsen

2014-09-03 14:43:30 UTC

Post by n***@gmail.com
How would it be possible to damaged/burn out 4x bass/mid
driver >units, in 4x separate cabinets, running off 2x
separate Amps, at EXACTLY the same time?

Massive overpowering should do fine. If you are lucky - or whatever you will
call it - you can get real pyrotechnics of the costly kind.

You need to understand the role of the sales department in specifying
things. Divide any loudspeakers integrated nonsense rating by at least 3 to
get a probable rms power rating.

Post by n***@gmail.com
1x Amp (Rated 550w RMS) >>>powering>>> 2x EV ELX112 Cabs
(Rated 250w RMS/1000w PEAK)
1x Amp (Rated 550w RMS) >>>powering>>> 2x Custom Built Volt
Cabs(Rated 300w RMS/???w PEAK)

Substitute integrated nonsense for RMS in the above and it gets probable.
Notice how hot a 500 watt lamp gets.

Post by n***@gmail.com
Dan

Kind regards

Peter Larsen

Sean Conolly

2014-09-04 05:08:01 UTC

<***@gmail.com> wrote in message news:d4a955ff-5e03-430a-9ffd-***@googlegroups.com...
Hi Folks,

Hope all is well.

Please can I pick your brains for a moment?!

How would it be possible to damaged/burn out 4x bass/mid driver units, in 4x
separate cabinets, running off 2x separate Amps, at EXACTLY the same time?

My set is/was:
1x Amp (Rated 550w RMS) >>>powering>>> 2x EV ELX112 Cabs (Rated 250w
RMS/1000w PEAK)
1x Amp (Rated 550w RMS) >>>powering>>> 2x Custom Built Volt Cabs(Rated 300w
RMS/???w PEAK)

The Amps are only linked via the through ins/outs.

I was DJ-ing the other week. I don't believe I was driving the set-up any
harder than I have many times before. I had a very clear undistorted sound
as normal. Then, after about 4hrs the sound just failed!? I was left with
just the high/tweeter frequencies and no mid/bass at all, in any of the
cabs.

After further investigation it looks like 4 out of 6 drivers have been
burnt! They are tight in their chassis and have a Zero Ohm-age reading.

Any knowledge or advice would be most appreciated.

=========================================

Advice? Turn it down. More speakers and less watts. More efficient speakers
and less watts. Or just better speakers, like the EAW LA212.

The ELX are $300 each, don't expect them to handle a lot of abuse.

Sean

Daniel Catherall

2014-09-06 12:57:41 UTC

Post by n***@gmail.com
Hi Folks,
Hope all is well.
Please can I pick your brains for a moment?!
How would it be possible to damaged/burn out 4x bass/mid driver units, in 4x separate cabinets, running off 2x separate Amps, at EXACTLY the same time?
1x Amp (Rated 550w RMS) >>>powering>>> 2x EV ELX112 Cabs (Rated 250w RMS/1000w PEAK)
1x Amp (Rated 550w RMS) >>>powering>>> 2x Custom Built Volt Cabs(Rated 300w RMS/???w PEAK)
The Amps are only linked via the through ins/outs.
I was DJ-ing the other week. I don't believe I was driving the set-up any harder than I have many times before. I had a very clear undistorted sound as normal. Then, after about 4hrs the sound just failed!? I was left with just the high/tweeter frequencies and no mid/bass at all, in any of the cabs.
After further investigation it looks like 4 out of 6 drivers have been burnt! They are tight in their chassis and have a Zero Ohm-age reading.
Any knowledge or advice would be most appreciated.
Many thanks,
Dan.

Thanks Folks!

I had read Phil's article (great read) before posting on here.

What I don't understand is why there wouldn't be any obvious signs of distress like distortion? The sound was very clear.

When I contacted EV HQ with the same details I got this reply...

"This does seem very odd indeed and having had an in-depth conversation with my team in the UK and in Germany, it would be highly unlikely for all the units to be defective at the same time."

"The reason for such a massive failure could lead to a number of possible answers, the first and most common reason would suggest a spike in local power to the units causing the units to fail."

"Another reason could be a square wave frequency to take out the components, although the protection fuse on the ELX112 would not or should not allow such a failure."

"In regards to the amps, we always recommend more headroom on the amps, its when there isn't enough headroom we have problems.."

...what do you folks think about this?

Have you ever experienced driver damage through Power Spikes/Surges? I'm aware that there are Power Conditioners available to protect equipment.

But would it be possible for a Power Spike/Surge to damage 4x Drivers but leave all the other gear (Mixer, Laptops, CDJ's, Amps, Lights) undamaged?

Many thanks,
Dan.

Phil Allison

2014-09-07 03:59:22 UTC

Post by Daniel Catherall
I had read Phil's article (great read) before posting on here.

** Thanks.

Post by Daniel Catherall
What I don't understand is why there wouldn't be any obvious signs of distress like distortion? The sound was very clear.
When I contacted EV HQ with the same details I got this reply...
"This does seem very odd indeed and having had an in-depth conversation with my team in the UK and in Germany, it would be highly unlikely for all the units to be defective at the same time."
"The reason for such a massive failure could lead to a number of possible answers, the first and most common reason would suggest a spike in local power to the units causing the units to fail."
"Another reason could be a square wave frequency to take out the components, although the protection fuse on the ELX112 would not or should not allow such a failure."
"In regards to the amps, we always recommend more headroom on the amps, its when there isn't enough headroom we have problems.."
...what do you folks think about this?

** Standard line of BS from a speaker maker:

"Power surges, squares waves, amp too small ... blah blah blah... "

Post by Daniel Catherall
Have you ever experienced driver damage through Power Spikes/Surges? I'm aware that there are Power Conditioners available to protect equipment.
But would it be possible for a Power Spike/Surge to damage 4x Drivers but leave all the other gear (Mixer, Laptops, CDJ's, Amps, Lights) undamaged?

** In a word - no.

If you really want to find the cause of failure of the four speakers, you will have to remove the cones and voice coils from the frames for inspection.

The easiest way is to cut around the outer edges of the cone and the spider with a "box cutter" or retractable blade knife. Snip the feed wires and the cone should come free.

Refer to my article for help with post mortem....

... Phil

Daniel Catherall

2014-09-07 16:31:19 UTC

Post by n***@gmail.com
Hi Folks,
Hope all is well.
Please can I pick your brains for a moment?!
How would it be possible to damaged/burn out 4x bass/mid driver units, in 4x separate cabinets, running off 2x separate Amps, at EXACTLY the same time?
1x Amp (Rated 550w RMS) >>>powering>>> 2x EV ELX112 Cabs (Rated 250w RMS/1000w PEAK)
1x Amp (Rated 550w RMS) >>>powering>>> 2x Custom Built Volt Cabs(Rated 300w RMS/???w PEAK)
The Amps are only linked via the through ins/outs.
I was DJ-ing the other week. I don't believe I was driving the set-up any harder than I have many times before. I had a very clear undistorted sound as normal. Then, after about 4hrs the sound just failed!? I was left with just the high/tweeter frequencies and no mid/bass at all, in any of the cabs.
After further investigation it looks like 4 out of 6 drivers have been burnt! They are tight in their chassis and have a Zero Ohm-age reading.
Any knowledge or advice would be most appreciated.
Many thanks,
Dan.

Cheers Phil, I will have a good look at them.

What would your thoughts be on the lack of distortion or signs of distress though?

Also, I'm pretty concerned about the idea of faulty amps/gear being the culprit. I have read quite a few articles that mention 'DC Current' damage to speakers. What are your thoughts on this? If it is possible, would a 'DC Current' fault be likely to effect 2x pairs of cabs powered by 2x separate amps (linked via through ins/outs)?

Is there an easy way to check for faulty 'DC Current' output from amps/other gear?

Thanks,
Dan.

Phil Allison

2014-09-08 07:44:14 UTC

Post by Daniel Catherall
Is there an easy way to check for faulty 'DC Current' output from amps/other gear?

** A voltmeter - ie any multimeter will do to check for DC voltage.

However, it is *very rare* for a power amp to have a serious DC fault and STILL WORK !!! Same goes for other items and in any case DC will not be transferred to the output of a power amp ( Crown's old DC300A not withstanding... )

Until you can verify IF the for speakers have BURNT voice coils or not, there is no point in any more theorising.

BTW

Burt voice coils typically have a terrible smell if you put your nose up close.

.... Phil

Daniel Catherall

2014-09-09 00:10:41 UTC

Post by Phil Allison

Post by Daniel Catherall
Is there an easy way to check for faulty 'DC Current' output from amps/other gear?

** A voltmeter - ie any multimeter will do to check for DC voltage.
However, it is *very rare* for a power amp to have a serious DC fault and STILL WORK !!! Same goes for other items and in any case DC will not be transferred to the output of a power amp ( Crown's old DC300A not withstanding... )
Until you can verify IF the for speakers have BURNT voice coils or not, there is no point in any more theorising.
BTW
Burt voice coils typically have a terrible smell if you put your nose up close.
.... Phil

Thanks Phil.

I'm guessing it's very unlikely then. If there was a DC fault, could it be passed from one Amp to the other via Through Ins/Outs? Are most Amps protected against this?

Where would I check for obvious DC Leakage/faults?

Will check the Voice Coils asap.

Cheers,
Dan.

Lord Valve

2014-09-09 02:25:42 UTC

Post by Phil Allison
Burt voice coils typically have a terrible smell if you put your nose up close.

Who's Burt? And most folks have a terrible smell if you put your nose up close...

Hi, Phil...sorry, couldn't resist. ;-)

Lord Valve
ASD fucked autistic criminal septic (etc.)

geoff

2014-09-11 00:51:04 UTC

Post by Phil Allison

Post by Daniel Catherall
Is there an easy way to check for faulty 'DC Current' output from amps/other gear?

** A voltmeter - ie any multimeter will do to check for DC voltage.
However, it is *very rare* for a power amp to have a serious DC fault and STILL WORK !!! Same goes for other items and in any case DC will not be transferred to the output of a power amp ( Crown's old DC300A not withstanding... )
Until you can verify IF the for speakers have BURNT voice coils or not, there is no point in any more theorising.
BTW
Burt voice coils typically have a terrible smell if you put your nose up close.
.... Phil

I had a pair of Wharfedale (real ones) that gave a nice little whisp of
smoke (a la cartoon smoking) when an amp went ape and put out 90VDC ....

geoff

Steve M

2014-09-08 12:15:44 UTC

Post by n***@gmail.com
How would it be possible to damaged/burn out 4x bass/mid driver units, in
4x separate cabinets,
running off 2x separate Amps, at EXACTLY the same time?

Obviously burnt voice coils. Given that it was separate boxes off separate
amps the cause must lie upstream from the amps.
Were you trying to get more bass out of these boxes than they are capable
of? Did the system have any kind of crossover
ahead of the amps or a high pass filter of some type?
Long term abuse of a driver leads to failure. If the system had no HPF to
keep subsonic frequencies out of the drivers you
could have been running the system below it's capabilities re: LF signal. It
is entirely possible that your rig was trying to
reproduce sub frequencies it cannot really handle and though you can't
actually hear those they will cook voice coils easily.
You did not say which amps you are using (make/model). So your info is
incomplete and too vague for a valid analysis.
For instance, do the amps have HPFs?

--
Steve McQ

Daniel Catherall

2014-09-09 00:03:42 UTC

Post by n***@gmail.com
How would it be possible to damaged/burn out 4x bass/mid driver units, in
4x separate cabinets,
running off 2x separate Amps, at EXACTLY the same time?

Cheers Steve,

I thought this was strange too, 4x separate cabinets with 2x separate amps. 2x cabinets with 300W RMS rating (2x 8" 150W RMS drivers in each) and 2x cabinets with 250W RMS rating.

I might have be a little guilty of trying to get more bass out of them, +3dbs on the Mixer maybe?!?

No Crossover or HPF.

They failed on LMFAO 'Sexy and I Know It" !!! I have played that track (and other dance stuff) many times before with zero problems.

I use 2x Thomann TSA 2200 Amps, 1x for the Volt Cabs and 1x for the EV ELX112 cabs. I don't believe I ever clipped the amps?!

Cheers,
Dan.

cameronproaudio

2014-09-09 00:21:50 UTC

Post by n***@gmail.com
How would it be possible to damaged/burn out 4x bass/mid driver units, in
4x separate cabinets,
running off 2x separate Amps, at EXACTLY the same time?

Cheers Steve,
I thought this was strange too, 4x separate cabinets with 2x separate amps. 2x cabinets with 300W RMS rating (2x 8" 150W RMS drivers in each) and 2x cabinets with 250W RMS rating.
I might have be a little guilty of trying to get more bass out of them, +3dbs on the Mixer maybe?!?
No Crossover or HPF.
They failed on LMFAO 'Sexy and I Know It" !!! I have played that track (and other dance stuff) many times before with zero problems.
I use 2x Thomann TSA 2200 Amps, 1x for the Volt Cabs and 1x for the EV ELX112 cabs. I don't believe I ever clipped the amps?!
Cheers,
Dan.

If you weren't clipping the amps, I'm betting that the issue is due to pushing too much low end into them. Like Phil said, until you cut them open to examine the voice coils, you're not going to know for sure. In any case, after you get the drivers re-coned, you might want to invest in some subwoofers and take the low frequency work away from the tops with a proper crossover. Your rig will sound better and your tops will not have to work as hard, especially the 12s. That will also reduce distortion and increase clarity.

Daniel Catherall

2014-09-09 16:26:39 UTC

Post by n***@gmail.com
How would it be possible to damaged/burn out 4x bass/mid driver units, in
4x separate cabinets,
running off 2x separate Amps, at EXACTLY the same time?

Cheers Steve,
I thought this was strange too, 4x separate cabinets with 2x separate amps. 2x cabinets with 300W RMS rating (2x 8" 150W RMS drivers in each) and 2x cabinets with 250W RMS rating.
I might have be a little guilty of trying to get more bass out of them, +3dbs on the Mixer maybe?!?
No Crossover or HPF.
They failed on LMFAO 'Sexy and I Know It" !!! I have played that track (and other dance stuff) many times before with zero problems.
I use 2x Thomann TSA 2200 Amps, 1x for the Volt Cabs and 1x for the EV ELX112 cabs. I don't believe I ever clipped the amps?!
Cheers,
Dan.

Cheers Steve,

Yes, I'm looking at Subwoofers and Crossovers/Speaker Management as we speak. Do you use Limiters?

I was maybe a little naive to think I could get away with using 2x Cabs (with 2x 150w Mid/Bass Volt Drivers in each) as Subs.

Do you use Power Conditioners or anything to protect against potential Power Spikes/Surges?

Phil Allison

2014-09-10 02:48:30 UTC

Post by Daniel Catherall
Do you use Power Conditioners or anything to protect against potential Power Spikes/Surges?

** Like a dog with a bone - ain't it.

.... Phil

cameronproaudio

2014-09-10 16:14:09 UTC

Post by n***@gmail.com
How would it be possible to damaged/burn out 4x bass/mid driver units, in
4x separate cabinets,
running off 2x separate Amps, at EXACTLY the same time?

Post by Steve M
Obviously burnt voice coils. Given that it was separate boxes off separate

amps the cause must lie upstream from the amps.
Were you trying to get more bass out of these boxes than they are capable
of? Did the system have any kind of crossover

Post by n***@gmail.com

Post by Steve M
ahead of the amps or a high pass filter of some type?

Long term abuse of a driver leads to failure. If the system had no HPF to
keep subsonic frequencies out of the drivers you
could have been running the system below it's capabilities re: LF signal. It
is entirely possible that your rig was trying to
reproduce sub frequencies it cannot really handle and though you can't
actually hear those they will cook voice coils easily.
You did not say which amps you are using (make/model). So your info is
incomplete and too vague for a valid analysis.
For instance, do the amps have HPFs?
Steve McQ

Cheers Steve,
I thought this was strange too, 4x separate cabinets with 2x separate amps. 2x cabinets with 300W RMS rating (2x 8" 150W RMS drivers in each) and 2x cabinets with 250W RMS rating.
I might have be a little guilty of trying to get more bass out of them, +3dbs on the Mixer maybe?!?
No Crossover or HPF.
They failed on LMFAO 'Sexy and I Know It" !!! I have played that track (and other dance stuff) many times before with zero problems.
I use 2x Thomann TSA 2200 Amps, 1x for the Volt Cabs and 1x for the EV ELX112 cabs. I don't believe I ever clipped the amps?!
Cheers,
Dan.

Cheers Steve,
Yes, I'm looking at Subwoofers and Crossovers/Speaker Management as we speak. Do you use Limiters?
I was maybe a little naive to think I could get away with using 2x Cabs (with 2x 150w Mid/Bass Volt Drivers in each) as Subs.
Do you use Power Conditioners or anything to protect against potential Power Spikes/Surges?

My particular setup uses an XTA speaker processor with 2-stage limiting that does both rms and "look-ahead" peak limiting which is very effective for protection. It's also very expensive and overkill for your setup. Power "conditioners" are useless for amps. And they're of questionable utility for everything else. Voltage regulators might be helpful for sensitive gear in environments with truly unstable voltage. If you're concerned about damaging voltage spikes, series mode surge protectors are the best way to go. Most of the common "surge protectors" out there have components that don't last and can dump leakage current into ground causing noise problems in some gear. Additionally, they shunt surge voltages to neutral and ground which can have other negative consequences for other gear on the same branch circuit.

Daniel Catherall

2014-09-10 17:02:53 UTC

Post by n***@gmail.com
How would it be possible to damaged/burn out 4x bass/mid driver units, in
4x separate cabinets,
running off 2x separate Amps, at EXACTLY the same time?

Post by Steve M
Obviously burnt voice coils. Given that it was separate boxes off separate

amps the cause must lie upstream from the amps.
Were you trying to get more bass out of these boxes than they are capable
of? Did the system have any kind of crossover

Post by n***@gmail.com

Post by Steve M
ahead of the amps or a high pass filter of some type?

Cheers Steve,
I thought this was strange too, 4x separate cabinets with 2x separate amps. 2x cabinets with 300W RMS rating (2x 8" 150W RMS drivers in each) and 2x cabinets with 250W RMS rating.
I might have be a little guilty of trying to get more bass out of them, +3dbs on the Mixer maybe?!?
No Crossover or HPF.
They failed on LMFAO 'Sexy and I Know It" !!! I have played that track (and other dance stuff) many times before with zero problems.
I use 2x Thomann TSA 2200 Amps, 1x for the Volt Cabs and 1x for the EV ELX112 cabs. I don't believe I ever clipped the amps?!
Cheers,
Dan.

Cheers Steve,
Yes, I'm looking at Subwoofers and Crossovers/Speaker Management as we speak. Do you use Limiters?
I was maybe a little naive to think I could get away with using 2x Cabs (with 2x 150w Mid/Bass Volt Drivers in each) as Subs.
Do you use Power Conditioners or anything to protect against potential Power Spikes/Surges?

Many thanks for the helpful advice Steve. Most appreciated.

It seems like the general consensus for 'Power Conditioners' is that they're a waste of time on the whole. I was looking at the Furman M-10X E or the Furman M-10LX E to do the job.

Woh! Those XTA's are pricey! Have you heard any positive/negative things about the Behringer DCX2496 Ultradrive Pro or the DBX DriveRack PA+ or are they just a waste of time too as far as protection?

Cheers, Dan.

cameronproaudio

2014-09-10 18:12:23 UTC