Can loudspeakers really catch fire if you crank the volume?
luvp...@hotmail.com
on Music" and in the introduction he says that in his college days he
listened to music at such high volumes that: "I actually set my
loudspeakers on fire by cranking the volume too high." Is this
hyperbole, or can this really happen? Has anybody here ever
experienced this? Thanks!
dpierce.ca...@gmail.com
The short answer is no, it can't happen.
The long answer is still no.
I have, for a variety of clients, done extreme stress testing
of loudspeakers to the point of irrecoverable failure under
a wide variety of circumstances. I have driven voice coils
to the point of melting the attached domes, to beyond the
point of boiling the ferrofluid out of the gap, and so on.
In THOUSANDS of cases, there does not exist a single
case of ANY of them coming remotely close to catching
fire. In all cases, the electrical system simply opened
up first.
There was once a high-end store in Harvard Square
which had a pair of EPI 100 speakers where the center
of the cone was charred and burned through, and the
store's claim was that their McIntosh amplifiers were
so powerful that they set the speakers on fire. A friend
bought the speakers for $5 as a curiosity and brought
them buy. The burn pattern was VERY curious, indeed.
While the cone was indeed burned, as in fire, the voice
coil itself was perfectly intact and had NO signs of
ANY thermal stress whatsoever. Further, the speakers
had their grills, and there was no sign of soot or ash
in the backside of the grill cloth, even thoughthe cones
were extensively damaged.
The conclusion was simple: the single case that I was
able to examine where there was visual evidence of a
fire was deliberately burned with a torch as a sales
gimmick.
The reasons it can't happen are many. In most cases,
the voice coil or the solder joints for the flex leads or
the power supply caps give up LONG before there's
enough heat generated to raise the temperature to
the ignition point of the cone. The voice coil is buried
in a steel structure that conducts a LOT of the heat
away. The speakers at that point are sounding SO
awful by being so several overdriven that they are
beyond intolerable to listen to. And so on.
It's urban legend, short and sweet.
Now, you want STUPID loud? I once knew a kid
who would brag about the fact that he would take
his Phase Linear 700 and hook it to his Bose 901's
and set them up almost like giant headphones
and play it SO loud his ears would bleed. He
though it was WAY cool.
I met him about 5-8 years later and he was a sorry
young man in his mid 20's who was almost completely
deaf.
Peter Wieck
Oh, I dunno...
You are assuming well-made, well-designed speakers that would
generally fail as you describe from being over-driven.
However, here are a few designed-to-fail situations:
http://www.youtube.com/watch?v=TSqy7p--O2c
http://www.youtube.com/watch?v=oNBdWfBgqXk
Sub-woofers are strange beasts - and those designed for vehicles yet
stranger. One needs suspend assumptions when dealing with such
animals. Catching fire from being over-drive would not surprise me at
at all given that the are designed simply _not_ to fail from whatever
abuse as might be thrown at them.
I do remember one "legend" - an AR rep stating that their AR-9
speakers could be plugged into a wall and not sustain damage for at
least ten full minutes. Yeah... right... Imagine that warranty claim.
Peter Wieck
Melrose Park, PA
---MIKE---
>I do remember one "legend" - an AR rep
> stating that their AR-9 speakers could
> be plugged into a wall and not sustain
> damage for at least ten full minutes.
> Yeah... right... Imagine that warranty
> claim.
I remember that claim but I think it was for the AR-1W - not the AR-9.
---MIKE---
>>In the White Mountains of New Hampshire
>> (44° 15' N - Elevation 1580')
Serge Auckland
news:fvo34...@news1.newsguy.com...
When I was a student in the late 60s, I occasionally did discos for parties.
I once needed a long 'speaker extension, there wasn't time to do it properly
so decided to use a 25 metre mains extension, live was left, neutral was
right and earth was the common ground. I wired a mains socket to banana
plugs to go in the back of the amplifier. At one point, for reasons that may
have had something to do with the amount of social intoxicants consumed, I
ended up plugging the 'speaker extension into the mains. The right hand
'speaker just hummed quietly, but the left hand went BANG. It was probably
the loudest noise I've ever heard. The cone (a 12" "full range" speaker)
actually flew out of the cabinet and landed on the floor with small flames
coming from the coil and former. Consequently, I can say that 'speakers CAN
catch fire if you plug them into the 240 volt mains.
S.
Sonnova
(in article <fvqnc...@news3.newsguy.com>):
I remember that! Can you imagine the row?
Eeyore
Yes, I've done it sort of intentionally to get rid of an old POS speaker
and get some amusement into the bargain.
I've heard of it happening in PA rigs when amps 'went DC' too back in the
70s and 80s when such events were more common.. JBL recones cost a pretty
packet too !
Graham
Eeyore
> On May 4, 3:31 pm, luvpoc...@hotmail.com wrote:
> > Hi, I just started reading Daniel Levitin's book, "This is Your Brain
> > on Music" and in the introduction he says that in his college days he
> > listened to music at such high volumes that: "I actually set my
> > loudspeakers on fire by cranking the volume too high." Is this
> > hyperbole, or can this really happen? Has anybody here ever
> > experienced this?
>
> The short answer is no, it can't happen.
>
> The long answer is still no.
WRONG again ! See my earlier post I can't see it happening with modern
Kapton coil formers
though !
Graham
Eeyore
> I do remember one "legend" - an AR rep stating that their AR-9
> speakers could be plugged into a wall and not sustain damage for at
> least ten full minutes. Yeah... right... Imagine that warranty claim.
Well ... even on 120V mains that's still 1.8 kW into 8 ohms ! I do know of a
speaker with genuine 1200 watts continuous rating (Precision Devices 24 inch
unit) but even that would fail.
Graham
Arny Krueger
news:fvqnc...@news3.newsguy.com
> Peter Wieck wrote:
>
>> I do remember one "legend" - an AR rep
>> stating that their AR-9 speakers could
>> be plugged into a wall and not sustain
>> damage for at least ten full minutes.
>> Yeah... right... Imagine that warranty
>> claim.
>
> I remember that claim but I think it was for the AR-1W -
> not the AR-9.
AR-1 woofers were kinda fragile by modern standards. But they did tend to
outlast the other drivers in the system, when they were used in the AR-3.
There are high-powered amps that easily put out 120 volts RMS into low
impedance loads without clipping. The speaker systems designed for use with
them can probably pass the plug-'er-into-the-power-line test. We're talking
live sound or car sound here.
---MIKE---
>AR-1 woofers were kinda fragile by
> modern standards. But they did tend to
>outlast the other drivers in the system,
>when they were used in the AR-3.
I'm still using a pair of AR-3 woofers for sub woofers in my system.
They ar driven by an Apt-1.