I think I blew my amp??!!

Incidentally, I'm very impressed at the use of the word 'thwooob'. Haven't heard that piece of onomatopoeia for.. well... never I suppose...

Onomatopoeia huh... I think they have some kind of ointment that can help with that. ;-)

-Fred W

PS - that word is so cool sounding I just had to look it up. Thanks for the lesson.

OK, I take it all back. Spud guns can be seriously dangerous stuff. Check out this web site, especially the video:

Yikes...

-Fred W

Absolutely. If an amp damages a speaker, it's virtually always because the speaker is under-rated compared to the amp. Not the other way round.

I guess what you mean here is that the output starts to approximate to a squarewave, which has it's RMS value equal to it's peak. If that's the case, then I'm not disagreeing.

That's not a particularly good test - no cone movement means no airflow over the coil. You'd be better off using a squarewave within the speaker's operating range. Still, again, I don't disagree with the general idea that speaker power ratings are often stupidly misleading.

But what is it about the blackening which makes you think it was always caused by clipping? Certainly it's possible for a surprisingly small amp to knacker a surprisingly "high power" speaker, but you seem to be suggesting that the same speaker would survive if driven to the same volume level by a bigger amp running cleanly. That's only very rarely the case.

Cheers,

Colin.

Obviously you have, and you imagine that it affects the validity of your argument.

Cheers,

Colin.

i still do not know where the amp is in my car lol ???????

I found a coleman camping lantern flint to be simpler and quite reliable. Starting fluid makes an incredible fuel, in the right ratio you can blast a potato right through a piece of 1/2" plywood.

I certainly wouldn't call it relatively safe though, a direct shot would kill someone for sure. One of the more amazing things I've done was rip the top inch clean off an onopened can of nasty flavored pop, leaving the bottom portion of the can sitting undisturbed and filled to the brim. Doubt I could do that again though even if I tried a zillion times.

A friend of mine made one that made exactly that sound, then I improved on his design with a larger combustion chamber, smaller diameter and longer barrel, well oiled with silicone spray and ether as fuel, sounds very much like a high powered hunting rifle.

The *watt specs* on in car audio are utterly bogus and unreliable. They're usually measured at something like 10% distortion too !

If you had a multimeter you could check if the new speakers are still ok - either there will be some continuity across the terminals ( in which case they're ok ) or it's open circuit and they're broken.

You can substitute a small wattage light bulb, battery and some wires to do this job too actually.

Oh - you can't 'kill' an amp by fitting higher wattage speakers than the amp - that's ok - the other way round isn't so smart.

You do need to ensure that the speakers and amp are compatible *impedances* though. In car audio is normally 4 ohms.

Graham

What do you mean by 'properly' ?

Do they now make a nasty grating sound ?

Graham

Actually the amp doesn't put out 'spikes' - it puts out 'square waves' when clipping heavily. This can result in twice the continuous sine wave 'rms' power, never mind the lower 'average' power when playing music.

Graham ( audio design consultant )

Not compared to the square wave output capability of the amp ! That's if your ears can tolerate the abuse of course. ;-)

It doesn't.

Graham ( designer of pro-audio for > 30 yrs )

Never done done C but familiar with A, AB, B, D, G and H. IR has some lovely

100V mosfets just out with 10mohm on resistance - perfect for heatsinkless high power class D. In a surface mount package about 8x7mm too !

Graham

Actually that's not a fair test.

Any modestly rated power speaker relies on the voice coil movement to help cool it. In some cases *very much so*. The magnetic assembly also helps provide cooling. You'll see fins on the back of some high power speakers - they're not just there to look good. ;-)

I've even seen some high power rock concert systems that pump forced air cooling via 'plumbing' to cool the voice coils !

Graham ( audio genius )

Indeed, the DC resistance of a speaker voice coil is typically around 60% of its' nominal impedance. More amps flow @ DC = more watts = burn up - not to mention the absence of cooling by movement.

Graham

You'll be amused to know that 'does clipping cause tweeter burn out?' is a commonly recurring and much discussed topic in the pro-audio groups.

Considering they *ought* to know - there's still much debate. In the end it boils down to the long term power rating of the tweeter versus the crossover frequency.

Graham

Not quite. I *did* once connect an old 12" 25 watt speaker of no useful value to a 100 watt amp to conduct a similar test also when bored.

The result was quite smoky but absent of flames.

In the early days of high power sound reinforcement in the UK a certain brand of amplifiers was popular since they were about the only model made in the UK and available at a sensible price unlike US models.

Their internal cooling was 'optimistic' to say the least and it was popular for these to 'go DC'.

Such failures were indeed known to cause some spectacular speaker fires.

Graham

Hmmmm - I wish I had that link. A home-made flame thrower ! I kid you not.

Graham

Sounds good to me. The closest I ever got was when I tested my fuel injectors.

Cheers,

Colin.