Overpowering Speakers

Given a choice, I will take the bigger amp any day. You run less risk of damaging the speaker! A smaller amp, if overdriven, is how most tweeters in the world get damaged. In fact, if the tweeter is damaged in a speaker, the repair technician should always tell the user that the amplifier is under-powered.

Although the conclusions and suggestions that have been expressed in this thread are generally correct, the explanations of why tweeters are commonly damaged by underpowered amps are not.

Tweeters are not damaged by DC (it would be blocked from reaching them by the crossover network, if it were somehow generated in the first place), and amplifiers that are called upon to supply more power than they are capable of supplying do not output "raw electricity."

What typically happens is that the amplifier will not have the ability to generate the output voltages that correspond to the peaks of high volume low frequency or mid-frequency signals. That will result in the output waveform abruptly transitioning from a gradually rising or falling sinusoidal waveshape to a flat level, until later in each cycle when the signal returns to an amplitude the amp can handle.

That abrupt transition contains high frequency spectral components (frequency components) which are not present in the original music waveform. Since they are at high frequencies, the crossover network in the speaker routes them to the tweeter, which is therefore called upon to handle a greater amount of high frequency energy than a normal music signal would require. That is what does the damage.

Best regards,
-- Al

Thanks Al,
I was trying to make very general terms understandable and as much as you are generally correct. Crossovers do see DC as High frequency and do route 1st to the tweeter. This DC is raw current. Crossovers do not block DC. In fact, Through the years, I have used circuit breakers to protect against current and have even put small light bulbs on 6x9's in cars. The kids used to think it was very cool to see them flash with the music. The sole purpose of these bulbs was to filter off DC. It worked very well.

This is from Club knowledge, an article about clipping distortion. I hope this makes sense. Tim

Glad you asked! The amp will try to meet the power demand placed upon it, but it cannot exceed its design capabilities. This in turn, produces the deadly "square wave" output to the speaker. The speaker sees this severely clipped signal as DC current. Speakers cannot deal well with DC inputs. The cone goes in or out and stays there. No motivation to cool the voilce coil and sooner or later, the speaker will fail.

YEAH... YEAH... SO WHAT CAN I DO TO PREVENT THIS?

Alright, we know what clipping is, how it affects amps and speakers. What do we do to keep this problem from destroying our expensive drivers? Easy deal:

1. Use amps that closely match or modestly exceed the power rating of the speaker. A 100 watt speaker will love getting 125 watts of "clean power" vs a 100 watt speaker getting 25 watts of badly clipped (distorted) power.

2. Know what distortion sounds like and prevent it by proper amp setup procedures. (HU/amp gain matching, limited bass boost usage)

3. If you are not sure your system is clipping, best thing to do is get out
of the vehicle, open the doors and step to the rear of the vehicle about 10 feet and listen...

a. Are the highs and mids clear and natural sounding or harsh, shrill and very poor SQ? You are clipping the amp if you hear the latter!

b. Does the bass sound full, tight, have a definite thump and smooth transitions from one note to another? If not, good chance the sub amp is clipping or your enclosure design is not optimal for the subs.

OK, that's about all I can do for now on this topic... Class dismissed and PLEASE... NO CLIPPING ALLOWED !!! 15 yard penalty and you will pay the piper eventually.

Sorry everyone if I have put you through all of this, I hope it has been beneficial, but I think that I'm going to leave this one alone, I didn't sign on to argue or prove anything, only to help, I'm a big stickler on seperating fact from opinion. I need to learn when to quit, I'm not trying to hurt feelings.
See you on the next thread,
Tim