Overpowering Speakers

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

Don't worry about your 300wpc amp powering your 100wpc speakers. You do not have to match the numbers. As stated above, it is much more likely to overdrive a low powered amp to clipping and damage a tweeter. You will hear the strain when over driving your speakers with clean power, so back off when they sound like they might explode!
By the way, an amp has to malfunction to "send DC" to your speaker. That is not what "clipping" is.

Tim, I sincerely appreciate your gentlemanly responses and your good intentions. However, I too feel a responsibility to separate fact from mis-information.

As someone with multiple electrical engineering degrees, and multiple decades of experience in electronics design, I can tell you that DC is not "seen as high frequency"; that a clipped audio waveform is not DC and is not seen as DC (as Blkadr correctly indicated, and contrary to what is stated in the article you quoted); and that the portion of a crossover network that is between the speaker terminals and the tweeter (which is designed to pass high frequencies and to block low frequencies, and may be simply a capacitor in series, or something that is similar at a simplified conceptual level but more elaborate) will block DC. DC is actually the LOWEST possible frequency, zero Hertz. Capacitors block DC, and impede low frequencies.

If DC is ABRUPTLY applied to a circuit, high frequency components may be briefly present, corresponding to the abruptness of the change in voltage. Those are referred to as transients. Similarly, the abrupt waveform changes I referred to in my earlier post, that occur when a LOW frequency waveform is clipped, contain HIGH frequency spectral components.

Which leads me to simply reiterate that my earlier post correctly explains why tweeters are commonly damaged by the clipped waveforms that can be generated by underpowered amps.

Best regards,
-- Al

The OP question of (my interpretation) "can I use a 300 watt amp with speakers rated for only 100 watts safely" has not really been addressed.
Yes you can use the 300 watt amp with 100 watt rated speakers if you abide by some rules.
First, the amp is just like the wall outlet in terms of raw power. The wall can allow up to 15 amps.. but a small light bulb only needs 25 watts. The wall just lights up the lightbulb, using 25 watts. So the rating of the wall socket of 15 amperes does not matter, unless you stuck a couple of screwdrivers into the wall and crossed them. Then your 15 amps would give you a big spark and a tripped breaker.
The VOLUME control is more like the limiter in the case of stereo. So you can use the big power amp with smaller rated speakers IF YOU KEEP THE VOLUME DOWN to non-earsplitting levels.
When you are listening at very low sound volumes, the wattage is like one watt or less actually being used to power the speakers. So even though the amp is rated at up to 300 watts, it is actually using just a watt or so to drive the speakers. When you play music loud enough to allow a person in the next room to hear, you are probably around 50 watts or so, and when your neighbor down the block can hear your music clearly, your speakers will burn out, because then you WOULD be exceeding the speakers rated 100 watts average.
So take it easy on the volume control and do not play louder than you can generally put up with if you were a foot from the speakers, and you will never have a problem.
Watch out for drunken guests, and small children though, as they may turn UP the volume to fatal (for your speakers) level.
Say if you turn it on and accidentally had the volume all the way up and the blast hit your ears and you immediately turn it down... You will probably not damage the speakers (because the speaker coils did not have enough time to overheat and melt... this is with 300 watts.. if you had 1,000 watts.. I think your speakers would be toast with a 100 watt rating, even if it was only for a second.)
=========================================================
So the answer is yes you can safely use a 300 watt amp with 100 watt rated speakers IF you keep the volume control from overdriving the speakers: IE too loud to stand listening. And you are good.
This means NO body massaging bass attempts. no 'can I break my lease" levels.
Hope this helps.