Too Little Power

That was my fault. I know for a fact that is really confusing what I said. After reading what I wrote it did sound like I was then arguing the fact on whether a speaker can be blown on too much power. There is no way I would argue this fact as I know that a loudspeaker can definitely blow on too much power.

As for the too little power, I believe I stated that perfectly in my last post. I should have left the end part out because that statement just caused confusion and shouldn't have been in there.

Underpowered = running your amp wide open = A clipped sine wave (signal) = DC power to the speaker = No control, excessive heat build up = failure. END OF DISCUSSION.

From some of these posts, I am gathering that when an amp clips, it sends DC voltage to a voice coil.  When the DC voltage gets to the coil, it must stop moving all together and burn up the coil.  I was under the impression that when an amp clips it has 2 points that the clipping is visible, one on the positive side of the waveform, and one on the negative side of the waveform.  So with a 25 WPC amplifier clipped as hard as it can be played, which of the DC voltages is damaging the speaker?   Is it the +10 volts, or is it the -10 volts?  If the amp is clipping, and the input signal is an AC voltage, how does it go from +10 to -10 without moving the cone of the woofer?  Oh wait it can't do that.  The cone of the woofer is still moving, so it is still cooling.  Clipping a small amp as severely as possible will not damage a woofer.  Unless the power handling rating of the woofer is exceeded.  The DC theory will only destroy a speaker if it is either a positive or a negative DC.  If you clip an amp, the speaker is still moving.  A moving speaker is a happy speaker.

As a former installer who recieved factory training from both Kicker and JL Audio Techs,I was taught"too much power blows mids and highs,distortion blows subs".If you give a 250 watt (rms) rated sub,500 rms watts of undistorted signal it will play perfectly fine.But if you give the same sub 200 rms watts of a distorted (clipped) signal you are very likely to fry the voice coil.Basically from heat and the non linear movement of the speakers cone,wich causes the voice coil to move out of the magnetic gap it floats in and possibly causing it to touch the walls of the motor structure because of the non linear movement.Also the coating on the windings of the voice coil will get hot enough to bubble.This causes the sceatching sound you sometimes hear if you push the cone of a blown sub.In extreme cases it will bubble enough to make it swell enough to lock the voice coil in the gap.You may have seen this in a blown sub where you push on the spesker cone and it doesn't move in or out.Our Kicker Tech had a 12" Comp VL that was sent in and thet cut the speaker in half right through the motor structure basket cone spyder etc. so we could see the damage he was talking about.I personally have had subs come back to the shop blown,and the customer is saying how could I blow a 500 watt speaker with a 300 watt amp? The first thing I would check is where the gain was on their amp.Usuall it would be all the way up.I would try and explain to them that the gain is not a "rear volume controler" I also noticed it was easier to blow subs in a bandpass box than in sealed enclosures.Someone else mentioned in a comment about blowing subs from hard bottoming.I was taught that if your sub was bottoming out (voice coil hitting the bottom of the motor structure),then your box has a leak in it.A well sealed enclosure can't bottom out because the air inside the box becomes part of the suspension system helping to control cone motion.Limiting cone movement and preventing the voice coil from such extreme linear movement.Also most subs have bumped out back plates on the pole and magnet to help prevent it even more.