help... questions that bugged me for a long long time

[AScreenName 10+ year member]

forgot to mention that

 

[awalbert88 10+ year member]

Underpowering the sub will never hurt it. Overpowering the sub might hurt it, depending on the quality of the sub and the degree to which you overpower it.

That being said, the amp's build quality is far more important than the sub rating. For example, if you have a JBL 300.1 (300x1 @ 2ohm) and a JL 13W7 (1000W dual 1.5ohm), and you crank the gain on the 300.1 all the way up and push your HU volume to max, the amp is going to begin clipping, which will send very loud, very high tones through to the sub, which WILL damage it. If you push an amp too hard, and it starts to clip, then the quality of the sub becomes irrelevant, because it won't take long to destroy it that way. However, if you have a powerful amp (say, the Zapco 4kW model) and a relatively weak sub (JL 6W0 - 75w), and you turn the gain on the Zapco all the way down to where it is barely pushing any power, then the sub should be fine, and in fact would sound better than if a 75w amp were driving it, because the 75w amp would be running at full power, thus more likely to distort or overheat. So, more power is almost always better so long as you use it correctly.

Please feel free to correct me if I'm wrong on any of this, but I believe I have it correct.

 

[Wonderbread 5,000+ posts]

read that link I posted... in tehre it states taht if your sub is able to handle SIGNIFICANTLY (like your W7 and JBL analogy) it will be almost impossible to destroy it with a clipped signal...

 

[Savant 10+ year member]

Originally posted by awalbert88 Underpowering the sub will never hurt it. Overpowering the sub might hurt it, depending on the quality of the sub and the degree to which you overpower it.

 

That being said, the amp's build quality is far more important than the sub rating. For example, if you have a JBL 300.1 (300x1 @ 2ohm) and a JL 13W7 (1000W dual 1.5ohm), and you crank the gain on the 300.1 all the way up and push your HU volume to max, the amp is going to begin clipping, which will send very loud, very high tones through to the sub, which WILL damage it. If you push an amp too hard, and it starts to clip, then the quality of the sub becomes irrelevant, because it won't take long to destroy it that way. However, if you have a powerful amp (say, the Zapco 4kW model) and a relatively weak sub (JL 6W0 - 75w), and you turn the gain on the Zapco all the way down to where it is barely pushing any power, then the sub should be fine, and in fact would sound better than if a 75w amp were driving it, because the 75w amp would be running at full power, thus more likely to distort or overheat. So, more power is almost always better so long as you use it correctly.

 

Please feel free to correct me if I'm wrong on any of this, but I believe I have it correct.

Mostly right.. but what causes a speaker to blow from clipping is that you spend a significant amount of time 'stuck' at one position (top or bottom).. that generates a lot of heat (holding like that).. You also loose cooling motion (not moving at top/bottom means no moving air).. the lack of cooling and increased heat blows the coils.. Now, if you have a coil that can handle, say 200 degrees (your 1000W woofer) and the amp with clipping (you will still have 'some' cooling, just not optimal) causes the coils to heat to 150 degrees.. no problem (that's the "significantly more power handling of the sub").. That makes sense?

Oh, and you can over-power/blow a sub with a perfectly clean signal as well.. take that 4kW amp and set the gains to match the input level (normal setting).. the lowest volume will probably be ok, but as you turn up the volume and the amp puts out more and more voltage the sub will heat up.. too much juice.. and melt/blow the coils.. The signal from the amp is perfectly clean and, say, 1000 watts.. but the sub can only handle 250 rms.. that sub will blow (not talking about 'rated' rms or whathave you and under-rating.. I'm saying that the 250 is the real rms power.. over time it will go even though we aren't talking about peak)