Subwoofer to Amp Wattage

[only126db]

Reps are not always the smartest people in the world.
-Cody

You got me on that one, most I talk to dont know jack isht.

I tossed this out there just as a jab....

I honestly couldn't say whether this is fact or fiction on the underpowering, there is so much back and forth on the subject.

I wish I had the test equipment to be able to do the testing myself and prove the outcome one way or the other.

I generally tend to get an amp rated higher than my subs just due to the fact that music does not generally contain a flat non fluctuating signal as the signals used to determine/verify rms on subwoofers. (pink noise)

A signal producing 50% power and 200% peak power evenly equals 100% average which could be recognized as rms.

A 100watt rms sub getting 50 watts with 200 watt peaks evenly = 100rms, now if your amp is rated @ 100 watts and just barely makes that mark, with a supply voltage drop(if) you wont even hit that mark, but have a good chance of having crappy sound.

However if you have an amp rated to do 150 rms with the voltage drop and everything else you will have the ability to provide your sub with the needed power and have some extra for those musical peaks.

(The wattages above are just for illustration for ease)

[MacLeod]

I think we're all heading to the same place but taking different roads and maybe the problem we're running into here is defining "underpowering" and "overpowering".

It takes double the amount of power to increase output by 3 db which is generally the least amount that is audible so if you take a 100 watt speaker as an example, a 90 watt amp aint underpowering nor is a 120 watt amp overpowering.

So when I say "overpowering" Im talking about using at least 200 watts on that 100 watt speaker and when I say "underpowering" Im talking about less than 50 watts.

Now, you take that 200 watt amp and although it only amounts to a measly 3 db in audible output, its DOUBLE the amount of thermal energy that the voice coil now has to dissipate. So if youre not careful with the volume control, that 200 watts will build up enough heat in the voice coil to melt it.

Now take the 50 watt amp and put it on the 100 speaker. Now 50 watts aint much and you can run out of clean power really quick. So you crank on the volume a little more to get some extra grunt and WHAMMO! Youre amp is now clipping and shooting out around 120 watts. Now 120 watts is more than our speaker is rated to handle BUT its not a whole lot more and the voice coil will have a better chance of cooling. So while you are more likely to clip the 50 watt amp, it generally will be easier on the speaker than if you were steady pumping in 200 clean watts during a spirited listening session.

This is why I generally recommend using an amp that is rated the same as the speakers. Youre not really going to get any more output from a 100 watt amp over a 75 watt amp so the chances of clipping will be the same. Also youre not going to really get any more output going with a 125 watt amp so youre not more or less likely of clipping it.

[Jstas]

Clipping is not that simple. There is much more to it than just a power surge.