Rms

If you have 2 400 RMS subs, do they need 800 RMS watts from the amp, or only a 400 RMS watt amp?

800 watts. You need to know the ohm rating too.

well you dont "need" 800w...that is just the maximum continuous power they can handle... what subs are you talking about...if they are a mainstream woofer such as MTX or Kicker they rate RMS over a short period of time (ie 10seconds maybe) where as higher quality woofers such as RE or DD or Barahma rate over long periods of time (ie 100 seconds) this means that MTX or kicker probably wont be able to handle but their RMS rating as actualy RMS... it should be called music power handleing...where as DD and Re can handle greater power because their RMS is true RMS... it is only recently that DD has been putting an actualy RMS, music, and peak power handleing...they used to only rate in RMS....but that was back in the day when they thought they would be big stereo buffs and prove that a 1000w RMS woofer could handle 3000w peak or more and since most amps couldnt supply 1000w RMS AND 3000 peak they would rarely damage woofers...now that DD has become more practical they put a music power handleing which is better because most amps can supply RMS at music power handleing and peak...by the way what woofers are you looking at anyway?

I always "overpower" my speakers when possible ...... but then I listen to music, as opposed to electronic bass tones

^^bass guitar in heavy metal or even country (huh?) will kill an over powered woofer also... :-P

^^bass guitar in heavy metal or even country (huh?) will kill an over powered woofer also... :-P

only if you turn it up past the speaker's limits....the same applies to an "underpowered" speaker too

the myth that under powering a woofer will blow it (clean power that is) was so retarded from the begining...i dont know how anyone beleived it... but ofcorse if you overpower a woofer it will eventually blow...doesnt mean if you put a 1600w amp on a 1000w woofer it will blow...only if yo uare actualy feeding it 1600w... :-P

yeah it is a pretty retarded myth

my point was that the power rating of the amp really makes no difference, if you push the speaker beyond its limits, either mechanically or thermally, it will blow. This can be done with an amp that's rated higher than the sub, and it can be done with an amp that's rated lower than the sub, it doesn't matter.

that "myth" started because lots of people were blowing speakers with amps that were rated at like half the power of the speakers. They didn't know that an amp could put out a lot more power when driven into heavy clipping.