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?