Also dependent on what speakers you go for and if you get sub. You may be able to set the fronts, rears and centre to small or large. If go with all small, then LFE (low frequency effects) be re-directed to the sub. If set speakers to large, you may not need a sub. Depends on what speakers you have and if there is enough bass being outputed. I have a tannoy sfx sub and hardly use it, only cos I use digital stereo through external soundcard using optical cable, which gives me a 96khz output (dvd audio level), when cd audio is 44,100khz. sorry for slight waffle