A high power rating for say, a 4x10 cab, is around 700W RMS. I use a 800W amp. to power 2 700W enclosures (1400W total). The power amp. section will definately clip when cranked up, resulting in a loud CRACK on the attack of hard-plucked (mostly low) notes. Does this not mean that I am giving the speakers as much as they can handle? So, even if I had a 2400W amp., with the same speakers, I couldn't get any louder because I'd be clipping the amp at the same point (assuming similar tone settings), right? It seems I need more speaker. Most cabs. are 4 or 8 ohms, and the min. ohmage you'll likely want to put on your amp is a 4 ohm load. This means that to maximize sound you'll typically use a max. of two (8 ohm) cabs. with a single amp. So, even if I had more speaker, I couldn't use it because the ohmage would drop too low for a single amp. Why then are people using separate pre/power units with big PA amps with a ton of power?