Without an electronic crossover to separate the woofy parts of the signal from the tweety parts I don't think you get any real benefit at all (other than lots of cool points). Since both the woofy and tweety amplifier channels are getting the same signal as before they are going to clip at roughly the same volume setting as before.
Now, if you were running 4 ohm speakers and the amp hit current limits before voltage limits (which is not unusual AFAIK) then (a) you could run at slightly higher volume levels before clipping and (b) you could, to a certain extent, clip without guilt because the harmonics from clipping would only go into the woofer not the tweeter, so not only would you not hear them as much but they wouldn't be able to damage your tweeter since it would be the woofy side of the amp clipping.
Back when I used to play with professional sound systems (and I stress the word "play" ;)) I remember the nice thing about bi-amped systems was that you could drive them hard into clipping and they didn't sound so bad 'cause the midrange and tweeter were still getting clean signals. You could also get more effective power but that was thanks to the electronic crossover before the amps. Also, the amps tended to be different sizes, usually with a big honkin' bass amp and a much smaller mid/high amp.
pulling numbers out of his ear...
Eww !! Did you wipe those numbers before posting ?
