Axiom Home Page Forums General Discussion Home Theater M80's and Bi-Amping???

If the same signal is fed into the two 200W amps then you're generally going to get the same effect as a single 200W amp. If you had a crossover before the amps so that LF went into one amp and HF into the other you would get the effect of a more powerful amp, although the benefit you get would be a function of how power is split between HF and LF.

In "real" biamp systems the LF amp is normally quite a bit more powerful than the HF amp, so that both amps reach their limits at about the same volume. If the really low notes are being filtered out and sent to the subwoofer (and not to the two amps) it's possible that the power distribution between the remaining LF and the HF might be more balanced, not sure.

In terms of "how power works" the main thing to remember is that a 200W amp is rated to put 200W into a specific impedence, which really translates into "putting enough voltage to get 200W into that impedence" without going into current limiting in the process. The current drawn by the speaker is a function of both the voltage and the impedence (in DC terms it's voltage squared over resistance), so a bigger amp needs to be able to output more voltage *and* more current.

If you have a 4 ohm speaker it will draw more current at a given voltage than an 8 ohm speaker, which will give you more power at the same volume control setting -- assuming the amp is able to actually provide that much current. This is why you see amp ratings like "200W at 8 ohms, 400W at 4 ohms, not recommended for <4 ohms". It's also why you see questions about whether a specific amp is a good match for a 4 ohm speaker.

In the case of the EP800 you really are getting the full 800W since both voice coils are handling the same frequency range.