BIAMPING


Its me again - SFrounds, Need help on biamping questions.

Stupid question#1
Why is it that an amp rated at 125 wpc can deliver 400 watts mono, why wouldn't it be 250?

Now for the rest of these questions, lets say I have two of these identical amps, and a pair of speakers that can be biwired.

Hopefully - not as stupid question#2
What is the best way to wire these amps?

(A)Have one amp wired to supply the low frequencies on each of the right and left channel speakers, and one amp wired to supply the high frequencies on each of the left and right channel speakers.(at 125 wpc each)

(B)Have the amps wired mono at 400 wpc with one amp biwired to the right channel speaker and the other amp biwired to the left channel speaker.

(C) none of the above or other recommended option.

Thanks again, (Don't worry I can Take abuse very well)
sfrounds
regarding (b), the rating of the speakers really wood depend on the capacity of the amp to deliver current. my electrocompaniet amps, for example, put out serious current & are stable down to at least 0.5 ohm. so, if bridged, they'd still be stable down to at least 1 ohm, & wood still drive most any speaker.

re: your question regarding horizontal bi-amping, assuming identical amps, no difference in gain should be needed - the speakers' built-in x-over wood be seeing the same amp for all intents. but, i guess ewe could experiment... as far as needing active x-overs, again, ya won't need 'em w/identical amps. but while it sounds illogical to me, ral sez ya mite get even better sound if ya *do* use 'em - at least he did w/his maggies...

re: (c), this *is* where having a gain control on at least one of the amps wood be useful - different amps may have different gain characteristics, especially if ya wanna, say, run toobs on the top & solid-state on the bottom.

hope this helps, doug s.

Sean's answer is excellent overall, but the fact that you double the voltage applied to the speaker and therefore double the current (if the amp has the ability) through the SAME load accounts for the 2*2 times power. (*2 mean to the power 2, or squared).
I've heard recommendations from 'experts' for both Bi-amp techniques, as well as not even bi-wiring (to round out the ridiculous to the sublime). What I've heard, and I am no expert, is to bi-amp across (one multi-channel amp doing lowering amplification) another multi-channel amp doing the high side. Oddly, like getting two psychiatrists to agree which one is crazy, there are only questions, no dead correct answers.
Time for fairness. A question on another thread about stability/load rating when bridging made me realize the point of Sean's perspective on "effective" load impedance. While the two amps being in series with the same physical load does account for (up to) twice the current in the circuit, indeed each amp is supplying twice the current that it alone would into the nominal load impedance of the speaker. Thus, each is operating as though it were seeing an impedance half that of the speaker. If I may simplify (dangerous), think of the other amp as a negative impedance because it is supplying current rather than impeding it. My apologies for being focused on my point.