BIAMPING

I want to thank you guys for this indepth education (especially you Sean). I've read over all your post several times, and I think I get it. However I have some clarifications and a final question.

Given that I have these two identical amps, and lets say I have speakers that are bi-ampable.

(A) I can vertical bi-amp without any modifications, and do not have to use any active x-overs?

(B) I can configure both amps mono without any modifications, however, I should have speakers rated at 8 ohms (which are really 4 ohms when using amps mono blocked?

(C) If I wanted to horizontal bi-amp, I could use these two identical amps or one smaller amp for the mid/high frequencies.

My question regarding horizontal bi-amping is; My duplicate amps have gain controls, is it necessary to use active x-overs? Can the gain control on the mid/high frequency amp be adjusted to achieve a match between the the low frequency amp?

PS - Remember, I did say I think i get it!!

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.