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
There are some speakers which actually sound better if you use an active xover to externally separate the bass from the mid/hi (prior to the amps), then let the speaker's internal passive
xover split the mid and hi's within the remaining signal. E.g. the larger Magnepan speakers (I
own and biamp the MG3.6 in just this manner). Also, you certainly don't want to run a full-range
amp signal into each individual driver of a biamp-ready speaker; this would send high-freq. info.
to the woofer, and bass info. to the midrange/tweeter, which could cause distortion or
damage the drivers.
ral, there should be no problem w/running a full-range amp signal into each individual driver of a biamp-ready speaker - it wood *not* send hi-freq info to the woofer & bass info to the mid/tweet, unless ewe also went inside & disconnected the passive x-over, but why wood anyone do that, unless they're using an active x-over before the amps?

it's interesting hearing your success w/using *both* the passive x-over *and* an outboard active x-over w/yer maggies - i guess this is yust another example of what seems logical on-paper isn't always best in the real-world. i guess ya yust gotta experiment! ;~)

regards, doug s.

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).