BIAMPING

sfrounds,

if yer speaks are truly bi-ampable, and ya *do* have two identical amps, the best ting to do is yust try the 3 different methods - bridged, wertical, or horizontal bi-amping. it's easy to tell if yer speeks w/two sets of binding-posts are *really* biamp-able: yust hook one amp to only one set of binding-posts w/o the yumper in place, and only that driver should play - the other should be silent. (but, it's hard for me to imagine why a speaker mfr wood have two sets of binding-posts, if all drivers play when only one is used, w/o a yumper).

i have had good luck horizontally biamping w/an electrocompaniet aw100 driving the woofs & an aw75 driving the tweets of my monitors. but, yust this week, i sent my aw100 to a guy who wanted to trade his aw75 for a bit more power. his aw75, w/serial # only 5 digits away from my aw75, should give me the perfect opportunity to try bridging & wertical bi-amping, as well as horizontal bi-amping. i also have a pair of gnu aw60's, bought from europe, waiting for me to conwert from 220 to 120v. (i had given up on finding an aw75, & the trade offer happened shortly after i bought the aw60's!). so, i may also try bridging all 4, so each driver has a mono amp. but, this may really be over-kill in my system, so i may end up using 'em in another system, trying to sell 'em & use the money for a pair of melos mono-toob amps, or...??? ;~)

re: ral's suggestion of using an active x-over, i'd recommend this *only* if ewe can completely bypass the speakers' internal passive x-over - i wood *not* use an active x-over *and* the the speek's passive x-over - this is sure to muck-up the signal, imho. and, an amp run to one set of binding-posts of a bi-amped speaker only sees the the load above or below the speakers' passive x-over point, anyways...

good luck, doug s.

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.