Bi-amping, "What amps would you use"

There is no easy answer... the way that the signal is split also plays a role; is it an opamp xover, tubes or what? This is a critical component. It also matters what the system sounded like to begin with.

IMHO, if there is a big advantage to bi-amping with a system like this it is that you *might* be able to finess a bit of the overall sound by employing amps with suitable characteristics for each range. It would seem like the ideal for this system if it could be tri-amped and if that was the case I'd opt for a set of very clean, and well done p-p 300Bs for the tweets. Depending upon how the bass sounds now, you might opt for finding an amp that happens to have the right "sound" for the room and your ear in the bass region - you can't do that with a full range amp, unless you get lucky. Then in the mids, you'd look for something that is kinda clean, mid power range and dynamic...

The interesting part of bi-amping or tri-amping is that an amp which would otherwise be awful for full range operation *can* be simply marvelous when applied in a limited bandwidth application.

The fact of the matter is that name brand means next to nothing for this... performance does.

Greetings Dan, I am bi-amping a pair of KEF series 3-2 speakers. The back of the speakers have two seperate sets of connection posts for this purpose. For the top half, which is dedicated to mid's and high frequency, I utilize a Conrad Johnson Premier 11 tube amp. Tubes just can not be beat by soild state or FET in mid to high range. Now, for the low/bottom, or bass frequency I utilize a Conrad Johnson MF2250 FET (field effect transistor) amp. FET's are hard to beat for bass frequencies. I am VERY HAPPY with this set up. What ever you do, I recommend you stick with one manufacture of amplifier, and discuss your intentions with them, if possible. There are "issues" to be concerned about when bi-amping.

Regards, Lou

Sean, wow -- so cumulatively speaking, that makes it penta-amping at full home level...:) I barely manage the bi (amping, I mean) -- plus both are stereo units at that!

Actually Greg, i would be "dodeca-amping" as i have twelve active channels being driven. To make things understandable, i have six stereo amps set up as monoblocks with all 12 of their channels being used. In other words, i have both channels of Amp A driving the left tweeters, both channels of Amp B driving the left mids and both channels of Amp C driving the left woofers. There is an identical set of amps ( which would be Amps D, E & F ) set up the same way for the right tweeters, mids and woofers. Even though i am using both channels of each amp, they are still only seeing a mono signal ( left or right, but not both ).

I've done it this way as i have multiple low impedance drivers in each frequency range. By splitting the drivers between multiple channels, i've reduced the low impedance load on each amp and increased the available power for each frequency range. In effect, none of the amps are pushed as much, they operate in a range that is Class A for the mass majority of time, damping is improved, dynamic headroom is increased, etc... to top all of that off, using the "monoblock" approach offers the ultimate in channel separation.

As Bear mentioned, i chose amps that i thought excelled in specific frequency ranges. Getting everything dialed in and gain matched was a "bear" to say the least : )

The drawback to all of this is that i have more cabling in this system than what most audio shops have in their demo rooms i.e. twelve interconnects from the active crossover to the inputs of each amp channel and twelve sets of speaker cables. Needless to say, it is next to impossible to make this installation look "clutter free" :( The fact that i'd like to move into a bigger house sometime in the near future does not make me happy either :( Sean
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Sean, you just blew me out of the house! Indeed, this looks (and probably sounds) like an ultimate system i.e. taking available products & implementing the most sonically efficient set-up... bending the limitations of the products to serve the system sonics.
Another A'goner has a similar concept, it seems, with a different approach: being discontent with the reproductive range of speakers (i.e. none satisfied his ear as full-range players), he relegates part of the output frequency to the "appropriate" speaker -- hence a speaker or "sound-wall".

I would assume that your primary limitations now can only come from speaker drivers & cables. (I discount digital source technology because we can't control that other than tweak the cdp's a bit -- we can't change the s/ware).

Impressive! Proof that it pays to be a music-phile & an EE at the same time!