Bi-amping for me?


My new (used) speakers have this funny bridge between the terminals which I correctly assumed are for bi-amping. The dealer I boughtthe speakers from thought that I would get some added benefit from bi-amping. I'm going to ask a stupid question and please don't jump down my throat: do both amps in this scenario have to have the same output? The speakers run at 4 Ohms so can I assume that tubes would not suffice in either scenario. The speakers sound good with my present amp (threshold S300). Are there any articles you could recommend? Also would like some guidance with x-over units...From what little I understand, this is a controversial subject (i.e. the proposed benefits of bi-amping). Thanks.
russellrcncom
Hi Russel; do a search under bi-amp. I just checked and there are about 30-40 threads on bi-amping-- probably a lot of good info. there. I'll just say here that Richard Vandersteen recommends passive (no external X-over) vertical bi-amping as an improvement over just bi-wiring with his speakers. His owners's manuals say nothing about horizontal bi-amp.

I'm going to passive vertical bi-amp my Vand. 3A sigs. next week when my amps are returned from up-grading. As you note, this is a controversial subject, as for instance, you would have four separate amplifier channels driving four different sections of your speakers, and this has potential for introducing "unwanted colorations". Ideally, your amplifiers should be carefully matched to avoid these potential varying colorations. During up-grade, SMc is matching my DNA-2 amps, and I'm just hoping for the best. I just made the decision that I wanted to do it and proceeded.

I believe it was A71spud who was very pleased with bi-amping, especially when he used an external X-over. Good Luck. Craig
.....as to amps with same output. With a vertical biamp the amps must be as nearly matched as possibe, and therefore, yes, they must have the same output. In horizontal bi-amp, ie where one amp drives the upper frequencies and the other drives the bass, the amps can be totally different, ie tube amps for the mids/treble, and SS for the bass. But be aware that these are difficult to match, and I know I'm not ready for it. Again good luck. Craig
If the amps do not have the same output gain then you would have whatever boost the difference in gain is for the higher gain amps frequency push - otherwise you would need an external crossover to match the gains if that is what you want.Depending on the built in crossover some rooms benefit from non-matching amps to boost the bass frequencies a bit.
It sounds as if you might want to put a tube amp on the high frequency section of your speakers. This could work out fine as long as you match up the gains like Ligi has mentioned. You could take the higher gain amp (I assume the higher power one) and attenuate the signal with a passive pre-amp. (or just a stereo pot) This control would alow you to adjust the level for proper balance from the speakers.

And there is the ability to just bi-wire....

Chris