bi-amp question

hwu56

I am a newbie and have never done bi-amp ...
I have a 7.1 setup. Using Carver m-1.5t to power 2 front Rti12. Using B&K AV6000 (100w x 6) to power 1 center and 4 surround speakers. My center is Cambridge MC500 (about the size of CSi5) and is currently bi-wired.
My question is: since I still have 1 extra channel on my AV6000, can I use it to bi-amp my center?
If yes, how?
I am thinking of connecting Y adapter to center pre-out of receiver, and then run 2 IC's from Y adapter to 2 channels in AV6000, and then use those 2 channels to power the center speaker. Is this correct?
Also, considering the extra cost of the cables ( I use Signal Cables for all connections), is it worth it?
Thank you!

hwu56

oh, I just realize that I can run 1 IC from pre-out to Y (1F -> 2M), and connect Y directly to 2 channels in amp. That way, I can save 1 IC.

But that's assuming I can use the 2 channels in one amp to bi-amp the center speaker. Is this a good idea?

John K.

H56, no you can't actually bi-amp in the way that you suggest. The "extra channel" in your AV6000 is connected to the one power supply that the amplifier has and doesn't have any power of its own. Feeding the same amount of available power into a speaker by funnelling it through two sets of output transistors(one previously unused)rather than one can't double the power or increase it in any amount. Real bi-amping requires at a minimum two separate amplifiers(not just separate channels in the same amplifier)and for best results also requires removing or bypassing the internal speaker crossover and using an external crossover to divide the frequencies before the two amplifiers.

dorokusai

Wouldn't a crossover that is set up for bi-wiring already be wired with seperate paths for the high/low even though they run on the same board? Why does it have to be an external crossover to be true bi-amping? Isn't the amplifier statement a bit broad to cover all designs commercially available?

John K.

Sure, Mark; all crossovers, regardless of whether the speaker has two sets of input terminals, have to have separate paths in the crossover to feed the low and high frequency drivers, otherwise no "crossover" could take place. The external crossover can be designed to have lower power losses than the internal crossover and would send each of the two separate amplifiers only the frequencies that it was necessary for that amplifier to carry(if the crossover preceded the amplifiers).

If a unit had two complete amplifiers, including a power supply section and an amplifying section of output transistors for each amplifier, then it would be two amplifiers rather than one, even if everything was in the same enclosure.

dorokusai

John - I think we're looking at it from two different angles but I get what you're saying. What would be the benefit of just sending the "proper" freq's to each respective pair of binding posts? as opposed to it being full range and sorted out internally? Aside from it being a more "purist" approach to signal transfer.

A dual mono design is what I had in mind in regards to amplification. I don't believe that design, for example, would be lacking in power supply capability in contrast to using the spare, unused channel of an AVR. Of which I agree, is pointless and not bi-amping in my world.

hwu56

Thank you guys. I think it is my misunderstanding.
I was always thinking -- since the amp spec says 100w x 6, I can use one channel to power the "high" of the center speaker, and use another channel to power the "low". Looks like I was wrong ...
How about this -- can I use one channel in amp to power the center "Low", and use my receiver's regular center speaker output to power the "high" ? Will it cause any damage?
Thanks.