Bi amping speakers

For most speakers, you need less power up top. Ribbons are an exception, especially like mine, which cross at 150Hz.

Two more questions:

1) Generally does driving the bass with 133 wpc and the highs with 100 wpc provide better sound than just driving the entire speaker with 233 wpc? Or, does it just provide better sound than driving the entire speaker with 133 wpc? Sorry if this is a stupid question, but I have run into some forums that say that bi-amping does not double the power to the speaker and, thus, is a waste of $ - or at least the returns are not extensive enough to justify the $. Afterall, I could also just use my 806x for five channels and sell off my 405 if the difference of bi-amping is not that great.

2) Does bridging an amp create significant distortion? Again, I have seen forums that suggest this. If this is a problem, would it be more so if I bridge the 806x for the entire center channel than just for the bass?

Two more questions:

1) Generally does driving the bass with 133 wpc and the highs with 100 wpc provide better sound than just driving the entire speaker with 233 wpc? Or, does it just provide better sound than driving the entire speaker with 133 wpc? Sorry if this is a stupid question, but I have run into some forums that say that bi-amping does not double the power to the speaker and, thus, is a waste of $ - or at least the returns are not extensive enough to justify the $. Afterall, I could also just use my 806x for five channels and sell off my 405 if the difference of bi-amping is not that great.

2) Does bridging an amp create significant distortion? Again, I have seen forums that suggest this. If this is a problem, would it be more so if I bridge the 806x for the entire center channel than just for the bass?

The answer to 1 depends on how you are bi-amping. If you have an active crossover in front of the amps to divide up the frequency spectrum, bi-amping is always better if you have enough power (but you need less that not bi-amping). If you are going to amplify the entire spectrum and have the internal crossovers divide it up, the answer is probably indeterminate. It will vary based on what you are listening to (i.e., from disk to disk). What will happen is that you will share power from channel to channel within the same amp, but you are still wasting power by amplifying the entire spectrum to use only a part of it. This is offset by typically not having enough power, but you could with the 806 just go bridged and get 360 without bi-amping.

That said, bridging does affect the sound, IMHO. Bridging the bass isn't as bad as bridging the treble. I think what makes bridging sound bad to me is just slight timing differences as the signal goes through all those components on both channels and are combined back together. It's like jitter. There seems to me to be a little smearing that you won't notice in the bass as much.

So, you do have a choice. But the answer to 2 is yes, depending on your definition of "significant".

Thanks. That is helpful. I am planning on using the internal crossover of the speakers, but the speakers (B&W Matrix 805s) do have dual posts, and their literature says they are made for bi-amping. I guess I might as well try some different configurations once my 806x comes back from the shop.

One more quick question for anybody who has used the 806x - It has inputs for every channel as well as inverted outputs. The manual says that these are generally used for bridging. My question is whether they can also be used for bi-amping. If I am using my 806x to drive the bass in my speakers, can I use these inverted outputs to my 405 channels to drive the highs? Or would this effectively bridge my 806x to my 405?

Not sure exactly what you are asking here. If you mean you want to take the inverted output of an 806 channel and combine it with a 405 channel, the answer is NO, that wouldn't be a good idea. For one thing you are combining channels from separate chasses, and you really don't know the orientation of the signals. Furthermore, one channel would have more power than the other. And, even if you got the signal orientation right, propagation of the signal through the amplifier could be different (more components in one, etc.) putting the signals slightly out of phase.

Thanks - I think I understand. I was just trying to figure out how to bi-amp the two given that "Y-cables" may not work since the inputs for the 405 are all over on the back right side and the inputs for the 806 are all across the amp. I guess the inverted output will not work to share the processor signal for each channel since it sounds like it would bridge the two amps, which, as you said, would be a bad idea.

You can feed the same signal to both amps with a Y cable. It's what you do with the outputs that matters. Don't connect them to the same binding posts of a speaker.