bi-amping basics

many have reported that bi-amping is the way to go if your speakers allow for it. many ml speakers do, but very few pre/pro's have dual outputs for front l/r. so my question is this: why does bi-amping sound better? does it use the speaker's internal crossover? would using a sufficiently high powered 2 channel amp have the same effect if i use 2 runs of speaker cable per speaker? btw, i have ascent i's with pass x350 amp. option to bi-amp would be using 2 pass x250 amps. thanks and sorry for beating this topic to death.

I'll throw my 2 cents in. Do you mean bi-wire or bi-amp because there is a difference. Bi-wiring is from the same amp with two sets of outputs and cables where bi-amping is two separate amps.
I used bi-wiring on my Sequel II's and there was a difference. My amp has two sets of outputs. It was a bit more "refined" in the sound and a bit more seemless between the woofer and the panel. It seemed that the low mids from the panel were better defined and that the upper mid/bass from the woofer seemed better. I guess a bit cleaner, effortless, throughout the frequency range too, would be more acurate.
Using two amps will present two different signals (levels) to your Ascent i's. Neither amp will really work that hard because they are dedicated to a smaller frequency and impediance swing, there by, disapating less heat and working less. There are some here that use a solid state amp for the woofer and tubes for the panels. (cool!) The only caveat is that you have to be able to balance the volume between the two different amps. There are attenuators (kits?) out there that can accomplish this at a reasonable cost.
I would try bi-wiring first since it is cheaper, if you amp can do that. I am not familiar with the Pass but others are here and can advise better. See if you can borrow an amp and it does not have to be a powerhouse to drive the panels for about a week or whatever to see if you hear a difference.
The real key here is if you can hear difference and is it worth the money. Of course there is always the WAF to deal with too

Good Luck

Jeff

Here are a few links to bi-amping basics:
http://sound.westhost.com/bi-amp.htm
http://www.audioholics.com/FAQs/biampingvsbiwiring.php
http://www.audioasylum.com/audio/general/messages/57210.html

Most good (audio) preamps have 2 sets of outputs to facilitate bi-amping. Given that your question is regarding pre/processor units having only 1 set of outputs for l/r channels, you can get around this problem using a Y-splitter. I like the ones from Monster Cables since they don't involve any runs of cabling to degrade the signals.
http://www.monstercables.com/productPage.asp?pin=655

Specifically regarding ML products, I was forewarned that the crossover circuitry is very complex and an integrated part of the transformer circuitry for the electrostatic panels. Given this warning, bi-amping ML my reQuests speakers using electronic crossover will just add more circuitry into the signal path, negating the benefit of active crossover. I opted to "passively" bi-amp my reQuests in order to keep the signal path as clean as possible. There are ML products designed to be used with an (supplied) electronic crossover and my comments don't apply to those.

If you already have Pass X350, it is a VERY respectable amplifier for ML already and pretty hard to improve upon. Without knowing what your goals are, I cannot recommend tubes over the Pass. For myself, tubes on the panels + solid state on the bass provide a wonderful match.

Good luck with your system

Spike