I have biamped before, with cheap Panasonic receivers and Sony speaker in a purely analog stereo configuration, which I didn't mind experimenting with. I now own a Harman Kardon AVR-240 and want to biamp my 7.1 setup in the most SAFE and efficient way I can. Before I buy the second receiver and another 200 feet of 12 gauge wire, I'd appreciate some input from you fine people. First, I'll lay out my system to help visualize the situation: Polk Rti-12 mains, Csi-3 center,(possibly a Csi-5 also, if I biamp) Rti-8 surrounds, as well as Rti-10s for the surround back channels. (should have gone with another set of the easier driven Rti-8s or surround bookshelf speakers, I know...they were originally my mains so I'm stuck with 'em) 12 gauge wire is all 'round, using gold-plated monster banana plugs.
Here's the deal: In stereo mode, sound is very rich with plenty of high, mid, and low freq. sound. 7 channel stereo mode is acceptable, although a bit flat. With true surround mode for movies, bass drops off dramatically and everything sounds washed-out. Obviously these differences are because of the vastly increased speaker loads, the processor's actions, and the Rti-10's four 7" woofers sucking current from basically non-bass producing rear channels. Since biamping is actually cheaper than buying a single receiver with twice the power, I'd rather face some technical issues and go with biamping.
Now, to the questions:
1: My DVD player (Philips DVP-642) has optical and digital coax outputs. I'm not going to split an optical signal, so that leaves me with either splitting the coax, or using both. I'm thinking of optical for the mid\high receiver to get more clarity, and coax for the bass handling receiver. Will there be a difference in processing times between the two receivers using these two different methods? I am not sure.
2: Am I able to use a moderately more powerful receiver of the same family, say the AVR-340 or 435, to power those ten 7" cones of the mains and rear channels or should I use another AVR-240? Would there be adverse effects on my speakers by providing them with the two different wattages? (50W and 65W) Remember these are conservatively rated high current "Harman Kardon watts", so they are actually much more powerful than these numbers compared to most other manufacturers such as Sony, Panasonic, RCA,etc....
3: Should I use one receiver for mid\high and the other for bass, or blend the two to balance the load? (such as using receiver #1 to power the lows of the mains, but the mid and highs of the rear channels and receiver #2 to power the mid\high of the mains and the lows of the rear speakers, and selecting the individual large\small "speaker sizes" accordingly)
4: The internal crossover freq. of the Rti-12 is 120hz. When biamping and consequently bypassing (I believe) the internal crossover, do I need to change the settings on my receivers, or do I leave them at 120hz? Is there a crossover between the mids and the tweeters (I am assuming there has to be) and would this dictate new crossover settings for the receiver handling those speakers?
5: Is there an advantage to using a different DVD player that supports 6 channel direct analog inputs, or is the combined channels of optical better or identical?
Thanks in advance for any input you may have!!