It's a good pairing so the question isn't whether or not its good. In fact it's a great option for a multichannel setup. If you got a grea deal on the combo don't look back and enjoy. Only if you feel something is missing or isn't right should you then explore other issues or preferences with other components. Speakers---the ones you are using---will be the critical factor.
While not having the latest & greatest version of Audyssey, the AV7005 is still an excellent pre/pro and combined with the MM7055 you are considering, you would be hard pressed to find an AVR that would match this combos performance for your $1500 investment.
The only thing you need to watch out for is the impedance of the speakers you purchase. I don't believe the MM7055 is rated into 4 Ohms; only 6 & 8. So make sure the speakers you select are 6 or 8 and you'll be fine as the amp generates plenty of multi-channel power to get the job done. So go for it and you'll be on your way to a great HT system.
Bi amping has benefits. Without doubt, it certainly has theoretical benefits - an active x-over ahead of the power amps will generally produce better distortion and phase performance. Further, offloading deep bass to a subwoofer will likely increase any system's max clean SPL capability, but....
You're already bi amping this system when you add subwoofers. By bi amping the mains, you're effectively tri amping the system. While there may well be additional benefits to this approach, I'd agree that this is a low return on incremental spending.
Those theater amps you are considering from Marantz are not among their better amps. Any amp that can't handle 4 ohm speakers is no better than the amps in a mid level receiver, although the 8003 has better specs. I'd suggest amps from companies such as Outlaw Audio(model7500), or Parasound.
I assumed the OP would use the bass management in his pre-pro, so he will almost surely get the benefits of bi-amping there. (No REL style, high level crossover set-up to argue about in this case).
My comment re: low return on incremental spending was reflective of the OP's stated intention to add a second power amp to his system to "bi-amp" the main speakers. In all likelihood, that would fail to achieve most of the benefits provided by bi-amping, anyway, since the crossover remains in the wrong place. As to the superior cost benefit tradeoff for the proper biamp arrangement in most powered speakers, I'd defer to those who know the market better. That includes lots of folks out there; Bob among them, for sure.
My sn was randomly generated by Audiogon. My name, Aman, plus some random letters/numbers. Not so random after all.
To be clear, this will be my main setup in a tri-level condo with walls that I technically don't share with my neighbors, as there is a 1 inch gap, but for all intensive purposes, I should just assume that noise will permeate through them quite easily. The room is rectangular and deep enough to warrant a good setup, but I really don't have room for 2 subs.
I could get a better amp later, I had a parasound before. But for now, I don't mind going with a good enough amp/pre setup as I have to still buy the rest of the setup, including center, surrounds, interconnects, power conditioner, etc etc.
I would like to read the white papers you mentioned. IMD is definitely a concern that would be more pronounced in the 8 channel amp vs the 5 channel. I also have never purchased active speakers. I prefer vienna acoustics Beethoven or b&w nautilus speakers. I also hate that humming noise that systems often generate and I feel my not having active speakers, I get rid of additional culprits that would cause that irratable hum.
Btw, you guys are immensely more knowledgable about all this than I. So I appreciate the information and am enjoying learning from you.
My negative comment on biamping is based on the assumption that it will be accomplished in the most common and least effective way: feeding a full-range signal to two amps which are wired to the two pairs of terminals on a speaker with an internal non-active crossover. That is the type of biamping that is offered by AVRs and (most) prepros. It is also to be distinguished from the biamping involved in bass management and, I believe, the OP was not equating the two.
I do acknowledge that biamping using an electronic crossover feeding amplifiers wired to speaker drivers (and what is found in active speakers) has definite benefits. However, the uninformed associate those benefits with the more common biamping described above.
Aman4kr4, I think you have two great amps at a great price;
Two years ago I bought a Marantz SR7005 - the top-of-the-line av receiver at the time; I bi-amped the two front main channels (you can configure the SR7005 to do that if you're not running 7.1) with my B&W 805's, and it sounded wonderful.
I've been bi-amping systems for years now, and in my opinion, the sonic improvement is quite real. I would heartily encourage you to do it, and enjoy your two fine pieces of equipment.