Sat -
I'm looking forward to the audition Wednesday and hope it works out with your schedule. Here is my advice ahead of the listening session.
First, info on my setup:
My room is considerably smaller than yours. It's roughly ~2400 cubic feet and my main listening position is ~10 ft from the front speakers. The Denon 3808 powers a 7.1 Epic 80/600 setup and I also have a second Earthquake SuperNova sub to even response in the room (an older sub that I kept when I upgraded to Axiom).
Even though the Earthquake doesn't get nearly as deep as the 600, it does contribute greatly to flattening response in different listening positions, so any of the options above should work in your room too (2x600, 1x600 + 1x500, etc.). Incidentally, I've heard the 500 as well and was very impressed with it, but it doesn't get as deep or as loud as the 600 can.
When you're here I can show you some of the work I did on flattening response in my room when I had one versus two subs. In a room your size though, I'd strongly agree with the suggestions to look at 2 subs (either now or as an eventual upgrade). If money isn't the main driving factor for you, I'd say go as big as you can (i.e. 2x600). Having said that though, I believe you'd be happy initially with 1x600 plus another 500
or 600.
Also, there's no reason you can't start with one sub now. Even with one sub you should be able to get very good bass in your primary listening position (assuming you have some flexibility on placement options for the 600), but the rest of your movie-watching friends may not get quite the rumble you do with only one sub running.
Back to your other questions on amplification...
Even though my room is quite a bit smaller than yours, definitely wait until you've listened to my setup before you spend too much time stressing on power options. I am constantly amazed with how much volume the 3808 can drive out of the M80s. Even in a long room, given how efficiently the M80s run, I believe you'd have to be someone who regularly listens at fairly extreme volumes to completely take advantage of the power of separates.
While you're considering whether you need separate amplification, consider the
amp power calculator here. As an example, let's say in your large room you sit ~20' from your speakers and want to be able to listen at average volumes of 90 dB and allow for peaks of 10 dB (which sounds twice as loud as 90 dB). This requires less power than you might expect... ~114 watts per channel, which the 3808 is capable of. Also keep in mind that after ~2 hours listening at 90 dB, you risk permanent hearing loss, and after only 15 minutes at 100 dB (both of these are approximates as not everyone agrees on exact exposure limits). Either way, however, 90 dB with 10 dB peaks would be listening fairly loudly.
With all that said, you may like to listen much louder and can use the calculator to give yourself an idea of what you'll need. Variables like the location of your main listening position can change the required output significantly, so it's a good way to give yourself an idea. Regardless what the calculator says, try it first without separates and see if you can make your ears bleed without more power.
I suspect you might be surprised. As far as choosing one receiver over the others, I'd make the choice entirely on features and connectivity and avoid making power a determining factor. If you'd get a lot of use out of the Rhapsody streaming service, I'd say that's a big plus versus the others that do not allow this.
If I was in your shoes and was choosing where to put my money first, I would start without extra amplification and put the money saved into a second subwoofer. I believe you'd hear the difference of that upgrade much more clearly and much more regularly than you would if investing in separate amplification, which would help, but mainly when pushing the system extremely hard.
To your question on cables, you can also save a boatload by bypassing the marketing hype on "high quality cables." Most of us here have been watching various research studies comparing high-cost and low-cost cables and have continuously seen that Monster speaker cables never produce results that are audibly discernible from any other cable. (while a machine might be able to measure differences in the signal, human ears cannot)
My whole system is wired up with cable from either Monoprice.com or BlueJeansCable.com (so I can agree with both of the previous posts highlighting the quality of either). I'm happy to talk with you at greater length about this when you're here... Lots of first-hand stories that make for interesting data points.
In the meantime definitely let us know if you have more questions.
Jason
