If you're willing to buy a refurbished receiver, this
Onkyo TX-SR703 would be a good choice. I've purchased 3 refurbished units, including a 703, and never had a problem.
If you felt you needed, or wanted, HDMI ins and outs, the
Onkyo TX-SR674 might satisfy. This is not a refurbished unit.
If you would be willing to spend a little more than your $500 budget, this refurbished
Onkyo TX-SR804 has it all.
I apologize if it seems like I'm an Onkyo salesman. It's just that I've owned Onkyos (and run M60s/VP150/QS8s with them), and feel qualified to mention them. I honestly don't care what receiver you end up purchasing as long as you are happy with it.
Biwiring and biamping are controversial subjects. Here is a
Biwiring and Biamping article by Alan Lofft, Axiom's resident expert. The cogent comments are, IMHO:
Biwiring - "
Will it sound any different if you biwire? Some users think it does, but I've never heard any differences, nor have any of our laboratory measurements or scientifically controlled double blind listening tests ever demonstrated there are audible differences. Axiom includes the extra terminals as a nod to those enthusiasts who believe that biwiring results in audible benefits and for the bi-ampers."
Biamping - "
Bi-amping, or biamplification, is used mainly in professional sound reinforcement applications, where extremely high levels of loudness are required.....but such systems have no place in domestic home theater systems in normal rooms. Additionally, it puts control of the relative smoothness and tonal balance into the hands of the sound system operator, a dangerous tool for all but the most experienced sound reinforcement experts."
