Denon 5308 vs Yamaha Z11 - I think they are pretty much identical in terms of audio & video performance. But if I were judging, I would give the Audio specs to the Z11 and the Video specs to the Denon. So I would actually favor the Z11. However, since I'm a Denon guy, I would still pick the 5308. Pure personal preference and nothing to do with performace differences.
Yes, at one point I was actually Tri-amping the CLR3000 using 3 Acurus RL11s and an Acurus 200X3 (200 wpc x 3 ch).
The RL11s had dual L+R Outputs. I had to use one Y-splitter cable. So it then gave me 3 Center Channel outputs. These fed into the 3 channels of amps and fed to the 3 speaker terminals of the CLR3000.
It's "fun" to do and look at, but I don't think it does anything for performance.
Okay, on the BP7000SC, it's labeled "LFE In". On the CLR3000 it's labeled "Full Range Low Level In". Thus, you can hook the Subwoofer output to the BP7000SC, but NOT to the CLR3000. You would feed the CLR3000 a Center Channel Preamp Output -- if you want to. However, most people don't. I don't.
So now I just use one speaker wire for the CLR3000.
With my Denons, everything is set to Full-range 20 Hz - 20 kHz. Def Tech actually recommends the SM450s be set to Large as well.
I'm sure the "Night" is still "Young" for speaker auditions, but I still have NOT heard anything that would make me want to give up my BP7000s.
In fact, I'm planning on selling my CLR3000 Center and BP7001 Surrounds so that I can get 3 more BP7000SCs to make 5 identical BP7000SCs + the Trinity.
And then I'm planning on using 5 Y-Cables to create 6 Subwoofer/LFE outputs to feed the 5 BP7000SC + Trinity = 6 subwoofers.