Quick update on my C-100/C-C100 system.
I picked up a new Yamaha RX-V465 AV receiver yesterday from our local Ultimate Electronics. I bought it without reading any reviews, something I don't usually do. It was brand new to the store (only up for about 24 hours). It's a 105wps 5.1 receiver that has Bluetooth, DTS HD Master Audio and Dolby TrueHD decoding, as well as 4 HDMI inputs (with audio delay). It also has independent remote selection of inputs. At $330, I was prepared to have to take it back. Surprise! I like it a lot.
My Orb sub problem turned out to be a dead sub. Buddy of a buddy is taking a look at it for me. Fortunately, I had two. The other one went into the room with the C-100s and the new C-C100. The Yamaha has a 7.1 stereo listening mode that I really like for music. I threw a ton of stuff at it today, and it's a much sweeter sound than the 5-6 year old Pioneer receiver I had running the Energy's before. Part of it is probably that the Energy's just keep getting better as I put more hours on them, but the Yamaha is a significant improvement, especially on the high end.
As I suspected, the C-100s and the Orb 8" sub are a potent combination. The Yamaha also has a YPAO auto EQ system that tames the bad acoustics somewhat, though I still have a lot of work to do to mellow the 11x11x8 plasterboard room.
Thought I'd share my limited experience with the Yamaha receiver, since I know some folks here are looking for one to go with their new Energy's. For such an inexpensive unit, it's really surprised me. It's not 7.1, and it doesn't have any video processing, but it's just what i was looking for for this room. It's a bargain, too.