In my case I will be running dual center channels from the 950. I want to know if I should run a y-cable from the one center output at the preamp to seperate amplifier channels or if I can just run dual speaker wire to the dual speakers, both of which would then be powered by the same amp channel. I know the latter will put more load on the amp.

Thanks in advance for any of your thoughts regarding pros / cons of alternate approaches.

It will depend upon the impedance of the speakers and the ability of the amps! If you are running a Krell with 8 ohm speakers you would have no problem. Keep in mind that speaker impedance varies with frequency! The best (safest) bet would be to run two identical amps, each running identical center channels. Best sonic balance would be achieved using one amp. The one amp approach would be better if the amp was a vacuum tube type (not as much concern for low impedance)!!! Be sure to set for 2 ohms, though!!!

you should have no problem running two 8 ohm spkrs in parallel which would give a combined 4 ohm load..there are very few amps today that would have trouble at 4 ohms. whether you use 2 amps is up to your budget. One side effect of using 2 spkrs is a smearing of the imaging which you may or may not like..it would be more pin point with one spkr I'm assuming centrally placed over the tube..with 2 spread apart between the main L & R the image will be more dispersed

No doubt I will need to experiment with this setup as I have not tried it yet. One of the things I do not like when I have the center channel speaker on top of the TV, is when you get the side to side sweeps I get this effect of the sound starting low on the side, swooping up to the center, and then coming down again. My front side speakers are floor standing JBL L5s. My center (if I choose to use as such) is a Boston Accoustics VR12. I have four L5s so I thought I would use the other two for a dual center channel and that way keep the sound in front level, and actually horizontally more even with the picture (in addition with the VR12 center on top is actually above listening level). On the downside the JBL L5s are rated 6ohms I believe so that will be a load if I run the dual center speakers off a single amp channel. Then I was thinking about getting another VR12 and setting the two of those up as rear surrounds. Kindof an unusual setup I guess but my room is not that big and I need to keep the back of the room open. You see the JBLs want to sit out about three feet from the wall to sound right. So another consideration, for the rears, I am wanting to go with something I can hang on the wall or a shelf, and get away from the floor standing L5s.

Just a couple ideas off the top of my head. Perhaps the sound difference is due in part to the speakers not being from the same mfr. The reason most people match speakers is for uniform sound. That could certainly be amplifying any geometric problems you may have.

Would it be possible to raise your mains? I haven't checked out JBL's site so I don't know how unwieldy your speakers are. Is it possible to position your center beneath your tv? Is the center above your head when it's on top of tv? Maybe try angling it down at your ear level.

Yes those are good suggestions and I will certainly want to angle the center down somehow if I go with one center channel speaker on top of the TV. I could not put the center under the TV unless I put it in front of the TV on a stand, angled up. I plan to experiment with that also. I love my JBLs, though, and they were designed as floor standing speakers. These were stereo speakers and not home theater so there is not a matching center that I am aware of. Being designed as floor standing they cannot be easily raised, and raising them may impact their sound I suppose. The VR12 is a real good center, as I have been through several, but I still prefer the sound of the JBL L5s. So I think these various configurations will have a hard time beating running dual L5s as the center, but I will need to test everything and see what sounds the best. If I had all speakers from the same manufacturer that would be best but since I own four JBL L5s I think the closest I will ever get to that is to run dual centers with two L5s as center and an L5 as left, and right. Then the back will be on something different but I think that will be the least noticable. I may be able to pick up some JBL L1s or L3s that would work in the back in the VR12 is not suitable for that application.