Just wanted to say thanks to mech for bringing my attention to the 107's in Northern NJ...they are now mine!
In a few months I might be pulling a "Simply Sound" and using my 103.2's as a center channel in a home theater setup...
Alright!!! Thanks to Barty-Brett for leading you onto the R107's... you my dear Hawkeye have made one great purchase there!!!
OK, I agree with Frommer, you will want to use the Pre-Amp Out capability to drive a dedicated amp for the R107's. I myself have both my Mains (R107's) and my Surrounds (IMF TLS-50's) driven with separate amps.
I'm running the R107's on a McCormack DNA-0.5 right now while my DNA-1.0 is being serviced. It is a 100W/8ohm Amp that probably is close to 200W/4ohm. It drives the R107's just fine. The big KEF's of course can take power (300W) and they probably respond to the "more is better" approach.
My DNA-1.0 is sized for these speakers at 150W/8ohm and 300W/4ohm. But the R107's are also pretty sensitive so I find there's plenty of detail with the 100W DNA-0.5.
Now, I use an AVR for all of this because I'm BOTH a Home Theater and 2-Channel guy. That is what is nice about an AVR, you have flexibility AND Room Correction (Audyssy).
I run an NAD T775 and if I want to listen to "Stereo", I can just run the big KEF's or if I want to enjoy my IMF's, I have them positioned so I can run Stereo just through them. Best of all worlds, because surround with all of this is really amazing!!!
And since I'm on a roll, I actually like the IMF's for 2-Channel better than the KEF's because they have a certain richness to them, whereas the KEF's tend to be a bit analytical or should I say just a bit accurate!
OK, on to the center channel... The only thing my NAD is driving is the center channel and a single rear speaker (yes, an R107... think triangulation). It's interesting, but I don't think any of the AVR Manufacturers rate their amps for driving 4ohm loads.
Why? Well probably because they think that everyone will be driving all 5 or 7 channels off the thing and they don't want folks burning them up. So to protect themselves from warranty issues they don't recommend it.
I have my R103.2's setup in parallel and yeah, they are probably drawing 4-5ohms (these aren't 4ohm rated, they are 8ohm). Does it heat up my amp? Probably no more than if I was running all of my channels at 8ohms.
So no, I wouldn't be too concerned about the center channel in parallel if you are driving your mains (and maybe surrounds?) off a separate amp. Just monitor the heat when you get things running and if it seems fine, you'll be fine!!!
One last thing, when you position the R103.2's together place the woofers next to each other (bottom-to-bottom). I have experimented with both orientations and I've found the voices are mostly carried by the woofers. If you position those together, you'll have good cohesion. I myself have noticed no issues with "lobing"!
And one last-last, thing... the R103.2's are near perfect for this application. They are true "near field monitors" that were designed for voice representation... I have tried a dedicated B&W Center Channel Speaker and found the voices just too thin. The R103.2's have a certain depth and volume that a dedicated Center Channel Speaker just can't match!!! Doesn't get much better than these in my book!!! Then again, not everyone reads my book!!! :thmbsp: