So setting up a BV7 Mark 3 with a 7-2, BL9 as front, a Passive with CX100's as Mid and BL4000 as rears.

What do I get if I add a centre rear speaker to this setup?

Good / Bad?

Cheers

I'm not entirely sure what you mean by "Passive with CX100s as Mid."  Are you saying you have two sets of rear surrounds?  If so, you will get nothing by adding a rear center unless you have a gigantic room.  Also, there are few Blu-rays that take advantage of a 7.1 setup.  Finally, if your surround processing is the BS3 you are only getting a matrix pseudo-surround in that other set of rear speakers.  So, unless you are in a really big room I doubt you would notice anything beyond a typical 5.1 setup.

Hi, instead of using Active speakers for the Mid, I've connected a Passive Amp (without the eye etc) and am using a pair of CX100's with each one configured as Left or Right Mid.

I could try another amp with a single passive speaker to see what happens....

I would suggest using the CX100s as the rears and using the 4000s for the surrounds. When playing lossless 5.1 blu-rays, the surround processor will not matrix the sound, which means that the rear speakers won't be used.

A. I agree with Jeff, that in your current setup, the BeoLab 4000s are being wasted. Switch with the CX100s for the best result.

B. 7.1 does not have a rear center channel, that's 6.1. I don't believe that the BeoSystem 3 decodes true 6.1 anyway and I also understand from some light internet work that it's even more obscure than 7.1.

Ok so are the BL4000's much better than the CX100's on an amp?

I must say they have never impressed me much at all.......

Also I'm guessing an external BR player (say PS3) will still make use of the Beosystem 3 for audio output?

I also found you it only lets you have a centre rear and not a left rear / right rear which only a single speaker.

So it's an extra feature that has no current use, or a bodge to stop you mis setting a single rear speaker?