4000's are much better! It's simple!

A agree, between these two speakers, I would always go for the Beolab 4000

If it is not a question about design and placement, but only about sound, then you should to for the BL4000.

I previously had a surround setup with BL6000 as front, Avant as centre, BL4000 as rear and a KEF subwoofer. To my ears the BL6000 and the BL4000 sound almost the same. I even tried to switch them, and there really isn´t much difference in sound. The design of the BL6000 is absolutely wonderful, but if it´s a matter of where to place them of course the BL4000 is extremely flexible. 

Both are great speakers, and you cannot make a wrong choice.

Soundwise the Beolab 4000. The single (but larger) bass driver sounds clearly better than the double bass drivers on the Beolab 6000.

We have two pairs of 4000s and a pair of 6000s.  Both have excellent sound of course. I tend to prefer the 6000s. Have one pair of 4000s in storage, one pair connected to our iMac and the 6000s are in our living room.

I like them both! But if had to choose between them... 4000! Better sound, look great, and better placement options.

Curveball: How about a pair of BL3000/4500/5000? I like them for a link room as they have displays!

I have owned a set of both and the BL 4000 I think are over all a much better speaker than the 6000's. I honestly do not think the 6000 are as bad as some people say but I think they NEED a subwoofer because their bass resonse is pretty bad. BL4000 are better balanced.

I'd say the BeoLab 4000 just pip the 6000's to the post.  I wouldn't say they were miles ahead though, but the 4000's just seem to have a little bit more 'punch' and depth in my opinion.

I doubt that in a link room you'd be disappointed with either. 🙂

Lee