[josh358]

The folks advised me that one pair of their QRD diffusors was sufficient for Magnepan 1.7s and advised 2 pairs for Magnepan 20.7s. I didn't see what your speakers are, but this should be helpful as a guide.

I use two since I had planned to upgrade to the 20.7s, but this has been postponed (shelved really).

Were these their 2 x 4 wooden diffusors, or the 2 x 2 plastic ceiling diffusors?

[jk@home]

The folks advised me that one pair of their QRD diffusors was sufficient for Magnepan 1.7s and advised 2 pairs for Magnepan 20.7s. I didn't see what your speakers are, but this should be helpful as a guide.

I use two since I had planned to upgrade to the 20.7s, but this has been postponed (shelved really).

They are modded MMGs, 50" tall. I planned on also placing diffusors on the walls, close to the inside edges of the traps, where one would see the backs of the speakers if looking into a mirror on the back wall, from the listening chair.

So I am looking at 4 or 8 (or more?) - 2x2 panels, depending on the amount of diffusion required.

[medium jim]

I'm probably all wet on this one, but I try to keep it clean behind the panels and only have some absorption behind them, mostly behind the ribbons. This seems to work the best for me, but again I may be all wet....

Jim

[dm]

I have been happy with the GIK QRD's behind my magnepan 1.6.

see here:

http://www.audiocircle.com/index.php?topic=96511.msg978891#msg978891

[rw@cn]

Were these their 2 x 4 wooden diffusors, or the 2 x 2 plastic ceiling diffusors?

These: http://www.gikacoustics.com/gik_qrd_acoustic_diffusors.html

[josh358]

These: http://www.gikacoustics.com/gik_qrd_acoustic_diffusors.html

OK, so they were the full sized ones. Did they suggest, when used with the 20.7, putting them on top of one another for 8' tall diffusors? Or side by side?

[rw@cn]

Side by side. Here is an older picture before I install corner bass traps, mye stand and cleaned up the wiring.

[josh358]

That's interesting. I suppose that's because of the width of the 20.7's, although most of that is woofer and I wonder whether the diffusors even do anything at those frequencies.

[rw@cn]

I had 3.7s in that same space and briefly tried using only one per side and thought that 2 per side was better. For some reason, I have not experimented with the 1.7s.

[josh358]

Interesting. I hate to think what that means for my Tympanis . . .

[berni]

Side by side. Here is an older picture before I install corner bass traps, mye stand and cleaned up the wiring.

is there a Pathos InControl preamp? I have one as new for sale(2100 eur) )

[rw@cn]

Yes that is a Pathos preamp. I just replaced it with a Pass XP 10. I wanted the XP 20 but couldn't quite stretch the budget that far. I'll be putting the Pathos on the market in a few weeks. I haven't decided on the price yet.

[berni]

How would you define the sound, very detailed, transparent and wide, but a bit thin on the low end so bit weak for planars..

[bpape]

I'm actually doing a room for a customer right now that is doing 5.1 system with 20.7's.  We're using 4 of the Q7D's behind each of them - 2 wide and 2 high. 

Bryan