GIK Diffusers

rw@cn · « **on:** 14 Jul 2011, 04:43 pm »

I originally asked Brian a few question about the GIK diffusors in another topic thread and belatedly realized that I was off topic so started a new topic here. I asked Brian to explain the differences between the diffusors. Here is his answer.

Quote from: bpape on 14 Jul 2011, 04:11 pm

All of the diffusers except the Grid Fusers are single period diffusers. The Grid Fusors are 2 mirror imaged 13 root diffusers in each panel. The other diffusers, if hung in pairs, need to be hung with 1 inverted from the other to avoid repeating patterns which can cause comb filtering.

The other 3 are all 7 root diffusers.

The D1 is hollow and can be filled with insulation for a tad of midbass control in addition to the diffusion. They will reach a bit higher due to the poly's on the tops of the wells.

The QRD and Q7D have the same size wells. The QRD is an EPS core with a wood frame - no dividers between wells. The Q7D is all wood and has dividers between the wells for a bit smoother diffusion pattern.

The optimal for behind 20.1's would be 2 Q7D's behind each panel as a mirror imaged pair with a gap between them the size of one of the wells.

Bryan

rw@cn · « **Reply #1 on:** 14 Jul 2011, 04:45 pm »

Brian,

Would I need two behind each 1.7's. This would save a bit of money and still leave me with an upgrade path. Also how would these be mounted? Floor standing or hung on the wall? Do you have any installation pictures?

Thanks,

Bob

bpape · « **Reply #2 on:** 14 Jul 2011, 05:21 pm »

You could slide by with just 1 if using the QRD or Q7D for the 1.7. For the wider 20.1, 2 behind each would be advisable.

They would be wall hung. Don't have any install pics - sorry.

Bryan

rw@cn · « **Reply #3 on:** 12 Aug 2011, 12:41 pm »

I received my QRD,s yesterday and have them temporarily installed, two behind each speaker. Since my room is 12' wide, I had to compromise and put them very close together and very close to the equipment rack and leave enough space for the upcoming installation of the GIK Tri Traps. I'll post pictures a bit later after I compress them.

Some of us pay a lot of money for esoteric tweaks that may only work in our imagination. I've done that. Well, the diffusors work and work very well indeed. My Magnepan 1.7's are enjoying the synergy the QRD's have provided. The sound stage is a bit wider but much more coherent, much of the stridency of poorly mastered CD's is gone, excellent discs benefit from a smoother yet detailed sound (without etchiness). I'll have more to say after I listen more but the improvement in the presentation is noticeable.

Folks, this is a no brainer and a bargain. The installation is easy (if you take your time and measure carefully). The few problems I had were due to the electrician not leveling the dedicated wall sockets (if I had measured them...

) and the fact that my rack is not quite centered in the room.

The QRD's were packed two to a box and packaged securely. Thanks Bryan and all others, for the advice and assistance in getting this done.

bpape · « **Reply #4 on:** 12 Aug 2011, 12:53 pm »

Glad they're working out well for you. Maggies really shine with a little diffusion behind them.

Drop me a note if there's anything else I can assist with.

Bryan

rw@cn · « **Reply #5 on:** 12 Aug 2011, 05:51 pm »

Sorry about the poor photography. Here are three pictures. As you can see I left room in the corners for Tri traps. The wall will look better when they are in place. Unfortunately that means that they are too close to the rack. I am thinking about moving the rack to a different position but it doesn't seem to fit anywhere else in the room.

Ern Dog · « **Reply #6 on:** 12 Aug 2011, 06:46 pm »

I don't see any photos here. Post them again please.

rw@cn · « **Reply #7 on:** 12 Aug 2011, 07:13 pm »

Posted in Gallery. I couldn't get the attachment mechanism to work.

rw@cn · « **Reply #8 on:** 15 Aug 2011, 03:20 pm »

After spending too much time listening this past week-end, I have to say that I am very impressed. My room may not be completely tamed, but these difussors are great. So far there has been no down-side. The positives are that the sound is so much smoother, imaging (which was very good) is now excellent, the mid low-end is no longer a bit thin and the sound stage is a bit wider. I wish that I could move them more to the outside of the 1.7's but I have to wait until I install the corner treatments.

dm · « **Reply #9 on:** 16 Aug 2011, 09:33 pm »

single QRD behind a magnepan 1.6. Works great. These are in the new QRD black color.

rw@cn · « **Reply #10 on:** 17 Aug 2011, 11:13 am »

Thanks. I may back off to one on each side. I'm trying two because I might upgrade to 3.7's which are wider. I'll experiment more once I get the corners treated.

rw@cn · « **Reply #11 on:** 7 Sep 2011, 12:10 pm »

I did try one diffusor on each side and found that it wasn't as effective so I went back to two diffusors on each side.

yo2tup · « **Reply #12 on:** 10 Sep 2011, 04:31 pm »

Quote from: dm on 16 Aug 2011, 09:33 pm

single QRD behind a magnepan 1.6. Works great. These are in the new QRD black color.

did you remove the wooden frame on the QRD's or did you order it that way?

dm · « **Reply #13 on:** 2 Oct 2011, 04:38 pm »

Quote

did you remove the wooden frame on the QRD's or did you order it that way?

I ordered the QRD's "naked" no frames. They were cheaper that way and I built my own wall hanging/support that fit in with the dimensions of my wall screen frame. GIK did paint them black for me, but ordering them unpainted was also an option I considered.

rockadanny · « **Reply #14 on:** 2 Oct 2011, 04:52 pm »

What would be minimum recommended distance behind a pair of conventional rear-ported box speakers?

apog · « **Reply #15 on:** 10 Oct 2011, 07:12 pm »

Last Friday, received and placed 1 QRD each at the reflection point on front wall behind Apogee Slant 8s (ported hybrid with dynamic woofer and 40" ribbon).

WOW! pretty much sums up my reaction. I've been happy with my system's ability in reproducing rhythmic aspects of music and the immediacy of a singer in the room. Adding the QRDs not only leaves those qualities intact (even slightly improving vocal intelligibility), but they make everything else sound materially better. Sound stage has widened a bit on each side and sense of depth is increased. The instruments in between have been brought up in the mix a bit, sound more realistic and are better spread across the stage. There is an improvement in low level detail (processing on voices, background vocals, decay in instruments). In general, I think the QRDs have helped turn my small room into maybe a medium (or at least a 'big' small) sized room.

I've avoided diffusion mostly because there is a double door on the front wall. So, I have to move the left QRD in order to exit the room. Inconvenient, but I've gotten over it. I could add 2 more QRDs, but would want to hollow one out slightly to fit over the door knobs.

In my case the QRDs have made a remarkable improvement, especially considering the cost of less than $300.

Notes:
The room is 13.5' x 15' x 9' and is pretty well treated with Real Traps of various sorts.

Rest of system is Wadia 22 transport, Sonic Frontiers SFD-2 MK I (Parts Connexion SE+) DAC, ARC LS 27 pre & Bryston 14B SST2 Pro. Cables are AT&T optical, MIT Magnum MA, 18' MIT Magnum MA (med impedance) & MIT MH-750 biwire.

Listen mostly to indie pop / rock / folk (lately this would be stuff like The National, Meiko, Young Galaxy, Death Cab For Cutie, Sarah Jaffe, Marnie Stern, Sea Pony, Radio Dept, etc).

Cheerwino · « **Reply #16 on:** 25 Oct 2011, 05:10 pm »

Quote from: dm on 2 Oct 2011, 04:38 pm

I ordered the QRD's "naked" no frames. They were cheaper that way and I built my own wall hanging/support that fit in with the dimensions of my wall screen frame. GIK did paint them black for me, but ordering them unpainted was also an option I considered.

Wait, we can get the QRDs nekkid?

Well that would work much better for me, I think. Glenn or Bryan, how much are the QRDs frameless?

So,what are the QRD "guts" made from? Do they flex? I was thinking of putting something in a window, so I'd like to be able to move it in and out.

bpape · « **Reply #17 on:** 25 Oct 2011, 05:28 pm »

It's not something we normally do but we have done it for customers before. I'd have to get a price. Probably better to email me directly or PM me.

They're EPS material and would be fine going in and out of a window.

Bryan

dm · « **Reply #18 on:** 27 Oct 2011, 07:36 pm »

Quote from: Cheerwino on 25 Oct 2011, 05:10 pm

Wait, we can get the QRDs nekkid? Well that would work much better for me, I think. Glenn or Bryan, how much are the QRDs frameless?

So,what are the QRD "guts" made from? Do they flex? I was thinking of putting something in a window, so I'd like to be able to move it in and out.

Keep in mind that the EPS material that the "guts" are made of is somewhat delicate. Normally the frames protect the edges a bit. Naked QRD's can easily get dinged if you are not carefully when you are moving them in and out of your window. Is this something you will be doing often?

Socrates7 · « **Reply #19 on:** 27 Oct 2011, 09:00 pm »

Is it possible to get GIK diffusors 6' tall instead of just 4'?