Need advice about diffusors

[miserlou]

Hey guys, I'm looking for some diffusors for my small room, maybe some 2x2 panels. My budget is really tight, I wondered if anyone can recommend a manufacturer that won't break the bank.

thanks!!

[Space]

Diffusion doesn't translate well in smaller rooms (approx. 12 feet or less of wall run). What this kind of environment produces (small rooms) is LF build up in the 90 degree areas of the room. Usually the best idea is absorption with broadband in the front corners and at the front wall center, back wall center and often overhead of the listening position.

What size is your room?

[gullfo]

just a quick add - using polycylindrical panels (polys) or 2D primitive root based diffusers are typically better in close quarters than QRD or other 1D numeric types. the key will be the expected use in a control room or live room as they are different in what you want to achieve, so make sure to include the room requirements as well.

[Ethan Winer]

using polycylindrical panels (polys) or 2D primitive root based diffusers are typically better in close quarters than QRD or other 1D numeric types.

I hate to argue with you Glenn, but my experience with polys is exactly the opposite. I find they sound hollow (comb filtering) close up, even though they work fine in larger rooms to avoid flutter echo. I'll take a 1D or 2D QRD over a poly every time in a small room.

--Ethan

[miserlou]

Thanks Glenn and Ethan for the comments. My room is 13.5' x 10.5' with and 8' ceiling. It has been treated by a previous owner for absorption...possibly too much. Except for a 2'x4' slanted glass window on one wall, all walls have been treated with 703 insulation sheets from floor to ceiling and covered in fabric. Unfortunately it's not Guildford of Maine fabric but some tighter weave and I'm sure that the fabric is that transparent, so the walls are probably reflecting some top end. The room is carpeted and the ceiling tiles are 2'x2' standard "run of the mill" drop ceiling tiles, not really acoustic tiles.

The room is pretty dead sounding, but has a slight "ping" to it when you clap. I was thinking of a few foam based corner bass traps to absorb some low end and maybe a couple of diffusers on the back listener wall. Again, any suggestions would be appreciated.

[miserlou]

Let me add that the room lacks "air" if that makes sense. It's doesn't really sound that bad to my ears, but I want to open up the listening environment if possible. That's probably not really feasible given the size of the room, but would well placed QRD type diffusers let the room breath a little more?

[Space]

Assuming this is a control room, then it has much to much absorption. If the carpet could be removed, then I would remove it. If it cannot be removed, then you have to get creative with hard surface material to cover the carpet, e.g. sanded one side only plywood painted or stained to match the existing decor.

Rather than remove the wall treatments you have to look into the same type of process here as well. Something along the lines of John Sayers inside out wall with 1 by material fastened to the existing walls.

What you are doing is adding back the hard reflective surfaces that have been removed/covered due to the complete coverage with the 703, the carpet on the floor and the ceiling tiles.


The ceiling could be modified in the same manner using hard-board or 1/4 inch luan. Again you are attempting to add back the reflective surfaces that have been removed.

Brien Holcombe
____________________________________________
Sound: You can't stop it, you can only try to contain it.

[gullfo]

I hate to argue with you Glenn, but my experience with polys is exactly the opposite.

no worries - by close i mean at least a few feet and like any hard surface in close proximity it can skew due to reflections even if the intent is to diffuse.

[miserlou]

Thanks again for the great comments. I'm a composer, and this is my new studio/control/listening room. There's also a connecting 9'x9'x8' room for recording vocal/solo instruments that's been treated with 703 floor to ceiling that I'm fine with for now.

I'm currently under some heavy schedules, working in a temp room and trying to move into this new room as quickly as possible. But I want to get it as "right" as possible before I make the move. As you can tell, my frustration with the room is multiplying daily The previous occupant had treated the room without consulting anyone, now leaving me with the challenge of making the best of a bad situation. A very common story in these forums, I'm sure

I set up a simple monitoring system in the room (two Mackie HR 824's and an ipod) and was placing the monitors in various places to find a sweet spot. I couldn't find one:( The imaging in the room is pretty bad. I think I also need some bass trapping, there's quite a bit of bass buildup in the corners.

If I remove the entire carpet to expose the cement floor, would that not couple with the ceiling and introduce flutter echo of some kind? Could I instead liven the room up by put up some type of flat panels or diffusers at target points?

[miserlou]

Sorry about the double post, I'm not sure how to delete it. Space, feel free to delete the double post

Here are some pics of my room, pretty messy but I'm sure you guys have seen it all:

http://rednoteaudiocom.siteprotect.net/NewRoomPics.zip

The room is 13'7" by 10'6". The long way is from the exposed brick wall (front wall) to the back wall with the long window. The top ceiling grid is 9' and the lower ceiling grid is at 8'. The speaker placement you see now is not permanent, just experimental for now.