Looking for reasonably priced sound diffusion.

I am looking for sound diffusion panels for placement on my ceiling. They need to be lightweight (no holes in the ceiling) effective and reasonably priced. No more then $80 panel or so for 2X2 feet. Like to actually spend less.

I have seen products by RPG - Skyline and Auralex - T-Fusers. The Skyline is to pricey. Not sure about those plastic looking T-Fusers.

I have good absorption and simply want to mix in a few diffusers on my ceiling and perhaps behind my speakers replacing absorption panels now there. The side walls and wall behind me have good absorption. I also have floor to ceiling bass traps behind the speakers in the corners of the room.

My sound is very good, but I feel this could be a nice final room touch. Perhaps helping out things when music is played very loudly which I like to do at times.

The room is 24 feet by 18 feet with 8 foot ceilings. You can see my room as part of my virtual system.

My speakers are out 7 feet from the front wall.

Thanks for your help.

I’ve a couple Q’s here myself, please. … and maybe an answer as well for the OP…. or at least an alternative choice

First… How low a ceiling does one have to have for these things to be of consequence? Or is there some specified distance from the top of the speaker to the ceiling in order for these gizmos to be effective?

Next… Why would actual diffuser panels or squares be better and how does one decide how much and where to place it/them?

When I repainted and remodeled the living room for a theater, I wrongly listened to others and had the ceiling painted a similar but softer white. Bad move. The eye catches enough of it to be distracting as the screen is wall mounted, so it needs to be much darker.

I vaguely recall a wall paper maker that has a fairly good selection of fabrics and colors that act as diffusion and very slight absorption. Materials and are assigned the terms ‘Acoustical room treatment fabrics’.

The idea of diffusion on the ceiling and changing the color as well seem a good enough reason to put the difuse wall paper up there in my circumstance. As it won’t catch the eye like individual panels will, and should prove quite complimentary without over damping a room.

It can be had in tiles or rolls depending on who you get what from. In one case I noted 12 tiles sell for $35.




other’s are out there for sure… just keep Googling.
Wow, some great stuff here. Thanks to all for taking the time to post. I am most interested in those acoustic tiles on the website


Blindjim, do you use these? Has anyone tried these? Goodness they are easy to put up, attractive and cheap!!! These may be one heck of a find. Just wonder if they are effective. This could be an answer to diffusion for all of us Aphiles on a budget. They look great also!

Blindjim asks some very good questions and I don't have the answers to be frank. Hope others can share from experience .
ASC cool traps are new and what I used. I can't remember the price but that come in quanities of 16 and are 1 foot square. It seems to me they were like $300 or so for 16 but I could be terribly wrong. They look good though when placed together in rows and do the trick for sure. They can be used in a variety of ways, not just ceiling. I have some left over and have yet to figure out where to go with them.
I've done quite a lot of diffusion studying, communicating with Prof Trevor Cox and Dr Sean Olive, and built several DIY Skylines and Hemi-Cylindrical diffusers, so I hope my words of wisdom will be considered by you.

CAUTION: www.mioculture.com/store/pc/vi... This stuff is recycled paper, is only 2.25" deep, and its installation instructions say it will warp with humidity. RED FLAG, RED FLAG, RED FLAG. Paper is too thin to be considered a diffuser, except for the highest of frequencies (which is great if you're a bat). It's depth needs to be a miminum of 8" so 2.25" is clearly inadequate. So, I'd recommend you pass on it. (I guess you get what you pay for in this instance.)

Why do you want diffusion (or anything) on the ceiling? Is it to raise the apparent ceiling height? I can tell you from 1st hand experience that the RPG Skylines on my 7ft ceiling had little effect on raising the apparent stage height. Dissapointed - yes, a bit, but it could be due to any number of things like my speaker's vertical off-axis response being poor, too sharp an angle to 1st reflection point based on sitting distance from speakers etc etc.

Have you considered using say 2"*6" or larger planks of wood and angling them? Start with the 2" part touching your ceiling and hanging down perpendicular to the ceiling and running across the room width of your ceiling to cover the left and right 1st reflection points. Then begin to move the bottom of the wood up and towards your speakers; any sound hitting the ceiling will become trapped inside the area bound by the ceiling and plank and will bounce around before coming out delayed and attenuated. Hang several of these and you can elect to put some fabric over them and put fibreglass inside the fabric to partially absorb some of the sound.

Another effective and yet reasonably priced product is GIK's D1 diffuser which follows a modified QRD pattern. Hang them so the well orientation aligns with the room's length so sound hitting it will be diffused to the sides.

You will want diffusion that latterally affects the sound so QRD (with wells oriented vertically) or hemi-diffusers (convex and length oriented vertically) should do the trick. Latteral sounds help envelop the listener and widen the sound source, both positive traits.

With any diffusion product, it is the depth of the QRD wells, Skyline cells, or hemi-cylindrical radius that determines the low frequency that it will effectively work to. You want one that will work down to 300Hz (which is a good estimate for a residential room's Schroeder/transition frequency) for which Dr Floyd Toole recommends a minimum of an 8" depth for QRD and Skyines and 12" depth for hemi-diffusers. The material needs to be firm enough - no paper products please - to be effective at diffusing high and medium frequencies.

PLACEMENT: I would suggest that you put diffusion on the wall behind your listening chair before you try the front wall. Firstly, you're sitting closer to the back wall so it's effects should be more pronounced and will help deal with many 1st reflection paths from the speakers. Secondly, unless your speakers have rear-firing tweeters that're turned on, the front wall is likely the least important because sound has hit several surfaces before making its way to the front and each surface 'hit' attenuates it, and the sound signal experiences propogation loss (6dB down per doubling of distance). My experience with absorption on the front wall - I'm excluding bass traps in the corners now - is that the absorption will deepen the sound stage while diffusion will bring it forward, clearly a personal preference thing.

I would suggest that you also take down the side wall absorption - especially if it's thinner than 4" - and listen with just the bare wall as Toole's studies have shown the side wall reflections to be GOOD things in widening the apparent sound source when enjoying music. He saying that side wall 1st reflection points should be absorbed when you're mixing music or evaluating listening components.

In my room I had a wicked slap echo between the side walls so my hemi-diffuser (i)killed the spap echos, (ii)had a hard exterior (i.e.red oak veneer) so that medium/high frequencies weren't absorbed and (iii) used OC 701 fibreglass inside it for addional bass trapping. I experimented with moving the hemi-diffuser along the side wall and found the best sound came when the 1st reflection point on a side wall from the closest speaker was left bare (i.e. reflective) while the reflection point from the speaker across the room was diffused. This seems to align with Toole's research that says the most significant side wall reflection comes from 60degrees (looking straight ahead = 0degrees and over your shoulder would be 90degrees). You can use trigonometry to figure out where the 60degree point is and mark it - it may be very close to the 1st reflection point of the closest speaker when you use the mirror tecnique.

Thanks so much for all of the information.

Very nice of you and you seem quite knowledgeable.