Room acoustics (especially bass traps)

I am lucky enough to have a dedicated room, albeit small, in my house for a studio setup.  Problem is that I am convinced that my sweet spot is sitting in some kind of bass node.   There is also no furniture in the room and I am sure there are problems with the reflections from the walls.

I’ve been lurking at the studio acoustics forum at and understand that the first treatments you should be looking at are bass traps, made of dense material (rigid fiberglass/rockwool).

Big question is has anyone on the forums made their own bass traps, where did you get the material or did you just buy some?  I’m based in Northern Ireland and don’t really want to pay the shipping costs from the mainland to have premade bass-traps shipped over if I can buy materials here and make my own.

Rockwool is often used in gardening, so I would check out any local shops and seek out suppliers that are near by.

Even if you are unable to find some, it would be far cheaper to order the rockwool instead of the ready made bass-traps.

you can get rockwool from any builders merchant or focus,b&q etc and its cheap enough :wink:

I thought I’d post a bit of a DIY tutorial on how I made my own acoustic panels (bass traps and reflection absorbers) just incase any of you were putting off treating your space because you thought it too hard or had no idea where to start.

The best way to start is just to do it!! Once you’re on a roll, you won’t be able to stop yourself - and your ears and your mixes will thank you.

You can do it very cheap, the whole treatment costing ~$400AUD [~$280 for the rockwool, ~$40 for the wood, ~$80 for the hardware to put it all together]. This made me around 6 - 1500mm x 600mm bass traps and 10 - 700mm x 800mm reflection absorbers… which is about perfect for my smallish room.

Note that I’m talking about absorbers here. There are a couple of other ways to help your room acoustics, but are more complicated than this.


Room acoustics in general is a VERY complicated matter and can get very mathmatical, which I guess is why a lot of people put off acoustic treatment in their studio space.

In no way is this acoustic treatment going to cure your room of all it’s acoustic problems, however, it’s one of the best effectiveness vs. cost ratio - and it should definately help to clear up those muddy mixes.


I’m not going to pretend to be an expert on this, but I thought I’d at least explain the basics:

In a standard untreated room you’ll probably have a couple of issues that will affect the clarity you should be recieve from your expensive monitors. These are:

* Mid-high (mostly high) reflections. This is sound reflecting off your walls that can cause things like phasing, which is basically where certain frequencies will seem louder or softer than they actually are in your mix due to them bouncing around your room adding together at the point around your ears, causing you to unnessessarily boost or cut those freqs - bad!

* Also, commonly in small rooms are standing waves [or modes] at the low end of the freq spectrum (generally <-100hz ). This is directly affected by your rooms proportions, relating to frequencies having a particular length per cycle. A number of specfic frequencies will reflect back and fowards (and up and down) around the room and add themselves in-phase with eachother. They of course dissipate quickly, however, those frequencies will be of greater amplitude than desired and also linger in the acoustic space longer than other frequencies - bad again! for instance… a major mode in my room is 43hz. 43hz takes 8 metres too finish it’s cycle - and it just so happens that my room is exactly 4 metres long… coincidence, not at all

These are very basic issues most people have with their home studio setup - if you’re interested in acoustics, do some more research. For more info, a great forum on acoustic treatment is . There’s lots of pro dudes on there that have some great advice for people like you.

Acoustic material

One of the best insulators for sound treatment is rockwool. It absorbs sound fantatsically and it’s easy to work with (and no where near as painful or dangerous as fiberglass).

In it’s denser form it’s quite firm, and stands upstraight (as in the pictures)… however, being so ridged, you don’t want to handle it too firmly as it will break away or crumble - so be gentle with it and get someone to help you if need be. Also, even though I’m handling it in the picture, it can be irritating to the skin (similar to grass itch). This is a mechanical itch, not a chemical one, so don’t worry too much if you’re itchy after working with it, just have a shower and change clothes.

Wear gloves and loose, longsleeve clothing to avoid ichy issues.


Making the Acoustic Panels (finally)

I made two different traps here… one for the reflections (high freqs) and one for the bass (modes):

You’ll need:

* Rockwool

* Gloves to cut and handle to rockwool

* Wood to make the frames (I used pine)

* ‘L’ Brackets

* Lots of self-tapping wood screws

* Dowel to hold the rockwool in place in the frame (I used about 9mm)

* A Staple Gun

* Material to cover the panels (something that has a bit of resistance when you blow on it)

* And any tools to cut the wood and drill the screw in

I made the reflection panels out of the less dense (less expensive) rockwool [20kg/m3] as higher freqs don’t require the density that the bass freqs need. When building bass traps, use a density over [40kg/m3] for the best effectivness.

I started by building pine wood frames that suit the size of the rockwool batts I bought. I bought wood that was about 20mm deeper than the rockwool I was using so I could drill holes in the frames at the back to stick 9mm dowel through to hold the rockwool at the base of the frame (as shown):

Putting them together with ‘L’ brackets was the easiest way for me to do this:

Lay everything out in a space that you can work easily. For me, the only place was in the backyard (and yes, that’s real grass, nice eh? ):

If need be, cut your rockwool to fit your frame using a box-cutter, but don’t push down when you cut, just gently ride the blade across the rockwool a few times to avoid damaging the edges.

Place the cut finsihing fabric on the ground ready for the panels to sit on top.

Put the frame (with the dowel facing up) on the rockwool so it sits neatly inside the frame (you may have to trim the edges to make it neat).

Move the panel containing the rockwool to sit ontop of the fabric (rockwool facing down, dowel up).

Fold the fabric over the edges of the frame and staple the fabric to the wood.

Once you’ve done that. Staple more fabric on the back just to cover the rockwool on the rear side. You’ll be left with something like this (the front one is turned around to show the black rear side):


Place reflection panels on the walls either side of you, halfway between you and your monitors. This will dissipate what is called ‘first reflections’ which are the most predominant. You can also place then behind you and on your ceiling (again, halfway between you and your monitors). Attatch the reflection panels to the wall however suits you best.

Bass traps, on the other hand, work best if they are not directly touching the wall so they have space to absorb sound bouncing back from the corner walls through their back (hence is why we leave the back open on the panels). They are most effective in the corners of your room (either the wall-wall, wall-ceiling or even wall-floor corners). Either use ‘u’ brackets to attach them to your wall, hang them from your ceiling with cables or brackets, or if you’re crazy enough - drill holes in your wall and run high-tention cables around the room to suspend your traps from (like I did). Letting them hang free will also let them freely resonate for most effectivness:

The end result

Something to be mindful of is not to deaden your room too much with absorbers. In general, it is desired to keep a level of acoustic resonance in the room to keep the room ‘live’. If you deaden your room too much, you’ll find yourself using too much reverb to compensate.

Enjoy and good luck!!

Hopes this helps everyone out!

From  synaecide on idm ?

Correct Sir!

That place is filled with knowledge. Thats what I do all day while working, is reading up on stuff.

I remember reading a bit of this a while back and then forgot which site it was on ,picked up a pdf of something similar ,cool find man!:slight_smile:

Thanks for that Howie!

I would just like to add here that the most important thing if producing dance music is put bass traps in the corners of the room.

If you think of it, its crazy to spend hundreds on monitors with a ‘flat’ response and try to use them in an untreated room which will cause massive peaks and troughs in the sound that reaches your ears.

I’m trying to hunt down the materials to get some traps built and I can’t wait as I know its gonna make things a lot easier when making decisions on the low-end of my mixes.

I was going to say exactly what Howard said only with more exclamation marks

Bouffont (who is in awe of howies reply)

You want bass traps in all 4 corners if possible, GIK acoustics do an awesome ‘tri-trap’, then from your listening position, get someone to walk around your room alongside the walls with a mirror, wherever you can see your monitors in the mirror you should really have some panels, try to stay away from foam



Believe or not but I got my DYI tut from Sonic Academy!! Thanks guys!!

I used fiberglass. I couldnt find rockwool slabs or cornings 703 anywhere at my local hardware shops. (US). Sad to report…fiberglass didnt meet my expectations. Although I still have a ways to go in padding up the room.

Uploaded with

Heres a great vid on placement of your room treatment. Although the video is for Auralex, Ive read foam and their products in particular are exactly equivalent to DYI methods and sometimes better i.e. DYI Cornings 703s bass traps. But placement is very important and this video points out some key locations.

Also check the absorption coefficient, use materials that have high absorption near to your problems frequencies, and the mass law, If material x reduces by y dB then double x to achieve another -6dB reduction (frequency dependent :))