A small room is the hardest place to mix. The walls are close to your ears and the sound has nowhere to go, so you hear your speakers and then, a few milliseconds later, the same sound bouncing back from the desk, the side walls and the ceiling. The result is a mix that sounds fine at home and wrong everywhere else. You don't need a studio budget to fix most of that. You need to place things well, absorb the right spots and know which parts of the sound not to trust.
What a small room does to your sound
Two things go wrong. The first is reflections, which smear the stereo image and blur the mids and highs. The second is bass build-up. Low notes have very long wavelengths, and in a small room they pile up at some frequencies and cancel at others. A kick that sounds huge on one bass note and vanishes on the next is usually the room, not your mix.
Acoustic treatment changes how a room sounds inside. Soundproofing stops sound from leaving or entering. They are different jobs, and egg cartons or thin foam do neither well.
Place the speakers and the desk first
Placement costs nothing and gives the biggest change, so do it before you buy anything.
- Set the speakers and your head in a rough equilateral triangle, with the tweeters at ear height and angled at you.
- In a rectangular room, try working along the short wall, with the speakers firing down the length of the room. Bass is often more even this way than when you face the long wall.
- Pull the speakers away from the wall behind them. Pushed right against it, they make the bass swell. Even 20 or 30 centimetres helps.
- Don't put your head exactly in the middle of the room, and don't sit with your back against the wall. Play a bass-heavy track, move the chair a little forward and back, and stop where the low end sounds most even.
- Put the speakers on stands or isolation pads instead of directly on the desk, so the desk doesn't ring along with the bass.
Absorb the first reflections
The first reflection points are the spots on the side walls, the ceiling and the front wall where sound from the speakers bounces once before it reaches you. They do the most damage, and they are easy to find. Sit in your mixing position and ask a friend to slide a small mirror along the wall. Wherever you can see a speaker in the mirror, that is a reflection point. Mark it with tape and put an absorber there, plus one on the ceiling above your head. This alone makes the stereo image clearer.
Build absorber panels yourself
A simple panel is a wooden frame filled with mineral wool (rock wool) or dense insulation board meant for building use, with fabric over the front. The steps are short:
- Build a wooden frame as deep as you can afford. Ten centimetres is a good aim, because thicker panels absorb lower frequencies.
- Fill it with insulation cut slightly bigger than the frame, so it holds by itself.
- Cover the front with breathable fabric, such as thin cotton or burlap. Never plastic.
- Hang it, or stand it on the floor, at the marked points. A small air gap behind the panel helps it absorb lower.
Wear a mask, gloves and long sleeves when you cut insulation, and cover every side with fabric so fibres don't get into the air. Ask the shop for material that is safe for indoor use.
Bass traps, rugs and curtains
Corners are where bass collects, so thick absorbers in the corners tame the low end more than anything else you can do cheaply. They need real thickness to work, because a thin trap does almost nothing at low frequencies. Start with the two corners behind the speakers.
Cheaper household items help with the higher frequencies:
- A rug between you and the speakers cuts the floor reflection.
- A heavy curtain over a window or a bare wall softens the highs.
- A full bookshelf scatters sound, which works as free diffusion.
Clap once in the middle of the room. A fluttering ring means two bare walls are bouncing sound back and forth, and a panel or curtain on one of them will stop it. Don't go too far: a room with too much absorption sounds dead, and you will end up pushing the highs in your mixes. Add treatment in steps and listen after each one.
Check the low end with headphones
Even a treated small room needs a second opinion on bass. Headphones have no room problems, so they show whether the kick and bass are balanced and the low end is clean. They are a second opinion, not a replacement, because they exaggerate stereo width and don't give you the physical feel of bass.
A reliable routine: play a commercial track you know well in your room and on the headphones, then your own mix in both. If your bass is louder or quieter than the reference in both places, it's a mix problem. If it only changes in the room, it's a room problem, and you know to trust the headphones for that part.
Good placement and a few well-made panels beat expensive gear in a bad spot. Move the speakers, find the reflection points, build a few panels, and listen for a week before spending more.