You’ve got the right monitors, microphones and plugins and your mix sounds great in your room, but….now it’s time for the car playback test!  Your heart sinks as it now sounds very different with all sorts of wayward frequencies swallowing up the clarity of the mix. You go back to the control room and listen to it again and it sounds fine. What’s going on?

Well it could be that you need to treat your room with sound diffusion?

What is sound diffusion? Effectively all it is (in regard to studios) is a surface point that breaks up the sound wave coming at it.

To get a picture of it in our minds, imagine bouncing a ball off a nice shiny flat wall and because it’s an equal flat surface the ball bounces back to us. That is just like a sound wave approaching a flat reflective surface and bouncing back but the big problem with that is the wave bounces right back on it’s self and cancels it’s self out, this is called “Phase Cancellation”.

Now if we are trying to mix music in a room that has flat walls all around the monitors we will have Phase Cancellation going on all over the place and as result we will be adding and subtracting the mix-down to compensate, but when we play the final mix in any other room or in the car it will sound out of balance (normally it’s the bass frequencies that are the worst offenders).

Ok that’s the problem and the answer is… sound diffusion.

What we need to do is place something on our reflective wall that can break up the sound wave and absorb frequency overtones and this is where the cool looking egg shell or saw tooth studio foam comes in to help. When stuck to a wall in all the right places it stops frequencies bouncing around and messing with your ears during the mix down.

Auralex are probably the most widely recognised manufacture of quality foam solutions. They have specifically designed pieces and shapes to fix all the problems caused by sound wave reflections and they offer a free room analysis of your situation.