Hi Jon, and Welcome to the forum!
The room is rectangular and the measurements are L= 3,45 meters, W= 2,80 meters & H= 2,40 meters.
Ouch! That's pretty small! The recommended minimum size for a critical listening room, is 20m2. It is possible to have a good room in less space, but the smaller the room is, the more treatment it needs...
And there is a sofa a bit behind the mixing-chair. We hope it will work as a bass-trap.
It might help a bit, but it's made of the wrong materials an is in the wrong place to be a good bass trap.
What material should we use and where should we put it?
Before you think about materials and treatment, you first need to get the geometry and setup correct.
First, the speakers: They need to be set up so that the rear corner is 10cm from the front wall, and the acoustic axis is 79 cm from the side walls (so they will be 122 cm apart from each other). They also need to be set up at a height of 125 cm above the floor. For all of those measurements, I'm talking about the location of the acoustic axis of the speakers, not the top, bottom, or side of the speaker box. You'll need better speaker stand, too. Those are very flimsy. Speaker stands need to be massively heavy.
Next, the mix position: Set up the chair on the room center-line, such that your ears will both be about 130 cm from the front wall when you are mixing normally. Now set up something vertically (such as a mic stand), about 30 cm behind your head, also on the room center-line. Carefully rotate each of the speakers so they are both pointing perfectly at that vertical pole.
That's the correct geometry for your room. Set up the desk in front of the chair, so that it is in a comfortable position.
Now the treatment: Take down that shelf on the left wall, and remove the speaker in the right front corner. Those are both creating a symmetry problem, and they are both in locations where you will need treatment.
Now buy some sheets of "Owens Corning OC-703" insulation, 10cm thick. Cut some of it into triangles that measure 50cm along the two shorter sides, and stack those up in the front corners of the room, from floor to ceiling. Yes, the one on the left will partly cover the window, but you have no choice. Make a simple frame to cover that, and put some very thin plastic film on the inside of the frame (facing the insulation), and decorative fabric on the outside (facing the room). The plastic should be about the same thickness as a newspaper, roughly.
Do the same for the left rear corner of the room, where you have the mic setup at present. You should really have another one in the other rear corner, but the door is in the way...
OK, those are your "superchunk" style bass traps. They aren't big enough, but it is impossible to make them bigger in that room: they would take up too much space.
Now make set up two small panels of OC-703 behind the speakers, up against the front wall, about 80cm wide and 100 cm high. (Yes, they will cover the windows too: but once again, you have no choice). Center those between the speakers and the wall.
Next, make two wooden frames, each one 15cm deep, 1m wide and 2m high, and put a piece of OC-703 inside each frame. Cover the frames with decorative fabric, and hang the frames on the side walls, at the first reflection points.
Finally, cover the rest of the rear wall completely with more OC-703, two layers deep (20cm): You can put it in frames if you want, and cover it with fabric to hide it.
That's about all you can do with that room. It won't be fantastic, but it will be a LOT better than it is now!
- Stuart -
