Got some advice earlier on a room and I am very grateful for that!
But now we have done some changes to it and we need some more advice.
Put the same content on the same thread, as I used for the first advice, in the commentfield but I didn't get any answer.
So decided to make a new one. Hope I am not crossing any rules

Here is the measurements: L= 3,45 meters, W= 2,80 meters & H= 2,40 meters.
the walls and roof are of wooden panels. The floor is a wall-to-wall carpet.
On one of the short-walls there are four window-frames. Two pair of same sized window frames. One pair is quite small (maybe 20x80 cm) and the other pair is much larger. About 80x80 cm. Don't have the measurement of how deep they are (sorry) Probably about 20-30 cm. On the opposite wall is the door, also wood and it flushes with the door.
I'll post some pictures as well so you'll see how it looks like.
The room will be used for pre-prods, simple mixing, recording of synths, vocals and other simple recordings that can be done in this room.
The budget is as small as possible. But we have a roof at about 1200 dollars. +/- .. ..
So grouping my questions:
How can we make the room sound as good as possible with the information I have given you?
What material should we use and where should we put it?
Other useful things that I probably haven't mentioned?
Grtz,
Jon
Aspiring studio-dude.