JMLAB MINI UTOPIA and ROOM PROBLEMS

Hi Dlyk, how high is yr ceiling in the 1st room? It looks like you have yr system in a resonant (open) shoe-box... My guess is U should start by tackling 1st reflection points, floor & side walls. Then tackle the back wall. Use rugs, old blankets... and check out differences one by one. You may want to reconsider speaker placement -- check out a relevant thread by Redkiwi on this site.
Good luck!

I'm going to guess you have 8 foot ceilings (2.5 M), which would be good. If you have 3.3 meter ceilings that can create a problem for you as it is the same as one of your other dimensions. Greg suggestions are correct--get a rug--a remnant area rug to cover at least 50% of the area on the floor. You will also need to get rid of the first reflection on the side wall and probably the rear wall. One cheap way to do this is to buy one of those egg crate mattress pads. Cut it into 1 meter squares (or whatever size that seems reasonable to combat the 1st reflection). Also put a larger (maybe 1 x 2 meters) behind the listener on the back wall. If you want to make it look decent just build a wooden frame and cover it with cloth. This works pretty well for high frequency problems--which by your comments sounds like the majority of the problem. For low frequency it's not so easy, but you can build some effective bass traps to go near the corners behind the speakers. For this, a frame that will hold newspaper where the edges of the paper is exposed. The size effects the amount of absorbing--about 1 meter high is what I have used. Fill the frame with folded newspaper put a top on it (just for looks) then cover it in cloth. This is a pretty effective bass trap--not as good as RPG or other commercially available products--but you'ld be surprised how well this works for 100 Hz on up.