Extreme basstrapping with corner- and panel-absorbers, PICS!

Hi there, my room is 6,63 m long, 4,54 m wide and 2,25 high, what i know, is not really perfect but I have to handle this. An issue of this room is, that it is in basement and I have to leave some space (around 20-30 cm) in one corner because of moisture so that the air can transport it away from the corner. Unfortunately in the rear corners are the door and an other window, so that I can not treat here anything. Cieling is painted concrete, floor is glazed tiled, walls are paperhanged. Windows, door and radiators can be watched in the pictures. I have built some basstraps with 45kg/m^3 glass wool, each pack around 1 m long and 40x40 cm. You can not see them in the pictures, but they are installed in the corner near the windows. I used them in my old room and they worked fantastic. In addition I have built some angeled walls to break the parallels in the listening zone. Propably I will do so on the rear wall, too. At the ceiling I have put 4" glass wool above the listening zone to avoid reflections. As you can see in the frequency-plots the simple bass treatment with the traps are doing something well, but I still have some heavy resonances. I would be happy if someone can give me some hints about my room. I can not built new walls, because it is rented!! Main Question: The most important thing is to flaten the frequency response and get rid of the nulls and peaks. I plan to build panel-absorbers for this. I have experience with that, but always build them directly on the wall. Now I would like to build them free standing at (!) the wall like a closet. Is 16mm MDF thick enough for the corpus? Best Regards, Studiotools

here are some real pictures of the current state, but without the basstraps the are in the kitchen right now, so I could do the measurement. perhaps I slat the angeled broadband absorbers, but I do not know yet. Has anybody an idea why the software RoomEQ have the Waterfall diagram only until 400 Hz? I'd like to see how the high frequencies do behave, too.

have you tried moving your speaker and sitting positions?

Hi Gullfo, thanks for the answer. I first located the 38% rule but this was no good position. The measurement with basstraps is the best result I can get, when moving around. I even tried the 90° position of the speakers, what makes an interesting and wide stereo-image. What you can see on the pictures is not really the current position. Did you ever built panel-absorbers that are not fitted on the wall? Cheers, ST