I installed 3 absorption panels in my studio. Two on the ceiling and one on one of the side walls. All panels are from the EQ Acoustics Spectrum product line, rigid absorption panels which can be mounted on a wall or ceiling.
This is the Spectrum 50 Studio Tile. The tile measures 57.5 x 57.5 x 5 cm. Self adhesive hook strips are provided to be able to mount the tile directly to a wall. As my studio has wallpaper on all walls I made a wooden frame first and taped the tile to the frame. Then I was able to mount the frame with the tile to the wall like a regular painting without the risk of the tape ruining my wallpaper and the tile falling off.
EQ Acoustics provides special hooks for mounting panels to a ceiling. They call it Spectrum Studio Ceiling Clouds. The hooks look like little metal springs and you just screw them into the corners on the back of the panel. The Spectrum Studio Tiles are available in several colours. I choose red for the wall tiles and natural for the ceiling tiles.
I already have some panels for the wall behind the monitor speakers but I haven’t installed them yet.
After installing the tiles I did another acoustic measurement to see if things had improved. I did not expect a very large change but there are some things which already improved a bit. Below are the results where the before and after characteristics are presented in one view so you can easily see the difference. The red graph represents the untreated room, the purple graph represents the characteristics after installing the three absorption tiles.
In the low frequencies a bit of improvement can be seen but there still is that nasty dip around 185 Hz. Most of the improvement here however should come from the yet to install bass traps.
The higher frequencies are pretty much the same but there now is a much better representation of frequencies above 10 kHz.
The RT60 characteristic (Reverb Time to decay by 60 dB) shows a nice improvement in the low frequencies and the higher frequencies also improved a bit. They are now around 200ms which is OK. After installing the other panels and the bass traps this should still improve though.