I'm also interested in what you learn about what works and doesn't with the room treatments. I'm overdue to treat my practice room...
My room treatments are designed for particular mixing and recording issues.
The black ASC Tube Traps you see in the picture are pure bass traps, and they work pretty well. To keep them from absorbing too much high end and making the room or something in front of them too dull, on one side they have high frequency diffusers built in. But I don't really have enough of them left for truly effective use; you need at least 8-10 of them, and I'm down to four. I had more that over the years were damaged, and I got rid of the damaged ones. However at $500+ apiece, coupled with the fact that a 4 foot by one foot cylinder in the middle of the room isn't very attractive, I've decided to go in a different direction.
Tube Traps don't cover a lot of room surface, so I'm moving to RealTraps for both HF absorption and bass trapping. RealTraps are every bit as well made as the Tube Traps, but hang on the wall instead of taking up floor space on a stand.
Both the RealTraps and the Tube Traps are significantly more effective than foam absorbers. The foam stuff is OK if you're short of cash, but not only is its performance limited to higher frequencies, I found that even the good Auralex stuff tends to disintegrate after a while, and it needs to be glued to the walls with adhesive that is very difficult to remove if you need to move things around or replace a panel. I had Auralex in my old studio's vocal booth. Never again.
In a small room like mine (about 14.5 x 30) bass trapping becomes essential in the corners of the room. I've got some RealTraps Mini Traps coming to handle that, there will be two in each corner of the room, and the Tube Traps will only be used for spot duty in front of guitar cabs. Having two in each corner not only maximizes the amount of bass trapping that will go on, it'll also help tame room reflections.
Second in importance to bass trapping is absorption of excess reflection, and I've been testing RealTraps Micro Traps, 4 feet x2 feet at the first reflection point of my monitors, and am really happy with them, so now I'm a believer. I don't want the room too dead, so these are at first reflection points in the workstation area, and more will be spaced a few feet apart in the recording area when they arrive.
In this shot of the workstation area, you can see two of my Tube Traps in the corners for bass absorption, and two of the RealTraps Microtraps along the side walls for first reflection point absorption. There's actually a mathematical formula for placing the reflection absorbers once you've measured all the variables.
Eventually, I'll also install true diffusors on the rear wall of the studio, but again, the expense is considerable. And diffusion is sort of "icing on the cake" since my listening area is 20 feet from the rear wall; the sound is fairly well scattered by the time it arrives at the rear of my head.
I don't need to be concerned with soundproofing, it's impossible without some significant construction and specialized materials, and unnecessary for my current situation.
Everything also depends on how your room sounds. For whatever reason, my room is basically good sounding, even without acoustic treatment. That is, vocals sound real, not boxy, acoustic instruments record well, and electric guitars and basses record well once their ability to rattle the room is tamed with structure isolation.
So what I'm after is maybe just a bit drier sound, not too much absorption, just enough to tame the very little bit of flutter echo I get without killing the good qualities of the way the room sounds.
Kidding aside, I know what you mean...
