RealTraps room treatments
It wasn't a large room (15' L by 9' W by 7' H), and, looking at it empty, I realized that by the time I'd installed a queen bed in there, there wouldn't be tons of space left for any other functionand besides, how often did guests sleep over? So I did what any audiophile would do: I decided to turn it into a dedicated if economy-size listening room.
It was a basement room: two walls were foundation block, covered by lath and Sheetrock, with the remaining two walls and ceiling comprising Sheetrock over genyouwine antique 2x4s. The floor was ceramic tile over concrete. This "spare" room was the only room in the house that wasn't jammed full of bookcases; minimally furnished, it sounded hideousclattery and shrill, with lumpy, ill-defined bass.
I added a thin llama-wool rug and a thick carpet pad of crushed foam, which helped reduce clatter a tadpartial treatment of the first floor reflection, perhaps? The shoutiness and lumpiness persisted, so I hung additional rugs on the rear and sidewalls. This had little effect on the room's most serious frequency aberrations, but it did reduce HF clang, if not necessarily in a good way.
Sometimes you Trap yourself
Since I'd already worked out a way of hanging rugs without putting holes in them, I reasoned that I could roll my own room treatments by building frames of 1" by 4" furring strips and hardware cloth, then loosely stuffing them with Mountain Mist Polyester Fiberfill, manufactured by Stearns Technical and left over from an aborted loudspeaker project. (I knew it would come in handy one day.) I then hid the completed panels behind the wall hangings and sat down to listen to some music and bask in my genius.
Even behind the hangings, my panels were butt-ugly. Worse, the room sounded really badmaybe not as bad as when completely untreated (though even this is arguable), but still clattery, now extremely bass-heavy, and somewhat muffled in the highs. There was no air, no imaging, and damned little pleasure in listening to music there.
My first thought was to relegate the room to burn-in duties, pre-cooking electronics and running-in speakers using the tried-and-true method of wiring 'em out of phase and facing 'em toward each another. But I couldn't let go of the idea of turning the room into a reviewing tool. I read some more about DIY room treatments and decided that I just didn't have the space or the tools to make serious bass traps, or even-frequency absorption panels. So I did what audiophiles so often do: I looked for someone else to solve my problem.
That person turned out to be Ethan Winer, co-founder and co-owner, with Doug Ferrara, of RealTraps, LLC. I sent Winer measurements and photographs of my room, and he came up with a multi-part room-treatment plan. Part 1 was to tame the LF lumpiness caused by my room boundaries, for which he recommended hanging four RealTraps MondoTraps (57" H by 24" W by 4.25" D, reviewed by Jim Austin in August 2007) across the room's corners, leaving open space behind them. The MondoTrap ($299.99) marries a loose membrane to a rigid fiberglass core that dissipates "trapped" sound as heat and, according to Winer, works best when sound can "enter" it from front and rear. Technically, a MondoTrap doesn't have to go in a corner, but anywhere else they took up more space than I was willing to give them. Besides, when I mounted low-wattage CFL bulbs behind them, I had me some mood lighting for listening sessions.
Sometimes you get Trapped
Adding the four MondoTraps completely transformed my small room's bass responsesuddenly, I could hear the wonderfully fat bass licks in "Crystal Blue Persuasion," from The Best of Tommy James and the Shondells (CD, Bellaphon 28607004), which had previously gone missing in action. The punchy bass line in "Third Uncle," from Doug Hilsinger and Caroleen Beaty's Brian Eno's Taking Tiger Mountain by Strategy (CD, DBK Works 111), became, well, punchy, and began to coalesce between the speakersat least, more than it had before.
Winer then suggested that I add two MiniTrapsessentially, small MondoTraps measuring 48" W by 24" H by 3.25" Done on the front wall, between the speakers, and one in the middle of my rear wall, about 3' behind my listening chair. The MiniTrap ($199.99) offers bass absorption down to about 80Hz, and perhaps even lower if you "float" them on spacers to leave air space behind them. The MiniTraps' immediate effect in my room was to even out the mid-to-low-HF response; I now had no room clatter, and instruments had bodies and, yes, even air. Better, my speakers now threw a coherent, near-holographic image right smack dab in the center between the speakers. On "Third Uncle," the bass line bounced from speaker to speaker and seemed to whirl around the room, while Hilsinger's primal drumming had presence and physical heft. Massed voices, such as those of the Estonian Chamber Choir in Arvo Pärt's Kanon Pokajanen (CD, ECM New Series 1654/55), possessed a solidity and that wonderful weighty-but-weightless quality that voices can have in a good acoustic. Before I added the MondoTraps and MiniTraps, my listening room had masked that quality.