MSR Acoustics: Dimension4 SpringTrap

The SpringTrap is described by its manufacturer as a "spring-loaded, triple cavity, ported Pistonic/Helmholtz bass absorber." It measures 46" high, with an 18" x 18" triangular footprint, and fits perfectly into room corners. The concept behind this bass trap is rather unique, in that there's a gasket-mounted wood-panel diaphragm with custom-made precision springs behind the diaphragm to tension the panel so it reacts to and absorbs the appropriate frequencies. Inside are three differently-sized ports that tune the trap to a range of frequencies so that it's effective from 30 to 100 Hz. I installed four SpringTraps into Jackpot! Recording Studio's new control room (about 6000 cubic ft with a 15.5" x 33" floor). Traps were mounted in the corners, except for where the door enters the live room-this trap was placed closer to the room's centerline. SpringTraps look very clean, with a cloth covering on the front giving them a speaker-like appearance. I'm sure our engineers will now be questioned about why we have "all those speakers" around the room-the same question asked about our RealTraps (Tape Op #38). Reviewing sound treatment products is difficult. Instead of pretending that I spent hours with pink noise blaring and my TerraSonde ATB-1 (Tape Op #21) analyzing, or that I installed and removed the product over and over to listen for differences, I'm gonna tell you this. Two months before installing the SpringTraps, I had mixed and tracked for two weeks at Jackpot!. After installing the traps, I mixed and tracked for another two weeks. Listening back to both sets of mixes, it appears that with the traps in the room, I was leaning a little heavy on the low end. Obviously the traps were working in the room, as there must have been less low end at the mix position than there was previously. But despite the fact that these mixes are a little bass heavy (but not to the point that mastering won't fix them), the low end all sits more evenly than previous mixes I'd done in Jackpot!. This seems to indicate to me that the SpringTraps actually did help tame some of the wilder low-end frequencies, and evened out (while reducing) the perception of low end in the control room. Previously, I had calibrated our subwoofer (Mackie HRS120) via the ATB-1 and listening tests to achieve as flat a low end as I could. It appears now I need to do that again and find new settings! But I'm excited because in the end, I think the SpringTraps are able to do what they claim, they were simple to install, they look good, and the control room now has much better controlled low end-something I'd been fighting for from the beginning. MSR's Anthony Grimani did note, upon reading my review: "We haven't always found it possible to measure all the benefits of bass traps with steady-state real-time analysis. You do see some flattening of the response, but the real benefits are visible on a time-based analysis where you can see a shortening of the resonance time. You would need to use TEF, MLSSA, or other time-based analyzer to see the full benefits over the typical 2 seconds of resonance decay-time of a standing wave in a room." Okay, he's right, but my room still sounds better!