Recording - June 2011 - 17

for aesthetic purposes. See Fig. 6.) 4. Build the two floating walls, one at a time, on the floor, then lift them up into their places. This is necessary so that both sides of the new walls can be worked on. The new walls have five layers: two layers of plasterboard (again with nonaligning seams) on the outside, supporting metal bars with mineral wool between them in the middle; then another two layers of plasterboard on the inside. This structure will supposedly reduce sound by about 65 dB. Figures 7 through 11 show the layers. The walls are not actually fixed into anything. There are narrow, padded support bars at the top and the bottom on the outer side, fixed into the ceiling and the floor, that will prevent the walls from falling outwards, but the walls themselves do not touch the ceiling. They (hopefully!) stay where they are by gravity and polyurethane. Because of this there is less leakage from the monitor speakers through the floor (which also does not touch the old walls) to the new walls and from there to the ceiling and out of the room. Figure 12 shows the ceiling supports. 5. Fix the seams with mineral wool and polyurethane foam. (Fig. 13) 6. Paint the walls and cover the floor with a felt carpet. (Fig. 14) Make the hole in one corner where a bunch of cables need to go to the machine room (where the video tape recorders are located) as airtight as possible so that it doesn’t destroy the soundproofing. (Fig. 15) 7. Bring in the gear. (Fig. 16 (and 25)) 8. Attach all of the wall and ceiling absorber panels and bass traps at the front end of the studio. (Fig. 17) Their function is to attenuate first reflections from the walls and the ceiling and to reduce reverberation in the room, but not so much that it kills the room ambience completely. Also build and place acoustic panels against the windows; they will be covered by the slit blinds when they are lowered. (Figs. 18, 19) 9. As there will still remain some problems caused by room modes etc., mostly at the bass end of the spectrum, calibrate the monitoring with IK Multimedia’s ARC measurement/correction system. See Fig. 20. 10. Fix the sound leakage through the outer doors and door frames with new thresholds, weatherstrip and more polyurethane. (Figs. 21, 22, 23) 11. Write an article about the building process for Recording Magazine and hope it will inspire others into making their studios more soundproof, acoustically accurate and thus more comfortable for everyone!
RECORDING JUNE 2011

As you are reading this article, you probably guessed that I eventually managed to get through the to-do list above. It was a lot of work, but actually a little less than I thought it would be; as a bonus I lost some weight, too! Figures 24 and 25 show the completed room from the outside and what it looks like on the inside. The punchline... The question you’re probably wanting to ask me now is, “Well, did the treatment work as planned?” The answer is a definite “yes!” When I’m working in my studio, doors closed, with my usual (not overly loud) volume levels, the Craft people on the other side of the new walls don’t even know if I’m there or not. Vice-versa, I can’t hear any sound from their side. My monitoring is now much more accurate than in any of my previous studios and the stereo imaging is great. And because I’m doing all my daily work in the studio I can use more time for making music, too. Actually, I think that’s what I’m going to do, right now! [Photos continue to page 24—Ed.] Otso Pakarinen (pakarinen@recordingmag.com) is an audio and video producer working happily on all sorts of commercial projects from his new studio space in Helsinki, Finland. Check out Otso’s musical projects at www.ozoneplayer.com.

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Recording - June 2011

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