Genelec’s 7360A: it matters where you put a subwoofer, but in relation to the room modes rather than relative to the other speakers and the listening position.
After running the research gauntlet and consulting with SOS and reading Hugh’s excellent review [SOS July 2014: www.soundonsound.com/reviews/genelec-ones], I’ve decided to upgrade my studio significantly with a pair of Genelec 8341 The Ones monitors. I’m probably going to run them for a while with no subwoofer, but I’m already researching what it would mean to add a sub (Genelec 7360A) and to implement it spatially in my room. In an image in Genelec’s GLM manual, they are suggesting a placement that would have it (if one draws a straight line from the woofer port to the listener’s ear at the listening position) sending the direct sound waves right through the underside of the mixing desk and, for me, through my substantial analogue console. Is it perhaps not an obstruction issue because the sub‑80Hz frequencies aren’t so directional?
SOS Forum Post
SOS Technical Editor Hugh Robjohns replies: We’ve written about choosing and placing subwoofers a few times, and my SOS April 2007 article (www.soundonsound.com/sound-advice/all-you-wanted-know-about-subwoofers) is a good primer if you (or anyone else reading this) requires one.
If a subwoofer is set up correctly, and it’s a good, low‑distortion design, then you should not be able to tell where it is just by listening with your eyes shut!
As for the specifics of your case, the wavelengths are so long at low frequencies that the sound waves bend around most furniture as if they weren’t there, so you don’t need to worry about obstructions in the direct path at all. You might need to worry about the space below a desk being a resonating chamber, though — particularly if the desk has solid sides.
Thankfully, one of the advantages of a sub is that you have quite a lot of latitude in where you put it (unlike the main speakers, which have to be in an equilateral triangle from the listening position). So that allows you to locate it in the optimum position relative to room modes: if you find a good spot along the wall behind the main speakers, that’s great, but if it works better in the room on a side wall that’s absolutely fine too. If a subwoofer is set up correctly, and it’s a good, low‑distortion design, then you should not be able to tell where it is just by listening with your eyes shut!