QSC K-Sub(s) under a stage?

Simon Eves

Sophomore
May 12, 2013
189
0
16
Following on from my other "how big a rig for this room" thread, I'm now hoping (mainly for financial reasons) to keep the existing mains and just supplement them with a sub or two.

I looked around as to what was available to rent, and of course most places offer QSCs. I wasn't previously aware of the K-Sub, and while it doesn't seem to have universally good reviews, the thing that appeals is that it's small enough to fit (on its side) under the front extended section of our stage, which is 3' deep and 18" off the ground. The K-Sub would therefore have 3" above it to the 1/2" plywood stage floor, and about a foot behind it to the vertical front of the solid stage. There is a velvet curtain across the front, as that area is normally used for storage, but I can remove that near the sub(s) if necessary, although I doubt it has much effect on the frequency response.

We can afford to rent one, perhaps two, for the month of tech and performances of the show in question, so I'm wondering how well they would behave under there, in terms of cooling and resonance. I am going to rent one for a day and try it out. I have access to two other fairly large home cinema subs, some no-brand thing I've used before but only for sound effects, and a 2008-vintage SVS cylinder model. I'm worried that neither of those have the headroom or whole-band-whole-show tolerance of something designed for PA use, though, and of course neither of them would fit under the stage.

Thoughts welcome, as ever.
 
Putting your sub enclosure in an enclosure will change the sound. Will it be bad? Hard to say. There may be some cancellations or summations that occur in the chamber behind the cabinet as they reflect out. This will vary by frequency. It may not be enough to even be noticeable.

As far as cooling goes, the unit is fan cooled, so as long as there is some air circulation, you should be ok. If you completely enclose the area with your velvet covering though, the cavity may warm a bit during operation if you push the sub hard. Keep an eye on it the first day or 2.
 
Turns out that the vertical clearance under the stage is 1/4" less than the height of a K-Sub on its side, so the idea is officially scratched. The upside is now I get to use KW181s instead as they're the same price to rent! ;)