Re: Under the bed subwoofer system
Kinda surprised only one has responded to this...
We used to have a waterbed with a so-called “under-dresser,” so I can picture what you’re talking about. It had a “dead space” tunnel right down the center of the bed, end to end – perfect for a “stealth” subwoofer. It sounds to me like a pretty innovative idea, especially since you’re challenged for space. The only downfall I can see is that you won’t be able to move it around for optimal response, which is typically near a corner, but the space-saving probably makes that a worthwhile trade-off.
I know just enough about building subs that I can give you some basic advice. Since your box will very long, with a short height and width, you should be able to get away with using 3/4” MFD. However, I’d use a 1” piece for the baffleboard.
As far as what driver to use, first determine how many cubic feet (or liters) your box can have. I think I’d go with a 12” driver, unless that will put the bed too tall. Considering how small your room is – about 800 cu. ft. – just about any decent driver will do the job. You might look at the Adire Shiva, a great driver for the money.
I don’t even think I’d fool with a ported design, since a single sealed 12” will be more than enough to get all you want in that room. I’d design it so that the driver fires at the head of the bed (i.e., the end near the wall), not at the foot, which fires into the middle of the room. That way you can get some boundary reinforcement, even if you don’t get the advantage of a corner.