Genelec 1040a Subwoofer Pairing

[aschen]

Kali 6.2 may be a compelling option for you

 

[10PSPMemSticksForMiku2007]

$500 is about the price range where you can do better than commercial offerings building your own subwoofer with a large cabinet, especially if you are willing to do a folded horn type design, the benefits of higher sensitivity will surpass those from economies of scale that large speaker companies can put into their drivers and amp into simple designs. but even if it's just a simple ported or sealed design it helps to have more volume (size) to get more efficiency and low frequency response.

You can also make efficient use of space by making a box that doubles as a tv stand, or goes under or behind a bed or sofa, or stacking to the ceiling. The space under my bed is 30 cubic feet so I have a pretty good sound in my bedroom without it being in the way. Maybe the answer, without sacrificing your performance requirements, is to make better use of space so the size of the cabinet does not have to be compromised so much.
I realize not everyone wants to go the DIY route but it's something to think about.

Last year, I built a 5.3 cubic ft box ported and tuned to 17 hz for $200 and it's powered by a used amp I got for $20. Comparing the data from Audioholics' review, its SPL and distortion are as good or better than the $500 speedwoofer and the low extension is much better especially in a small room. This is not a great accomplishment, it's just what happens with a bigger cabinet and two 12" drivers vs. one 10".

 

[DVDdoug]

Shouldn’t a true *sub*woofer extend below 20 hz?

I suppose... but subs that have usable low-distortion audio at 20Hz are RARE and expensive. Our ears aren't very sensitive at lowest frequencies so it takes lots of power, usually a big woofer, and a good design.

If you have small speakers you can get a LOT of additional bass by adding a sub that doesn't go all the way to 20Hz.

With a home theater system you (usually) don't get the "point one" channel at all without a separate subwoofer and it doesn't "need" to go to 20Hz either. If you have full-range speakers you can configure an AVR so the full-range goes to the main & surround speakers and only the "point one" LFE channel goes to the sub. And of course, that means pro studios DO need a sub for the LFE if they are mixing surround sound.

"Main" pro studio monitors will go down to 20Hz or lower and they may, or may not, include a subwoofer.

Pro subwoofers used live and in dance clubs are usually "tuned" to go down to around 40Hz. That's approximately the lowest note on a standard bass guitar and it's low-enough for bass you can feel in your body (if it's loud enough). There are usually compromises in speaker design and with certain trade-offs they can make a sub that's more efficient and louder if they don't go all they way down to 20Hz. It's the most logical way to fill a large venue with bass you can feel.

I'm not sure how common 20Hz bass is in movie theaters. I'm pretty sure that most theaters can't. The first Cerwin Vega "Earthquake" subwoofers used in the movie Earthquake (in the 1970s) didn't go that low and they were just playing triggered-generated low-frequency noise because the film soundtrack format (optical?) didn't support low bass. The current model is spec'd at 36Hz.

I built a pair of 15-inch subs in large ported cabinets and I took a similar approach, tuning them to cut-off somewhere in the 30Hz range. I don't remember exactly but they can "rattle the walls" and annoy my nearby neighbors. ...So I don't really take advantage of them because i try to respect my neighbors.

 

[10PSPMemSticksForMiku2007]

This does vary between buildings (obviously) but I think wood frame walls tend to resonate in the mid to upper bass. Depending on the room not much would be needed. I know someone who bought a HTIB and was very impressed with the single 8" sub included because it could rattle his walls. It was quite rolled off at 40hz already, but strong at 90.
In my own room, a hinged door is the only object compliant enough to resonate at 30hz, rattling the latch. I have to leave it slightly open when listening.