Subwoofer Project AKA Subzilla

[David_NC]

I love bass. I'm not referring to what one gets from cranking up the bass control but to real, effortless, deep bass. I have a few subwoofers already; my fave is an SVS SB12-NSB, which I use in my primary listening area. It does a great job and is connected to my HT and stereo systems.
I wanted something larger than the smallish dual 8" RBH sub I use in our HT downstairs, which got me thinking about building one. I have amplification taken care of with a QSC pro amp that will provide 900 watts, so building a subwoofer looks even better. A friend recently built a couple subs and offered to cut all the panels on a CNC machine. The drawings are complete, and I just need to pick up a sheet of MDF. Once he's finished, I'll have a stack of panels, and the fun will begin!
On the recommendation of a member here, I ordered a Stereo Integrity SQL series 15" dual voice coil driver. It arrived yesterday, and this thing is a beast! I obviously had to try it out a bit, and even without an enclosure of any sort, I can tell this will provide the deep bass I want. For some reason, I didn't get a pic of the front of the driver, but there's one on their website. Below are the pics I did get. One of the more impressive things I noticed is that the tinsel leads are not hanging but are attached to the spider, unlike on most drivers. There's also one with a glimpse of the VC's. I'll update this thread as the build progresses.

 

[swechsler]

One of the more impressive things I noticed is that the tinsel leads are not hanging but are attached to the spider, unlike on most drivers.

That's a nice touch. I'm sure they figured that with the amount of excursion that this subwoofer is capable of (XMax: 28mm!), the odds of the tinsel leads hitting the cone were good without them being glued down.

 

[David_NC]

Finally, progress! I got the cabinet cut (designed and cut on a CNC machine by a friend) and assembled. I couldn't wait to finish it, install binding posts, etc, so I ran a speaker wire through a hole that will contain a binding post, mounted the driver, and connected it to a QSC CX6 running bridged @ 900 watts. All I can say is damn, this thing is impressive. I have a few 'test' tracks with really deep bass but that also sound good... none of this boomy nonsense here! Playing Felix Hell's Fugue from his Organ Sensations album (I know, a cheesy album name), the pipe organs have that affect that real pipe organs can have. Being able to feel sound before hearing it can be a strange feeling, if one hasn't experienced it before. I know I've previously said that I like to be involved in my music. Part of that is picking out detail, but another part is more basic - felling it. So far, I'm def. being involved with this... goosebumps from several tracks prove this.
The cabinet obviously needs a good bit of finish work. So far, I haven't decided on finish - wood veneer, paint (satin or textured), or whatever. There's another piece that will mount to the face of the box so that the driver doesn't extend as far and to reinforce the cabinet. The issue is that the specified overall dimensions don't appear to be accurate; I even allowed another 1/4" in size, so this will take a bit of work. The pics also don't show the rear panel's bracing. The one brace that can be seen seems to make this box extremely rigid; there's no movement or flex from the driver or when I stand on it. Part of this is due to the material, I'm sure (3/4" MDF), but part of the credit for this has to be due to its small size. It's only a roughly18" cube. Two cubic feet is the recommended sealed volume, so that's another plus. As for power, these QSC amps seem to have near limitless amounts of it. I know that's not true, but I've cranked this thing (with the main speaker's amp turned off) just to get a sense of what it can do, and I never saw a clip light. Obviously, I'm not trying hard enough! Seriously, I pick these things up in near mint condition for $25 to $75 and have yet to have an issue with the three I've purchased, other than having to tweak the bias on one. If 900 watts isn't enough - I believe I read 1kW continuous / 2kW peak are the driver's ratings - I'll pick up one with a bit more power; $200 or so will get me 2kW/3kW (8/4Ω).
Note the 19" rack-mount amp sitting on top for size perspective.

 

[Hobie1dog]

Thanks for the pictures and SQ report