Acoustic Dampening

[Maceo23]

I'm about to start building a pair of sealed TC-12 subs. I was wondering what is the best type of acoustic dampening. Should I go foam or stuffing? And how much should I use in a 2 cube box?

Thanks Guys

[deneb]

Wow, I've got a project exactly like yours going right now! I also have a pair of the TC-12 drivers and am building 2.5 cf (gross, I figure 20% loss when factoring in driver and bracing volume) sealed boxes for each of them. I'm building them out of Birch plywood with MDF bracing. I'm using polyester fiberfill for stuffing, 2.5 lbs for each cabinet. I read an article (can't find the link, saw it on avsforum) that said polyester fiberfill is about the best stuff (if there is a 'best') to use for a sealed enclosure, and adding 1 - 1.5 lbs. per cubic foot of displacement makes the driver think it's in a roughly 25 - 30% larger enclosure. So, any fabric store should have the polyester fiberfill (picked mine up at a fabric store just a few hrs. ago), or Wal Mart if you can stomach that place. I'd use 2lbs in each box.

What are you using to power them? I've got a Buttkicker for each driver. Someone on the TC sounds forum just built a 2 cf sealed box for a TC-12 and was impressed with it's output, so I'm pretty stoked!

Edit: Found the link to the stuffing article: http://www.diysubwoofers.org/talksho...ages/41415.htm

Also, I asked the same question you have over on the avs forum as well: http://www.avsforum.com/avs-vb/showthread.php?t=839327

[Maceo23]

Thanks for the reply. I'm also using the buttkicker amp. Althoug, I'm using one to run both subs. I'd go two, but at the moment, funds are stretch a little thin. I'm sure I'll add a secong one in the future though. Make sure to post some pis when the project is done, I'll do the same. HOpefully I can get started next week.

[Maceo23]

I meant PICS

[deneb]

Well, I just finished my dual sealed TC-12 project. Two TC sounds TC-12 drivers, each in an ~2cf enclosure (net), with 2lbs. polyfill stuffing each. It was certainly a learning experience, and there are a few things I'd do differently now that I'm a bit wiser. It's a lot tougher than I thought to build something as simple as a box. Getting it all squared and getting the panels all to line up is a challenge, at least to a first timer like me.

Boxes were built out of 3/4" birch plywood, with MDF internal bracing as well as MDF panels attached to the inside of the birch panels. The front baffle is a double thickness of birch ply. The edges are lined with hemlock, since my Dad had scrap MDF and the hemlock; I only had to buy the 4X8 sheet of plywood. Here's a full parts list:

4X8 sheet of birch plywood
Hemlock trim
MDF for bracing
Spikes:
http://www.partsexpress.com/pe/show...tnumber=240-715
Gasketing Tape:
http://www.partsexpress.com/pe/show...tnumber=260-542
Binding posts:
http://www.partsexpress.com/pe/show...number=091-1245
Home Depot 12 gauge speaker wire
Polyester fiberfill from some fabric store
T-nuts
Elmers wood glue
Minwax pre stain conditioner, stain, and poly coating

Finish: Sanded cabinets with 150 grit with a palm sander, then 220 grit by hand. Applied a coat of the pre stain conditioner as birch is a porous wood. Then two coats of natural stain, followed by 3 coats (400 grit sanding between coats) of clear semi-gloss poly coating. Overall, they look pretty good, but I discovered what a lousy sander I am, definitely an aquired skill. They sound MUCH better than my old subs, an Adire audio Rava and an Outlaw LFM-1. Those weren't bad subs, but I've definitely taken a big step up. The new subs go deeper (flat to 20 hz in room with output below that according to my SMS-1 and my room, which now has a lot of vibration), louder, and cleaner with more detail. In fact, my mains even seem more detailed, but that might be psychological. At any rate, it's obvious that the TC-12 is a great driver!

I'm attaching a few pics of the raw, assembled cabinets as well as the finished cabinets in their new home.

Next step: Getting GIK bass traps next week, looking forward to getting those set up. I also managed to strip one of the T nuts, so that will have to be fixed.

I'd post pics, but for some reason when I click 'manage attachments' I get a window that tells me I don't have permission to post pics.

Pics can be viewed here: http://www.avsforum.com/avs-vb/showthread.php?t=849814