The best sounding subs need a solid box...

Danny Richie · « **on:** 19 Apr 2008, 12:24 am »

Here's a good one. This is a 1.5 cubic foot sealed box for a single SW-12-04 Direct Servo sub.

This is the inner box. It is built from 3/8" thick MDF on four sides.

The braces are 2.875" apart and are made from 3/4" MDF. The woofer mounts in the front (as shown) and the plate amp will mount on the panel on the rear.

Next some 3/4" wide and 3/8" thick MDF strips are cut and laid in line with the braces below.

When this is set into the outer box it leaves a 3/8" thick space between the walls.

Next five sides of the outer box is built around it.

Additional 3/4" thick pieces cover the front (where the woofer mounts) and the back panel where the amp will mount.

Then comes the fun part, pouring in the sand. Shaking it, rocking it, and beating the sides with a rubber mallet insured that the sand was forced in as tight as possible and as much as it could hold.

Then the last panel is glued on sealing it up.

So far, so good. It is a rock solid box.

Next I cut the amp hole in the back.

I also plan to seal the back of the amp from the inner air space.

More to come...

jmc207 · « **Reply #1 on:** 19 Apr 2008, 01:30 am »

I Love It! Great pictures.

TomW16 · « **Reply #2 on:** 19 Apr 2008, 02:10 am »

Wow, I hope that is a pallet that the sub is sitting on because you're going to need a fork lift to move it.

WGH · « **Reply #3 on:** 19 Apr 2008, 02:15 am »

Really nice inspired design. Is this a personal project?

Danny Richie · « **Reply #4 on:** 19 Apr 2008, 02:35 am »

Quote

Really nice inspired design. Is this a personal project?

I guess so. I mean, I have all of these really bad to the bone Direct Servo subs in stock and the amps are now in stock as well. So I figured I better get a few of them built out so that I have them to demo.

When I am through with it I will also make the plans for it and the non-sand filled version available for those that would like to build this type of box.

satfrat · « **Reply #5 on:** 19 Apr 2008, 04:51 am »

You had me going there with that 1st picture Danny with those thick center ribplates being surrounded by such thin side walls. It didn't make a lick of sense to me but I should have known there would be much more to it.

I like that design a lot,,, makes me wish I needed another sub.

And thanks for sharing your design with pictures,,, very nicely done indeed!

Cheers,
Robin

RAW · « **Reply #6 on:** 19 Apr 2008, 06:49 am »

Nice work Danny

brj · « **Reply #7 on:** 19 Apr 2008, 07:03 am »

Quote from: TomW16

Wow, I hope that is a pallet that the sub is sitting on because you're going to need a fork lift to move it.

A perfect compliment to the 350 lbm big blue amp!

Nice work, Danny!

pbrstreetgang · « **Reply #8 on:** 19 Apr 2008, 07:26 am »

Amps

Danny Richie · « **Reply #9 on:** 19 Apr 2008, 01:51 pm »

You got in Marbles.

The weight isn't too bad. The total amount of sand was a little over 10 pounds. I even sifted out the small rocks.

It took some extra time to build it this way, but it was pretty easy.

Bill Baker · « **Reply #10 on:** 20 Apr 2008, 02:09 am »

Excellent enclosure Danny

I did something very similar with a custom pair of large stand mount speakers I built for a customer about 9 years ago. Last I heard he still had them and still lovin 'em.
It does look a bit time consuming but well worth it in the end. For a subwoofer, I can't imagine a better way to go.

I have 4 50 pound bags of sand laying around. Now I know what at least one bag will be used for

drmike · « **Reply #11 on:** 20 Apr 2008, 10:50 am »

danny,
could you possibly give the dimensions and cutouts?
thanks,
drmike

mcgsxr · « **Reply #12 on:** 20 Apr 2008, 01:22 pm »

Nice approach, guess folks better invest in a hand dolly to cart those about the house!

Danny Richie · « **Reply #13 on:** 21 Apr 2008, 01:33 am »

Quote

could you possibly give the dimensions and cutouts?

I am going to draw the whole thing out.

Quote

Nice approach, guess folks better invest in a hand dolly to cart those about the house!

I weighed it today. The empty enclosure weight was 66 pounds.

Christof · « **Reply #14 on:** 1 May 2008, 12:33 pm »

Has anyone completed one of these subs yet? Post some pic's and let us know how these bad boys sound. I'm still plugging away on Rob's 4 boxes.

nodiak · « **Reply #15 on:** 1 May 2008, 11:00 pm »

Christof,
Sorry this won't be totally satisfying but here goes, sorry no pics. I have a Rythmik DS12-04 sub and last month switched the stock aluminum cone driver for a GR 12-04 paper cone driver. Made a smaller 1.5cf cab. No sand damping but 4 of 6 walls are 1.5" mdf/BB (incld. woofer and amp baffles), BB bracing. Am using original Rythmik amp, not new ones for GR drivers.
At first it seemed a bit softer sounding but broke in to be nice and clear and dynamic. I didn't keep the alum. driver for comparisons tho (sold it too soon) so can only go by memory.
The GR driver does seem more open and lively. The lighter cone does however have less power handling as I bottomed it playing Battlestar galactica movie, just a light click tho.
I'm into Rythmik/GR subs now, and would ultimately like 3 per side OB drivers, or 2 per side 8 ohm in sealed, but will probly go with another 4 ohm for stereo (room and $ thing).
Rythmik subs are the best I've had, tight and deep. Hope you get yours done soon.
Don

drmike · « **Reply #16 on:** 13 May 2008, 02:01 pm »

dimensions and cutouts?
thanks,
drmike

KS · « **Reply #17 on:** 17 May 2008, 12:37 am »

What is the minimum size for the side with the driver cutout?...how much wood around the driver is needed to support it, and no acoustic problems?

How would 1" MDF work, internally braced, and lined with No-Rez? 85% of the effectiveness of the sand box?...50%?...95%?

Danny Richie · « **Reply #18 on:** 17 May 2008, 05:23 pm »

The diameter of the hole needed to counter sink the driver is 12 and 9/16 inches. The through hole is 11"

I used two layers of 3/4" MDF for the front baffle. Counter sinking it removed 5/8" of depth leaving 7/8" thick material beneath it.

A well braced box lined with No Rez would still be very effective. I'll have to build one out to compare it to the sand lined box.

AUDFILE74 · « **Reply #19 on:** 20 May 2008, 04:29 pm »

Hey Danny, could you make one of the enclosure drawings for a sealed enclosure with 2 gr/rythmik 12-08 subs in separate 1.6 cu.ft airspaces?