Hi,
I am going to build a 3.83 cu. ft. sealed enclosure for a 15 inch subwoofer. Dayton Audio DCS385-4 15" Classic Subwoofer 4 Ohm
Where I live plywood and MDF is about the same price, so I'm going for plywood. Most threads I've read people use 3/4 inch MDF for 10-12 inch drivers, but larger drivers needs thicker enclosures right? I know plywood is stiffer, so 3/4 inch may be enough? Or should I use the thickest plywood I am able to get, which is 7/8 inch? I'm going to use dovels for internal bracing.
I'm also wondering if i should double up on the baffle? If I buy one large sheet of plywood, I will have enough to do it. But I read somewhere here on the forum that if the baffle is too thick, the driver can't breathe properly and it will color the sound.
Thanks!
I am going to build a 3.83 cu. ft. sealed enclosure for a 15 inch subwoofer. Dayton Audio DCS385-4 15" Classic Subwoofer 4 Ohm
Where I live plywood and MDF is about the same price, so I'm going for plywood. Most threads I've read people use 3/4 inch MDF for 10-12 inch drivers, but larger drivers needs thicker enclosures right? I know plywood is stiffer, so 3/4 inch may be enough? Or should I use the thickest plywood I am able to get, which is 7/8 inch? I'm going to use dovels for internal bracing.
I'm also wondering if i should double up on the baffle? If I buy one large sheet of plywood, I will have enough to do it. But I read somewhere here on the forum that if the baffle is too thick, the driver can't breathe properly and it will color the sound.
Thanks!
I would definitely go with the ply. MDF is a bit easier to work with in some ways, but ply should be lighter. 3/4" is fine, once you brace it properly.
Doubling up on the front baffle will allow you to flush-mount the driver, for a nicer look. I'd consider doing this if I was building this subwoofer for home use.
Doubling up on the front baffle will allow you to flush-mount the driver, for a nicer look. I'd consider doing this if I was building this subwoofer for home use.
We built a push-push dual 10” subwoofer out of well braced 15mm plywood, and i had to go to heroic efforts to get any panels to vibrate. A single 15” won’t have the advantage of active vibration cancelation so you will be loading the box to a much greater extent — there are huge advantages to push-push subwoofers. 15mm is certainly a more suitable material than ¾” MDF, either would need to be well braced. Yes, doubling the baffle is a good idea.
dave
dave
As the robot who built the boxes Dave mentioned, as well as some custom gonzo boxes for a local hifi / car installer and others, I can attest that the combination of push/push and thorough bracing is definitely worth the effort.
And definitely BB ply rather than MDF; a single layer of 18 with bracing could be enough - although I think you'll want thicker than just dowels. For a 15" woofer, I wouldn't worry about it "not breathing" if baffle doubled up, but honestly, I think that time / material is better spent on bracing.
And definitely BB ply rather than MDF; a single layer of 18 with bracing could be enough - although I think you'll want thicker than just dowels. For a 15" woofer, I wouldn't worry about it "not breathing" if baffle doubled up, but honestly, I think that time / material is better spent on bracing.
plywood
Hi there: Plywood! MDF is snarky stuff to deal with. No advantage to MDF and if it gets any water on it, it swells-up (unless you want to create 1" MDF from 3/4" MDF). Baltic birch plywood, while good material, sells for over a hundred dollars for a 5x5 foot sheet here in my area. ...regards, Michael
Hi there: Plywood! MDF is snarky stuff to deal with. No advantage to MDF and if it gets any water on it, it swells-up (unless you want to create 1" MDF from 3/4" MDF). Baltic birch plywood, while good material, sells for over a hundred dollars for a 5x5 foot sheet here in my area. ...regards, Michael
I built one the same size. Use 1" ply but, do it by gluing two 1/2" inch pieces together. The 7/8 and 1" ply tend not to to be straight(warped) and require some serious effort to get straight walls. A T-brace above the woofer works pretty well. The sad part is that even a well braced 1" ply woofer box will vibrate at higher volume as it is just tough to stop. It will be the woofer end that does it. The t-brace works.
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I usually pay $40.00 a sheet for the Russian made Baltic birch. Not quite as good as the stuff from Finland. You might want to find out who supplies the local kitchen cabinet makers.
They may have a minimum order of typically $150 and a delivery charge on small orders. But should allow pickup. If you need a pickup truck for a few hours Home Depot often has them.
They also used to carry the Chinese birch plywood. But unfortunately it cost much more than corregated cardboard, which is a bit stronger.
This is were using a push-push pair really helps a lot because you have active reaction force cancelation abd the load on the box is dramatically reduced — well done probably by 90% or so.
Use 2x10 instead of a 12, 2x12 instead of a 15, 2x15 instead of an 18.
dave
About the same as here, but we quit using it when the quality became hit or miss. We now use sheets sourced from MurphyPly in Oregon. Quality Baltic sourced cores which they put maple surface plies on. 4x8s are about twice as much as the BB, with much higher quality, much less waste and typically better yield from th elarger more convienient size. We try to use 15mm as much as possible but do use 18mm and 12mm when called for.
dave
The biggest issues we had with the spotty QC on the Russian BB was on the face veneers - increasing occurrences of large foot-ball patches, smaller unpatched pinhole knots, and mineral stains, etc - all cosmetic. In over several hundred sheets of the 5x5s I only ever had maybe 3 that had delaminations of glue joints, which the vendor immediately replaced.
But yah, the Murphy Multi-ply have a much nicer maple veneer face.
But yah, the Murphy Multi-ply have a much nicer maple veneer face.
Can you explain what YOU mean by a push-push configuration? Both drivers with frame/magnet inside the enclosure running in phase or is one driver flipped? Forgive me if I'm being naive here. As always I appreciate your time and glad you're seemingly back to good health Dave.
Wes
Here is a thread on the subject: Force Cancellation: X, Y or Z axis?
And i copy my post from it below.
dave
And i copy my post from it below.
dave
I built a set very similar to what you are describing with 2 CSS SDX10 per box. Performance was outstanding.
Mount the drivers on the side, a 90° turn of the box gives front & back. Side mounting, unless the box is way out from the wall (or way up in the air) is the only arrangement where the 2 woofers will get ~equal boundary loading. As radiation at these frequencies are omni-directional the direction makes little difference in that sense. And a recent FAST build where we let an associate go at that to design a passive XO, ended up with the side mounted woofers XOed up near 450 Hz — mind you much smaller woofers.
The only picture i have is of the push-push nature shown from inside:
We built the raw box out of well braced 15mm BB. You could easily pick up both boxes with two hands. Load the drivers in and each box was Good news a 2-man lift (or 1 guy with a strong back). They never got finished as Chris sold them to raise cash while i was in the hospital — the new owner raves over them.
I did a test with a mechanics stethoscope to check box resonances. I turned the system up to uncomfortably loud, then turned off the satellite amps and then added another 10 dB (bass amps were probably haevily clipping). I was able to get the top moving, alll the other panels were quiet. I figures a corian (or similar) top would fix that.
Good news — CSS is back in business under new ownership with SDX10s appearing again new years end, and i am already working on getting a new set for V2.
I did 2 plans for these, ended up building the smaller ones, i figure being sealed that i could EQ them to suit…sim-wise the larger box is closer to ideal Q.
http://www.planet10-hifi.com/downloads/TwinSDX10PPP-woof-230712.pdf
3d visuallization of the bigger box:
Who'da thought AR knew what they were doing with the AR-9. So long ago. Luck?
Re plywood: just buy void free 3/4 fir decking grade. Unless you insist on paying too much. We really don't need to import plywood to the USA; we need to be pushy consumers and seek out the good stuff made here. HD and Lowes won't be any help on this. You need a real wood products vendor.
Re plywood: just buy void free 3/4 fir decking grade. Unless you insist on paying too much. We really don't need to import plywood to the USA; we need to be pushy consumers and seek out the good stuff made here. HD and Lowes won't be any help on this. You need a real wood products vendor.
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