DIY SUB worth it?

tryrrthg

Originally posted by Schris22
Thanks for all the input.

I saw the plans thanks.

I think i can still do 4 cubic feet and raise the tune to about 20.5 that puts the 4 inch port to just about 17....

Not sure how much difference the 1 hz change will bring...but I'm sure it'll be fine for HT.


I think almost everything is tied up now...

Just should I get those feet from PE? I don't think I'll get the casters after all. Is there another place to get feet?


Chris

well whatever you do keep those plans in mind when you design the box. They are braced well and plenty of air flow inside the enclosure.

you won't need to buy any feet/spikes, just use some scrap wood. Your box will weigh over 100 pounds, it won't be going anywhere.

michael_w

I used a stack of two 3/4" mdf squares for my feet then a 2 inch caster attached to the squares. Mine is down firing so I needed it to be that high off the ground. Be careful when you flip it back onto its feet after putting the feet on.... when I rolled mine over by myself a caster shifted and dropped the sub about half an inch. Two mdf legs just shattered (peeled the mdf into layers) and I had to make more

I used two 4" flared ports like the ones linked to and left them the stock 18" long. As is they are a really snug fit and it might be hard to find a piece of pvc that would be the same to replace the middle piece. You will also need some pvc cement to glue the ports pieces together. (flared ports are 5 pice construcion) Careful with the cement though because the fumes off it are CRAZY. Definatly do it outside and try to breathe as little as possible when doing it because that stuff just burns your nasel passages and throat, or you could do it the smart way and use a respiorator.

Schris22

Just ordered the sub and amp and everythign else from parts express...

that means just pvc cleaner/cement, whatever finish, and gorilla glue I need from HD.

Where do I get all the mounting screws for the speaker/port and amp? I'm planning on using glue/clamps to seal everything...

Chris

Schris22

about to go to the HD....my list ok as far as in what to get? I got a 10% off coupon so trying to get everything now...I'm pretty sure this is it...but just in case

Chris

burdette

If I can find them, I have hurricane nuts (or speaker mounting screws) from PE for mounting the driver.

I don't remember if mine are #8 or #10 - but I bought 50 hurricane nuts and used only 8 to mount my AV12. I used them with bolts I purchased at Lowe's - but frankly, if I had it to do again, I probably would have used some plywood for the inner baffle and just used speaker screws (I have some of those, too). The hurricane nuts (or T-nuts) are better than screws if you plan on taking the driver out repeatedly AND if you're mounting to MDF (which will chip away if you keep taking screws in and out). But if - like me - you just plan on mounting the driver and don't need to remove it over and over, I think I'd use plywood as the 2nd (and 3rd?) layer of the baffle, and use screws.

If you're interested in either the hurricane nuts or speaker mounting screws, let me know. This link is for 1" screws - I *think* I bought some longer than that (1.5"?) but I don't remember.

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=081-1080

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=081-425

I'll send you 8 plus an extra 1 or 2. If you WANT, you can send me a couple bucks worth of McD's gift certificates (to offset the shipping) and my kids can get ice cream.


EDIT: the pics wouldn't load because they're already on the forums from long long ago. I'll see if I can find the thread:

http://clubpolk.polkaudio.com/forum/showthread.php?t=8803

This is the 2nd pic from the old thread:
Here is an 'internal' view of my AV12 mounted to the baffle. The flat piece of the baffle sticking out to the left WAS intended as a nifty 'holder' for the separate box I built for the amp. But, this driver was just too powerful for that. The amp box vibrated excessively when the sub was pushed even moderately, so the amp has to sit on the floor. In fact, the 'shelf' itself vibrated to the point that I just cut it off.

This is the first pic from the old thread:
What the heck, I'll include another pic... this is the original design with the amp box sitting on its shelf. When I designed this, I had no idea the raw power the driver could create.

Schris22

Very informative. i was planning on just going to HD or something to pick some up. Do they have hurricane nuts?

So if I predrill the holes and screw in speaker screws just make sure not to do it too many times right? otherwise use the hurricane nuts and some bolts to match?

Chris

burdette

My opinions....

Ya, assuming you don't need to take the driver out and put it back in repeatedly, I think you're fine using screws with a good, aggressive thread-depth. I would use plywood for at least one of the layers of the baffle. But that is just me - I tend to not like the durability (or lack thereof) of MDF screwholes.

If you ARE going to install/remove the driver a lot, then I think T-nuts (or hurricane nuts) and bolts would be the way to go.

I know you can buy T-nuts at HD. I don't know about hurricane nuts. I've never looked. I got mine from PE.

I am building a subwoofer for our church using a Peavey 18" Lowrider driver. Peavey expressly recommends AGAINST using MDF for the enclosure, and specifically recommends at least 3/4" (1" is better) plywood of at least B/C grade.

michael_w

I used hurricane nuts with my driver and I find they not only look better but provide a more reassuring seal and fit because you don't have to worry about stripping the screw in the mdf as much. I got mine from Creative Sound Solutions.

Ron-P

I think you're fine using screws with a good, aggressive thread-depth. I would use plywood for at least one of the layers of the baffle.

This is what I did for my DIY Sonosub. It's a 36"x24" diameter sonotube with a 15" Tempest driver and two 3" flared port kits tuned to 17Hz. I used mdf for the inner cap and 3/4" plywood for the outer cap. It worked just fine, I built it over 1.5 years ago and have yet to remove the driver.

Schris22

I shouldn't use plywood for the back panel (amp mounting) correct? Just thought about how front people use plywood for the first 3/4 to use screws...but amp uses screws too. Is this not as much of an issue?


Amp came in today...it is purty

Thanks,

Chris

Schris22

stuff from parts express came in...just got to wait on AV12 but i think i can start building and mount it later...but so far everything is awesome...the 4 inch port is much bigger than expected.. comes out to 7 inches on the flares...huge.

Chris

Schris22

another question....i know i know...

the amp connects to the sub through the red and black wires. the connection on the end reminds me of an Atc? fuse connector. is there anything else i have to buy to connect the sub to the amp?

chris

Schris22

well no sub in yet , but about to start on day 2 of the sub with a friend...

so far got 4 sides of the box put together and still need to attach one more shelf brace, the two sides, a lil more foam for the other sides, mount amp and sub and finish and do a grill as well.

tough work....oh well today will be fun...I'll get some pics for yall later


Chris

Schris22

talking to my self but thats ok I'll get pics of the construction up soon....

6 coats of primer....and 5 coats of paint to make it look decent....Gonna take a break and get started on wed. Have to figure out how to construct a grill and figure out what kind of legs I want to make...most likely wooden square bocks of Plywood...

Chris

michael_w

Sounds good... I myself am taking my sub apart for paint today. At 4" the ports don't sound to big but I too was suprised when I saw mine. That 7" flare really makes them look huge.

Make sure to take lots and lots of pics. Usually one of the dissapointments when I'm building something is that I didn't take enough pictures to really capture the process.

Keep us posted!!