Sealed music sub - 12 inch or 10 inch? (1 Viewer)

[Junior]

Hi everyone,
I originally made my debut in the DIY section about a month ago only to realize that was for advanced users. I am ready to build a sub but have couple final questions. If this belongs in the DIY area please let me know=). Ok I pretty much got it figured out down to this:
q = "tightness" of sound, or lower q = better for music
Smaller drivers = smaller enclosures = lower q with same enclosure as bigger drivers.
Smaller drivers = not as low frequencies
For music, extention down to 40hz is adequate.
I hope these are correct or somewhat true and if not please advise.
For many reasons, (transient response, ease of build, ect.) I am planning to build a sealed sub. My sub will be used for 99% music, 1% other. Size is important to me, I would like it no bigger than about 25 liters give or take a bit. Originally, I was thinking of building the 25.5 liter shiva sealed as specified by adire on pg 12 of http://www.adireaudio.com/Files/Seal...plications.PDF
However I got to thinking maybe if I used a 10 inch driver instead, I could get tighter sound in a similar size enclosure in exchange for low end extention (which I only need to 40hz or so anyway...correct me if I'm wrong or you advise otherwise=)). So, what do you guys think? Should I build the shiva sealed? Use a different 12? A different 10? (If you suggest the 10 inch driver I need suggestions and plans). My budjet is $225 - assume the cabinet is free coz I can have someone do me that favor=) lucky me. I was originally planning the shiva 25.5l with a apex jr amp. SPL's is not important to me, my primary concerns are size and performance on music, and price. Any and all advise appreciated=). Thx for reading my post
-Junior (or Ken)

 

[Jack Gilvey]

Well, you want a sub that's good for music, and you pointed out that "lower Q = better for music", yet you're asking if a Q=.95 (the highest of all the Shiva apps, and probably over 1.0 when the voice coils get warm))would be good? I'd say "no". I tried my Shiva in a 30L cab, no-go.
If you can go to 30L or so, try the Dayton 12" DVC from Parts Express, it will work better in a small box with stuffing. Here's what I did.

 

[Brian Bunge]

Jack's suggestion for the Dayton 12" DVC is probably your best bet for a 12" driver.
If you wanted to go with a 10" driver you could use ACI's SV10 in a 28L enclosure stuffed with 1lb. of fiberfil. Assuming 100% stuffing gives you an average of 20% more perceived volume this would be similar to an unstuffed 34L enclosure. Using the free WinSpeakerz demo for the SV10, I'm getting an F3 around 35Hz. Using a 250W amp you won't hit the driver's Xmax until you get down to the 17-18Hz range.
Edit: Qtc is around .67 in this alignment.
I built a 42.5L sealed enclosure using this driver for a customer of mine and she has been quite happy with it so far!
Brian
P.S. This driver is currently on sale for $99 ($20 off).

 

[DerrickN]

Brian,

Can you provide the link to a 42.5L sealed enclosure. I've searched ACI & subwoofers.com website and couldn't find any plan. One thing that is nice about Adire Audio is that they provide a very nice detail plan for all their drivers.

Thanks

 

[Brian Bunge]

Derrick,
There is no link. I simply looked at the suggested alignments and played with the sims using several programs and came up with enclosure dimensions that my customer was happy with. She's using the sub in a 2-channel setup in her bedroom, I believe.
I ended up using a 16" external cube. The walls were 3/4" MDF with a double thick baffle. I used a 3/4" MDF vertical brace with a 10" circle cut out of the middle that connected the sides, top and bottom. I then uses a few pieces of MDF to connect the center brace to the front and back panels.
If you'd like to see a few pics of the completed sub you'll find them Link Removed.
Brian

 

[DerrickN]

Brian,

Thanks for the info. The sub looks exceptional and outstanding. I've to say that you're very talented with your craftmanship.

Derrick

 

[Junior]

Hey thanks for the feedback! I think I will go with the SV10 as recommended due to its smaller size and much better qtc than the shiva in a similar sized box. I'll probably go for something slightly over 1ft ^3 (aiming for around .7 or so). Is it really important to have a plan or could I just build any box with the right volume and bracing? Also, what tools would I need to build the cabinet? (No tools atm - at the moment). Does anyone know how long this sale will last? Also, is the apex jr an ok amp or would it be worth it to get the partsexpress 250W? "super loud" isn't that important to me "loud enough" is fine, but quality is important, and if this makes quite a difference I might put down the difference and go for the 250W.
-Junior

 

[Brian Bunge]

Junior,

The 1ft^3 (28.3L) enclosure yields a Qtc of .72, 1.1ft^3 gets you .69 so right around 1ft^3 or so should be perfect. No, there's no need for any specific "plans", just make sure you allow for the volume of the driver, the amp, and the bracing. I think a 14"-15" exterior cube with a couple of cross braces would be perfect for you.

A router with a circle jig is the most essential tool, IMHO. Also a small tablesaw or a skil saw with a good straight edge would be good to have also. If you have a friend with a tablesaw then they could cut the wood for you. Other than that, a couple of bar clamps would be very handy for gluing up the enclosure.

If you need any help with the design let me know.

Brian

 

[Jack Gilvey]

The smaller amp should be fine for a 10". The 250 watt amp would be a good match for the higher-displacement 12" DVC I mentioned for more output.

 

[Brian Bunge]

Jack,

The 250W amp would also be a good match for the SV10. But the Apex Jr. should be fine as well.

Brian

 

[Junior]

Thanks for all the help, all my questions are answered! I'm going to order the 10 incher as well as having a friend cut out some MDF for me, I'll be doing the finer details myself though. The amp will be the apex jr. I'll be sure to post results, in the "photo summary" style if at all possible (but unlikely).

Once again, thanks to all!

-Junior

 

[Junior]

Hey everyone
I FINALLY started building the cabinet, but not very much. So far, I got the holes cut for the amp and the driver and thats it, nothing glued. Now for the amp, I only cut one hole so the amp isn't flush with the outside...I thought it was fine as long as it is airtight, so it only hurts asthetically. However, for the driver I wasn't sure how to make the recess in the wood so the driver is flush with the outside. I heard it is best to have the driver flush, but is it really a big difference? If I had to choose, would it be better if the driver actually stuck out a bit or was recessed into the wood a bit? I think what I will do is get another peice of wood the thickness of the needed recess and cut the bigger hole in that and laminate it to the first driver cutout peice. (Follow?). Problem with this is I'd also have to add a bit of wood to my precut top and bottom peices (to compensate for the added thickness of the front peice of MDF). For the brace, I have a peice of MDF I screwed up that I thought I would use vertically to connect the top and bottom. Generally, how should bracing be done? How much? Also, I have noise damping material similar to dynamat, should I use this on the insides of the cabinet? Finally, how much acoustic stuffing should I put in this cabinet before I close it up for good results? I think brian mentioned about 1lbs would work well. Will acoustic stuffing make my Q higher? I would like to keep it as "tight" sounding as possible. Oh, and my cube will be approx 14x14x15.
Oh one more thing - what kind of screws should I use?
I suppose this'll keep me going until I get stuck again.
Thanks!
-Junior

 

[Brian Bunge]

Junior,

There is no reason to flush mount the driver other than aesthetics. I only did it because that's what the customer wanted, and I personally like the look for a front firing subwoofer with no grill (which is how I built my dual SV12's). Using another piece of MDF to flush mount the driver is fine. That's what I did on the SV10 enclosure I built. Just cut a recess the diameter of the outside diameter of the driver and the same depth that the flange is thick. Then cut a through hole to drop the driver in. I wouldn't worry too much about the size of the top and bottom pieces. You'll just have a small seam at the top of the enclosure.

About 1 pound of stuffing should be fine. It will reduce the Qtc, which will give you a more "musical" sub. In other words, it will help to reduce response humps that might be present and give you a flatter frequency response.

If you have clamps, I wouldn't use screws at all to put the enclosure together. Just glue it and clamp it. It's a bit more time consuming, be there's less chance of screwing up the enclosure!

Brian

 

[eric]

there's less chance of screwing up the enclosure!

was that a pun?
eric

 

[Brian Bunge]

Wow! I made a "punny" and didn't even mean to! I'm so bright! That's why my father calls me Son! Not to be confused with our loveable, Patrick Sun...
(Hey it never hurts to kiss up to the moderators)

 

[Will Pomeroy]

hello, i'm kindof in the same situation.... I want to build a sealed sub with a shiva, and the final box size that i came up with was something like 2.3ft^3. I was wondering would there be any problems with this that would take away from the sound? I think i'll be using it mostly for music...

 

[Junior]

Hey Brian and others,
Thanks a lot you've all been a huge help. I guess that makes me closer to finished that I thought! I guess the only holes I need left are those for the amp and the driver. I figure the bracing should just be anything to strengthen the sides so I'll cut the mdf to size and glue it to the inside of the wood that will be on the outside. I am going to stuff it with 1lb acousta stuff from PE and put some feet on it too (spikes). As looks are not important to me, I am not painting it either, it'll be tucked away anyway, I think. Maybe in the future I will paint it up=). I think I should just buy a few tools I mean I really could use them for when I tinker with my computer as well. BTW, I hooked up the driver without a box and all looks well, just not nearly the kind of bass I want coming from this driver. Let you all know when its done and how it sounds!
-Junior

 

[Dennis Kindig]

Will,

I built an 18.5" cube using double-wall construction (15.5" internally) and after subtracting the volume of the internal bracing and the Shiva driver I ended up with about 2ft^3.

The SAF is high because it is a reasonable size and it performs very well for all types of media. I am very happy with both its punch and clarity. The biggest factor for music is how well it is integrated with the mains (setup issues). I set mine up for music, but when the LFE kicks in, look out!

I decided on a sealed enclosure because I was concerned about sacrificing transient response with music. I started out aiming for a .707 alignment as a compromise for HT, but after room gain ended up with flat response down to 25Hz and 3dB down at 22Hz.

I have wired the voice coils in parallel so I should be wringing about 300W out of the KG-5230 amp, and this leaves me enough overhead to experiment with a Linkwitz transform if I feel like disabling the amp's high-pass filter and extending the bottom end.

Dennis

 

[Anthony_Gomez]

I did a 14.5" cube a long while back with the SV-10 and the KG5150 and it was a hell of a combo! My only regrets were that I didn't get the bigger amp. the sv-10 is power hungry due to its low sensitivity. I had two of them, so the sensitivity worked out in the end for HT duty. the only reason I got rid of it was to make room (and to raise funds) for my dual BPD1503 sub
here are 3pics (with an ultra crapy digital camara) on one of them.
http://beyond_gomer.tripod.com/sub3.jpg
http://beyond_gomer.tripod.com/sub5.jpg
http://beyond_gomer.tripod.com/sub6.jpg
NOTE: You HAVE to cut and paste these links into your browser to make them work. Tripod disables any direct linking.

 

[Eric M Jones]

For what it's worth I just did a custom job for Kyle at Acoustic Visions.
I built a dedicated music sub in a 1ft^3 enclosure. It uses the 10" Dayton Titanic MKII and the Adire HS200 amp. See it here
I have to say that it's one great little performer. That Titanic driver is extremely impressive. (This is coming from a dyed in the wool Adire guy.) It even kept up with my sealed Shiva (2ft^3 enclosure) when I ran some DVD stuff. The only thing it was lacking was the very low end. But for music that's no problem.
Anyway I know you're already started on your project but I just wanted to let you know what else has been done.
-EJ