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Discussion Starter #1 (Edited)
Hi,
I have been reading on the board alot, and thought i'd give my first post a shot :jiggy:

I'm a huge fan of DIY so I thought i'd build my own sub. I thought id ask as much questions first before I order so i can make the right choices.

Lets start with some specs:
I have a small living room ( 15'x14'x 8'tall ) its open to the kitchen. Other areas are all closed with doors.

I plan on using the sub every day and for everything ( music, videogames, movies )

I have been researching on the best materials I could use and it seems that its either HDF or stone.
I do have access to fairly cheap granite and thought I'd give it a try. I am used to cutting stone as well as glass with diamond bits submerged under water.

so, my current plans are for a single 12" sub, on a closed/sealed box measuring 18x18x18" exterior dimensions using 1" thick granite. I would seal it with the proper silicone to make it completely air tight.
and add bracing inside of course.

a few questions:
Would you recommend I stay away from granite ? if so why ?

Would you change the size of the enclosure ?

I have been researching amps, and found this one which seemed descent.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-808
I would set it up outside in its own enclosure.

The drivers i'm looking at are the peerless 830500 and the NHT 1259..
peerless:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=297-608


nht 1259 is on ebay..
http://cgi.ebay.ca/NHT-1259-12-Woofer-PAIR-NIB-NR-L-K_W0QQitemZ220307271420QQcmdZViewItem?hash=item220307271420&_trksid=p3286.c0.m14&_trkparms=66:2|65:3|39:1|240:1318

I have a bit of skepticism with a sub worth 25$.. LOL

I need suggestions for subwoofers, what would you put in there to get the clearest nicest results. I'd love to reach a clean 20hz

I am trying to accomplish a smooth deep bass, doesn't have to rip out windows.. more into quality over quantity.

budjet: ~1k..( for driver and amp ) but opened to suggestions :)


Cheers !!
 

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Discussion Starter #2
I could not post a link for the amp since i'm new here.
Here are the specs:

* High power Class AB output stage
* Patented tracking down converter power supply
* Full parametric bass EQ
* Phase reversal switch
* Auto On/Off
* Advanced soft clip circuitry
* Toroidal power supply transformer
* Power output: 512 watts RMS 8 ohms, 1024 watts RMS 4 ohms
* S/N ratio: 98 dB (A-weighted)
* Low-pass crossover: 30 - 200 Hz, 24 dB/octave
* Auto On/Off
* Dimensions: 11-15/16" W x 11-15/16" H x 5-1/4" D
 

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You will be disappointed with the low end output of the 830500 in a sealed enclosure for HT use. It would work better in a small enclosure with a passive radiator. It will produce about 104 dB with 300 W RMS at 25 Hz. It is also a 8 ohm sub.

http://tymphany.com/xls-12-subwoofer

The NHT 1259 would need a larger cabinet then the 2 cu.ft. box you describe. It should be 3.5 to 5 cubic feet. Even then it will take an amplifier with low frequency boost to get down to 25 hz.

http://www.madisound.com/catalog/product_info.php?products_id=1402
 

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Discussion Starter #7 (Edited)
he he.. i hear ya.
how about 2'x2'x2' which would be 6cf - bracing.

how about the JL 12w7-3 ? or the 12w6 ?

been using the winISD pro.. and trying different setups.. the 12w6 needs 3.7cf not too bad.
 

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Elite Shackster
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For a $1000 for amp and driver you can do really well. As a quick suggestion you may look at the DIY Shiva, it's one of the best 12" drivers out there right now. Are you set on a 12" driver? With a 2' cubed enclosure you could easily put 2 of the shivas in or a bigger driver. 2 15's or 1 18 would not be out of the question.

I'm not familiar with cutting granite but I bet it would work great as a subwoofer box. Talk about damped! How easy is it to cut circular holes?
 

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I would be very interested in a build useing granite, sound interesting just as long as you don't have to move it too much. Keep us informed with info and pics, and welcome to the forum...:yay:
 

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Wow LiV,
A granite enclosure . . . . . . really!!?? If you can do that you'll want to upgrade your driver choices to include the 18" drivers from Exodus Audio (Maelstrom X), Mach 5 Audio, Sounsplinter, F I Audio, and CSS for your 12" and 15" drivers. Then add a Behringer EP2500 amp to go along with it. Wouldn't it be extraordinary to have the best most inert enclosure loaded with one of the worlds best and biggest drivers!!?? What a show piece THAT would be.
LiV I encourage you to make your own choices however, and take this project through to completion right here in front of all of us.
 

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Discussion Starter #12
he he.. thanks for all the replies..
After reading the posts about the maelstrom X .. i'll be doing exactly that I think.. and will get my hands on a ep2500 also.

I will post some pics when I start ordering the parts and assemble them.
as for cutting a round circle, I've never done it.. I did cut quite alot of glass and rock but either it was drilled or was a straight line.. I will ask the local shops to do the cuts and have them rounded for me.

Cheers,
LiV,
 

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Discussion Starter #14
I do have one trouble at the moment.. i'm trying to figure out how I would attach the sub to the granite I'm worried the holes i would drill too close to the edge would just snap off.. so I'm thinking getting the granite cut larger.. so the sub woulnd't touch it.. and then add 1-1/2" of hdf glued to that granite so I may attach the sub..

also, looking around the thickness of granite, I have either 3/4" or 1-1/4.. i'm leaning towards the 1-1/4.. but afraid i'll have to build the sub where its going to rest as it may weigh too much to carry around.


any thoughts on the clamping and material thickness ?
 

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and then add 1-1/2" of hdf glued to that granite so I may attach the sub..
If you were to glue a HDF mounting ring on the inside, you could use T-nuts and bolts to mount the sub. As for material thickness, I would think 3/4" granite would be fine. What type of joint will you use on the cabinet corners, a bevel joint or some other type?
 

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Discussion Starter #16
thats exactly what i'm thinking.. a mounting ring on the inside, attach sub to it.. glue ring to granite with a large contact surface so no chance it can get detach.

as for the joints, most likely all flat with the exterior edges rounded with a 1/4" or 1/2" round.

Been plotting a few graphs with the subs specs and box parameters.
I dont loose much db if I lower its size to ~4cu ( from a 24x24x24 to 22x22x22 ) like ~1.02db at 20.01hz. thats with heavy damping and an interior brace in the middle.
 

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If you use a 6 cubic foot sealed box I'd make plans to buy an EQ also. The Behringer will work and give you the flexibility of EQing the bottom-end to achieve whatever LF curve you desire. The Maelstrom works great sealed but you give up some bandwidth compared to the PR or ported versions.

My recommendation for sealed Maelstroms is at least 6-10 cubic feet. If you build on the smaller side of that scale you are giving up bandwidth. You can considerable extension by going with a PR build.

Kevin Haskins
Exodus Audio
www.diycable.com
 

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Discussion Starter #20
he he.. ya.. been thinking quite a bit about this lately ;)
for the EQ, do you have one to recommend ?

for the bracing, I figure its going to help me to assemble the box and make things square.. and why not keep it.. can't hurt.

also, where's the best place to purchase the woofer ?
 
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