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Discussion Starter #1 (Edited)
I have an Elemental Designs 13Av.2 dual-2 driver just gathering dust in the storage for about a year now.
After some tinkering with WinIsd, I decided to finally make a box for it. Next week I will get the other piece from my friend to make a dual driver sub.
My plan is to make a box that has 7 cubic feet internal volume tuned to about 20Hz.
Initial modeling with WinIsd says its response is +/-0.5dB from 20Hz to 80hz. f3 is about 18Hz.
I don't want a box larger than 8 Cu internal since it will be very heavy. Im losing a lot of headroom at 20-40hz when I use larger box and tuning it lower than 20Hz.
The use of the sub would be 60/40 for HT/music.
The choice of using dual driver is to have a good headroom, lower extension, and building it will usually need less work than building 2 subs each with 1 driver.

Do you think this is already good?

Box design using Sketchup:



 

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Discussion Starter #2 (Edited)
Pics of the finished sub, sorry for the blurry pic, these was taken using a cellphone cam:


Larger pic: Right Side


Larger pic: Left Side


Making of the Grill


With grills on

Finish comparison with my MA RS1 fronts:



I was not able to take some pics of the internal bracing during the making, I was always excited I forgot it.
The box was well made and the bracing is almost a mirror of the drawing.

Spoiler
I still have more drivers here, a JL Adio 12W7 and two pieces Infinity kappa 12dvq. I will use 5Cu for the JL and will be used for my PC setup, while the dual kappa will built in dual-opposing driver config ala submersive and will be used for my music-only setup. Next time I'll build the boxes myself.
 

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I think it will work well. That is about where I was at with my Pulse build.

Is that about an 8" diameter port at about 38-40" long... or are doing a slot port?

Make sure you take lots of pics.
 

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Discussion Starter #6
I have a friend who is an Electronics Engineering graduate and he specializes in making subwoofer amps.
I commissioned him to make an amp for me. 4 pcs of amp each giving 600 Watts @ 2 Ohm. The drivers are dual voice coils so each voice coil is powered by a single amp.

BTW, is it good to use ordinary plywood for the bracing?
Im thinking of using 3/4" plywood for the bracing because I though it is stiffer and lighter than MDF.
 

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Discussion Starter #11 (Edited)
I still have a few questions before proceeding with my box build:

1. Would lining the internal panels of box with Dynamat help in reducing vibrations? Or it's just waste of money?
2. Is it safe to break-in the sub in free-air?
I tried playing the sub in free-air at low volume and it sounds fine. But when I push it in the moderate volume, it's already making some annoying noise.
3. The motor of the driver seems to be making an audible noise. Will lining the box with 2" 80Kg density rockwool help in reducing the noise generated by the driver's motor? Or is it bad because it will just reduce the output?

4. Would it be better to just place the 2 drivers opposing each other with the cones facing outside and the magnets inside? Isn't it called isobaric configuration when placed like this? Someone told me that dual opposing drivers cuts the internal vibrations greatly but Im worried if this has the same effect as isobaric configuration such that the efficiency and output is also greatly reduced.
 

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!. No idea on the Dynamat. I've always used egg crate foam to line the walls of a ported sub.

2. Yes. just don't get carried away with excessive excursion.

3. Once the sub is mounted in the cabinet motor noise shouldn't be an issue.

4. Yes, opposing drivers cuts the internal vibrations, but if you have a well braced cabinet having 2 front firing subs would sound the same and have the same output.
 

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Discussion Starter #14 (Edited)
My sub is finished at last. I was able to find a shop which built the box for me.
My goals was more or less achieved. The output is amazing especially at low frequencies and I like the glossy rosewood finish, almost near my MA RS1 fronts. Drawback is that it's big and very heavy at more than 200 lbs. Another drawback is that, since the result was good, Im now addicted to DIY subs, now I have more drivers waiting on the pipeline.
 

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Nice build. Not too many people use the 13av2's. How was the motor noise once the system was finished? Inaudible now?
 
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