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Discussion Starter #1
Ok, so I'm in the process of finishing off my basement and I am going to place 2 JL 13w7 at the front as sort of a large stage below the screen. I can go roughly 68" wide for each and that will fill out the width of the room. I had figured about 20" tall (20" is the maximum) and 24" deep with ~70" long 4"x16" port. I plugged it into WinISD, and it looked ok to me but to be honest I don't know enough about it to know for certain. Each sub will be getting approximately 1000-1200W each powered from a Crown XS1200 amplifier.

Any input on the size and tuning for the port is appreciated, I can really only go 20" tall and 68" wide are the max dimensions the depth could be anything really. I already have the amp and both subs, actually been running one sub in a smaller 30" cube box and it is amazing.
 

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The drivers and amp sound like a good build.

I'd be worried about the 68" enclosure dimension and the 70" port length. These could both place resonances down close to the upper bass range of your subs and additionally they would both have a resonance very close to each other which may reinforce each other making the problem even worse. I'd try to do something to atleast cut the port length down or separate the 2 dimensions so that they don't reinforce each other.
 

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Discussion Starter #3
I'll take a look at that, I was worried that it may be getting to large.

I guess I should have mentioned that I am open to any other size suggestions, this is just what I came up with for simulating a large stage. If there is an "ideal" size that would fit the same area I am all ears, just want to get it right the first time.
 

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Discussion Starter #5
Honestly, I'm not sure which version I have. I have since thrown out all of my paper work. Were there multiple versions, I was using the standard model in WinISD.
 

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Discussion Starter #7
I was just checking to see if there were different versions. How old are the subs you have?
They are right at or just under 1 year old, one of them is installed in a temporary box to try it out and the other is still in the shipment box awaiting to be installed. The JL 13w7 is the newest model and I don't believe they have been out long enough to get an updated version.
 

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I checked and the specs are the same for older and newer models, but the WinISD file is for the coils in parallel. I imagine you'll be running the subs with the coils in series?

This is modeling of series wiring. 10 cu.ft tuned to 17 hz with a slot port 4" x 12" x 39" long. With 1000 watts input a high pass filter would be needed at 14 hz to stop the sub from bottoming out at 15 hz and lower. Maximum port air speed would be 24 m/s at 16 hz.

13 w7.JPG
 

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Discussion Starter #9
Ahh yes, I did not realize that it had the coils in parallel and you are correct that they would be run in series. Is there any advantage to increasing the volume of the enclosure? This lower volume might allow me to place my paradigm signature C5 in between the two subs and mount the screen a bit lower to allow for a tre ceiling.

I checked and the specs are the same for older and newer models, but the WinISD file is for the coils in parallel. I imagine you'll be running the subs with the coils in series?

This is modeling of series wiring. 10 cu.ft tuned to 17 hz with a slot port 4" x 12" x 39" long. With 1000 watts input a high pass filter would be needed at 14 hz to stop the sub from bottoming out at 15 hz and lower. Maximum port air speed would be 24 m/s at 16 hz.

View attachment 15356
 

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Discussion Starter #11
Thanks Mike your input is greatly appreciated. BTW how were you able to modify the driver model, it kept erroring out on me and wouldn't save it when I tried to change it from parallel to series.

Also what high pass filter would you recommend?

10 cu.ft. net volume would be as big as I'd go with them. Any bigger and you aren't gaining much.
 

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Discussion Starter #12
Mike, how would a sealed enclosure work for these subs, I saw another setup where someone had done something similar to mine with 4 ft^3 sealed boxes. I always read that the w7's were better with a ported system, figured I would ask the question out of curiousity.
 

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The easiest way to change the parameters is open a project with the driver first then edit the parameters. Change the Re from 0.602 to 2.4 and change the BL from 7.48792 to 14.975

A rule of thumb is it takes 2 sealed subs to equal the output of one ported sub, using the same driver.

CSS sells the Reckhorn HPF's, the B1 is good down to 15 hz and the B2 is good down to 12 hz.

Here you can see the advantage of the ported over the sealed, the ported has greater output at 20 hz by 8+ db, and 11+ db at 17 hz.

JL 13 w7.JPG
 

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Discussion Starter #15
The easiest way to change the parameters is open a project with the driver first then edit the parameters. Change the Re from 0.602 to 2.4 and change the BL from 7.48792 to 14.975

A rule of thumb is it takes 2 sealed subs to equal the output of one ported sub, using the same driver.

CSS sells the Reckhorn HPF's, the B1 is good down to 15 hz and the B2 is good down to 12 hz.

Here you can see the advantage of the ported over the sealed, the ported has greater output at 20 hz by 8+ db, and 11+ db at 17 hz.

View attachment 15360
Wow, well ported it is then. Mike you have been a huge help on helping me make my final decision. Now I just need to figure out my final dimensions, I can't wait to hear two of these in my new room.
 

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Discussion Starter #17
I'll definitely do my best, i'm in the middle of finishing the actual theater as well as all these small projects like the sub boxes and star ceiling, etc so I hope to get pics of all the projects.
 

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Discussion Starter #18
Few more questions, when you take out the volume for the box port when calculating the total volume of the enclosure. Do you include just the dimensions of the wood itself, or the wood as well as the air space it encloses?

Also any recommendations on the high pass filter?
 
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