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Discussion Starter #1 (Edited)
I'm getting a pair of these subs and am not completely sure how to proceed. The way they model in WinISD, I'm thinking of going dual subs in a single ported enclosure tuned to about 12 hz. Here is the screen shot. What do you all think?

EDIT: The graph shows SPL with only 425 watts input. With two of them, I'll be able to push closer to 850w into the system which brings the SPL up to about 116 dB instead of 113 dB.
Double-EDIT: Here are the T/S parameters for those of you who would like to model them to verify my results.

T/S Parameters
Qts 0.453
Rp 5.93Ω
Qes 0.534
Dia 241mm
Qms 3.347
Vas 71.0l
Fs 24.7Hz
mms 169g
Res 7.55Ω
cms 246um/M
Ls 6.26
bl 19.2Tm
Lp 6.55
Spl 86dB
 

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I would do around 14-15 hz...
 

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Discussion Starter #4
I suppose my ultimate question is, when does extension override SPL? How deep should I be looking for?

All of the above graphs have a LPF applied at 80 Hz. That means the 16Hz tune is pretty well "flat" down to ~15Hz. The 13Hz tune has an F3 of right around 12 Hz with the 80 Hz LPF. So wouldn't that make the 13Hz tune optimum?
 

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10 cu.ft. tuned to 18 hz would be as big and low as I would go with these. They would handle 800 watts with a high pass filter at 16 hz. If pushed that hard it would take an 8 inch port 35.75 inches long. With 600 watts a 6 inch port 19 inches long would do.

Here's the WinISD file for the sub. Sd was entered as 410 cm which is about right for this kind of sub.

View attachment TC Sounds dB-500.wdr
 

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Discussion Starter #8
Why only 18Hz? (I'm not trying to question your judgment, just trying to learn.)

Also, I can't get the file to work... I'm getting an error message saying, "Not a valid WinISD save file!"
 

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Discussion Starter #10
I was using WinISD BETA (not PRO) on my laptop last night. It works fine on WinISD Pro ALPHA on my desktop at home, though. :)
 

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Discussion Starter #12

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Discussion Starter #14
I'm trying to design my box and need port volume (which I have), bracing volume (which I can calculate), and driver volume (which I need). Where/how can I find the volume that the driver takes up in the enclosure?
 

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Discussion Starter #17 (Edited)
After some modeling, figuring, adding and subtracting, I think I've got the design for my speakers together. Here is the pertinent info for those who would be willing to double-check my methods. :)

Desired enclosure volume: 11 cu ft
Volume occupied by drivers: 0.12 cu ft each
Volume occupied by port:

8" dia, 41.3" long: 2076 cu in (1.2 cu ft)


Subtotal volume 1: 11 + (0.12 * 2) + 1.2 = 12.44 cu ft

Inside Dimensions: 28x45.5x17= 21658 cu in = 12.534 cu ft

Subtotal volume 2: 12.534-1.2-0.24= 11.094 cu ft

One brace: 28x17x0.75 - 3(5 * 5) = 300.75 cu in - 40.1 cu in = 260.65 = 0.151 cu ft
Three braces total.

Total volume after drivers, port, and bracing: 10.641 cu ft.
 

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You got it close, the subs are .21 each, not .12, not that it's going to make much difference.

Port 8" dia, 41.3" long: 2076 cu in (1.2 cu ft)

subs .21 each (.42 total)

bracing 0.151 cu ft each (.45 total)

Box is 12.53 minus subs, port and bracing is 10.46 cu.ft.

The port is 41.3" + .75" for the front baffle (part of the port) = 42"

Tuning frequency will be 16.4 hz.
 
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