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Discussion Starter · #1 · (Edited)
I recently found a sub that provides me with that desirable for me low FR curve with serious amounts of power :ponder: and all that promised with small enclosure. The elemental designs eD 13Av.2 :bigsmile::T. Happy i finally got it. And couldnt help but modeled it with BassBox right away.

With somewhat iterative process i came about 80 liters(2.85cu ft) eclosure. That giving me the awesome optimistic for me F3 of 17Hz (precisely 16.9Hz) with 2x AE PR15-1400 PRs with added 250g more weight. I played with it untill i got what i want.


And here are the results:

The FR:





Here are the AE PR15-1400 PR specs i entered:





I wanted to proove those results and i get my heands wet with the WinISD :sn:. I managed to find my way around and the program corrected some parameters. And with the same driver and PR specs i get completely different results -> F3=28.4Hz, here:




What is more, with WinISD i get that low F3 freq of 17Hz but with 5times lower PR weight - 300grams :huh:.
And here i am, wondering which program should trust, and where should i go to? With ported box design the results are the same for both programs though (a Hertz or 1.5 Hertz at most difference).
I need help from you guys, anyone with WinISD or BassBox hands on is also welcomed.

Veltinorian
 

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Are you sure on those parameters

Thiele Small parameters:
Fs (Hz) 4.25
Qms 60
VAS (ltrs) 978
Mms (g) 1400
Cms (mm/N) 1.0
Sd (cm²) 830
Xmax (in) 2" p-p

is what I get for your PR's from AE

It appears you have something different between the boxes. Could it be fill on Bass Box?
 

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Discussion Starter · #3 · (Edited)
Thanx, Isiberian, fs and Mms are here different from those in the pdf specs due to the mass of 250grams i added. With the added mass i got those better results with BassBox, the low F3 frequency. But those inputs are the same for both modeling programs.
 

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WinISD and BassBox use different figures for box losses (Ql) and stuffing effects, and have some different assumptions inherent in the calculations. Though it has been a while since I used it last, BassBox refers to this as the "BassBox box model" if I recall correctly.

Depending on who you ask, you will get different answers as to who is right. For what it is worth, I've had pretty good correlation with BassBox's predictions, but that is just my experience.
 

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Discussion Starter · #6 ·
When you created the driver file for WinISD did you enter the parameters using the "auto complete" feature?

If you refer to the check box "Auto calculate unknowns" at the "Parameters" tab from the Driver editor, yeah Mike i did it so :huh:, it complained a bit but after i deleted only the Qms and Sd parameters and WinISD calculated those for me in blue and saved it successfully as a driver :blink:.
 

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Discussion Starter · #8 · (Edited)
Thanx Mike, here you are:


Also with the slightly changed values for Qms and Sd i did the model in the BassBox, actually it doesnt change anything in comparison. But the difference between WinISD and BassBox (for PRadiator box design only) is compl uplausible for me.
 

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Discussion Starter · #10 · (Edited)
Thank you, i modeled it with your driver. Only the slope angle changed very little but the F3 frequency is the same, same results :huh:.

In the meantime if you recall the Mike Cason's 2100 grams 4xPR project and i am close to those results with BassBox, i mean BassBox favours the heavier PRs..
Which math is more realistic so i can go that way?
 
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