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Discussion Starter · #1 ·
Guys,

I'm about to embark on a sub build and need a little help creating the driver files for the following sub. I plugged in all the info supplied from Parts Express into WinISD Pro and the app is complaining about issues with the "auto-computed" values. Can anyone help me with the missing variables or some saint :innocent: can attach a "pre-made" driver file?

I will be building (2) vented boxes -- each with (2) 12" woofs -- tuned around 20 to 25hz. I have an open attic space behind the front wall and plan to hide the boxs inside the attic. An IB setup is out because I want to control the bass into the attic space. These will be married to LCR Line Arrarys built with (12) 4" drivers and (8) Dayton Planars. Rick at Selah Audio is doing his magic with the crossovers. He suggested these drivers because they mate well with the Line Arrays I'm building.

Audiopulse EPD212 EPIC 12" DVC Subwoofer 2 Ohm
Specifications: *Power handling: 600 watts RMS

*VCdia: 2"
*Impedance: 2 ohms per coil
*Re: 3.7 ohms (series)
*Fs: 23 Hz
*SPL: 86.3 dB 1W/1m
*Magnet weight: 140 oz
*CMS: 280 uM/N
*Mms: 165 g
*BL: 14.1 Tm
*Sd: 0.050 sq. m
*Vas: 1.62 cu. ft.
*Qms: 3.90
*Qes: 0.45
*Qts: 0.40
*Xmax: 22 mm

Thanks for your help in advance.
 

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WinISD is giving grief again, so I threw it into Unibox. For a max flat 4th order alignment, 50L net/driver gives a tuning of 22Hz but to get a decently low port air speed at max power requires about a 6" Φ port, which will then be about 39' long. Sounds like a potential for external ports or passive radiators.

Graphs are for two drivers sharing an enclosure in parallel, 100L net with a single 6" Φ port at 600W/driver. If you use an external port(s) then you can easily go larger/longer.

To reduce vibration, I'd mount them in a manifold like this. the manifold does not need to be angled.



Running the drivers push pull as shown in the layout also reduces even order distortion a lot.
 

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Discussion Starter · #3 · (Edited)
A9X,

Thanks for the prompt response to my request! I never considered the 4th order design.:clap: I was planning to go with (2) direct firing in each box to keep it simple -- but do like the idea of a push/pull design. However, could direct firing be okay since these are smaller 12" drivers compared to the monster 18" Fis. :eek:

On port length, getting 39" should not be a problem if I design it right (long 6" PVC folded like you linked me to above or a well crafted slotted port may do the trickl). I can make the box long to accommodate the port.

This is what I had in mind. BUT... I am open to any suggestions. I chose to use dual ports to reduce air speed as much as possible. Given the box size and depth (probably 2'), I should be able to to get 39" without any issue.



On your 4th order design, I would think that the manifold on the box would need to be pretty wide to get the drivers installed and screwed in (assuming the box is completed and all sealed up). Is that true or am I missing something simple?

Also, any more luck with WinISD? I wanted to play around with a few designs myself and just cannot get a working driver file.:bigsmile:
 
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