# Enclosure design help



## LMN8R (May 19, 2009)

Long time lurker first time poster. I recently aquired 2 CSS SD12 drivers that I would like to build an enclosure for. I'm not looking for max spl as much as capable of low freqeuencies. I would like to keep it around 8 cubic foot internal, ported for a 15 hz or lower tune. I have downloaded WinISD pro but am not comfortable enough with my skills with it to try and design a dual driver ported cabinet. I've searched and can't seem to find what I'm looking for in a tried and true design. Any help would be greatly appreciated.


----------



## Mike P. (Apr 6, 2007)

Welcome to the Shack Dave! What will you be using to power the sub?


----------



## LMN8R (May 19, 2009)

Thanks for the welcome. I'll be using an external pro amp. I currently have a Behringer A500 that I will be using until I get a couple of other things upgraded. I'll most likely be purchasing the ED sub eq with HPF as well. I know I'll be needing the high pass filter in a ported design, I'm just not 100% sure yet what I'll be using. I plan to get a more powerful Behringer in the future to get the most I can out of the SD12's


----------



## Mike P. (Apr 6, 2007)

Then let's plan for the power in the future.

SPL would be 110 db at 15 hz, plus room gain. Cone excursion is reached with 1000 watts input power and a high pass filter at 14 hz. A 6 inch diameter port needs to be 37.75 inches long to tune the cabinet to 15 hz, add an inch to the length if going with a flared port. Port air speed is under 26 m/s at 14 hz.


----------



## LMN8R (May 19, 2009)

To verify, is that both drivers in 1 enclosure.
Thanks a bunch for the help


----------



## Mike P. (Apr 6, 2007)

Yes, 2 subs in 8 cu.ft. 500 watts to each sub at 4 ohms.


----------



## LMN8R (May 19, 2009)

Thanks again


----------



## Mike P. (Apr 6, 2007)

Will you be posting a build thread?


----------



## LMN8R (May 19, 2009)

I can do that. I enjoy all the build threads so I might as well add to them. I've got them up and running in seperate enclosures that I already had. 1 sealed and 1 ported run in series with a jumper between the two. So far I'm really impressed with the SD12's but I know they can sound better. I picked them up on e-bay for $154 delivered for the pair. New and never used, couldn't pass them up for that.


----------



## Mike P. (Apr 6, 2007)

> I picked them up on e-bay for $154 delivered for the pair.


Wow, you got a deal! Looking forward to your build.


----------



## LMN8R (May 19, 2009)

This project has been on hold for a while. We've been busy building our house. We are about to get the LR done and I'm about ready to get this project started. I plan to use a slot port 3 inches high. What would be the optimal width/length for the port for the 15 hz tune. Enclosure will be 8³ net with 3/4 MDF.


----------



## Mike P. (Apr 6, 2007)

The easiest way to make a slot port is use the full width of the box. Let me know what your box dimensions are and I can figure out the best height and length of the port.


----------



## LMN8R (May 19, 2009)

My wife has decided she would rather have two smaller enclosures versus one bigger one. I'm looking at building the cabinets 19.5 X 16 X 32 inches high. Shes OK with that (and so am I). This should net about 4 cubic feet. Slot port should be 18 inches wide. Unless I'm doing something wrong in WinIsd it appears the air speed is too high with a reasonable length port configuration. Any help would be appreciated.


----------



## Mike P. (Apr 6, 2007)

1.5" x 18" x 41" would tune 4 cu.ft. to 20 hz. The sub would take 700 watts with a hi-pass filter at 18 hz. Air speed is under 20 m/s.


----------



## LMN8R (May 19, 2009)

Thanks Mike. I figured I must be doing something wrong.


----------



## LMN8R (May 19, 2009)

The cabinet is built! Unfortunately the batteries were dead in my camera. I'll post some pictures of built cabinet and the finishing when I get to that.
I bought the SD12's used and they appear to be dual voice coil. I received no information when I bought them and they are no longer on the CSS web site as they have been discontinued. Does anyone know the impedance of the voice coils?
I can't wait to hear these. They are built like tanks.


----------



## Mike P. (Apr 6, 2007)

I forget if it's dual 2 ohm or dual 8 ohm, Bob will be here shortly to answer that. FYI here's the info on the sub:

http://www.creativesound.ca/pdf/CSS-SD12-subduction-data.pdf


----------



## LMN8R (May 19, 2009)

Thanks for the link.
I had a print of that but couldn't find what I needed.
Thanks for all the help Mike it is truly appreciated.


----------



## Creative Sound (Mar 29, 2007)

LMN8R said:


> The cabinet is built! Unfortunately the batteries were dead in my camera. I'll post some pictures of built cabinet and the finishing when I get to that.
> I bought the SD12's used and they appear to be dual voice coil. I received no information when I bought them and they are no longer on the CSS web site as they have been discontinued. Does anyone know the impedance of the voice coils?
> I can't wait to hear these. They are built like tanks.


Hi,

Not sure what you have but they were single 4 ohm voice coils.

Bob


----------



## Mike P. (Apr 6, 2007)

> Thanks for all the help Mike it is truly appreciated.


Not a problem, and I forgive you for the dead batteries! :bigsmile:


----------



## LMN8R (May 19, 2009)

It wouldn't normally be a problem but I had help with the 3/4 MDF on the table saw, we got on a roll and finished roughing it in in 1 day. I didn't want to pass on the help while I made a trip to town.


----------



## LMN8R (May 19, 2009)

Creative Sound said:


> Hi,
> 
> Not sure what you have but they were single 4 ohm voice coils.
> 
> Bob


OK now I am confused.
They have two sets of connectors 1 on each side.
I didn't buy them directly from you but they have a CSS SD12 label.


----------



## Mike P. (Apr 6, 2007)

Here's a pic of a SD12 from another build. Is this the same as what you have?


----------



## LMN8R (May 19, 2009)

That's the one (or two actually). Even on the link you sent there appears to be two sets of connectors on the sketch. I'll look closer when I get home maybe one is not used.


----------



## Mike P. (Apr 6, 2007)

What did you find out?


----------



## LMN8R (May 19, 2009)

I haven't pulled the driver back out of the cabinet yet. When I wired them I paralleled the windings. I checked with an ohm meter at the connections at the back of the cabinet and read 3.6 ohms so I'm assuming 4 ohm Z total. I had some minor surgery this morning and I'm not supposed to lift any thing for a week so for the time being I just have to enjoy them as they are. They sound awesome! I picked up some 3/4 inch oak plywood to cover the mdf on the fronts of the cabinets and 1/4 inch for the sides and tops. I'll post some pics when I get started on finishing them. For now I get to spend a week enjoying the HT gear while I recuperate. Thanks again for all the help, I'm sure they wouldn't sound as good as they do without it.


----------



## Mike P. (Apr 6, 2007)

Heal up and enjoy your sub. Post whenever your ready. :T


----------

