# CSS SD12 subwoofer



## Jeff Carrier (Aug 26, 2009)

Hello,

This will be my first subwoofer project. I would like to build a vented enclosure powered sub based on the CSS SD12 subwoofer. I would like to know if anyone used the double port desing found on the CSS website or the baffle-vent desing on the Solen.ca website. (I intend to use the BASH 300 amp sold by CSS)

I am not familiar with computer models for powered subwoofers and I have no idea how to enter amp caracteristics. :dizzy: Also I know that the bass boost is customizable on the Bash amps...

Anyone can :help: ???

Tanks!


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## Mike P. (Apr 6, 2007)

Hi Jeff and welcome! Is this for HT? have you decided on a box size and tuning frequency?


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## Jeff Carrier (Aug 26, 2009)

Hello Mike!

Yes this sub is for my HT. But because this is my one and only system it has to sound good for music also : I prefer quality to spl and :hsd:. The cross-over to the sub will be in the 60-80 Hz range. (My front and main speakers are DIY Audax d'Appolito array with 6.5 woofers) I have not decided on box size for the sub. The size of the CSS drawing (18*24*24 in) would be the largest size I can decently fit in my room. (taking the place of the stand under one of my main speakers, would that be a good idea??? :coocoo The size of the Solen.ca drawing (16*20*21 in) would be a little easier to fit in the room.


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## Jeff Carrier (Aug 26, 2009)

Hello again Mike!

I read the thread on your subwoofer project. I would like to know what software you used to calculate the size and tunning of your subwoofer. From the screen-shots it looks to be user-friendly. :T

Tanks!


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## Mike P. (Apr 6, 2007)

The program is WinISD Pro, there is a tutorial here:

http://www.hometheatershack.com/for...wnload-detailed-guide-how-use-winisd-pro.html

WinISD driver files can be downloaded from here:

http://www.hometheatershack.com/forums/diy-subwoofers/14410-downloadable-winisd-pro-files.html


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## Jeff Carrier (Aug 26, 2009)

Hello!

I simulated lots of box designs. Finally, I decided to work with the SDX10, because with the SD12 boxe size is to large for my room. 

Mike : I have read on another thread that you recommand a 2.5 cu ft box tuned to 21 Hz for the SDX10. I have found that using a 3 cu ft box tuned to 21 hz with a 1 db boost at 27 hz seems to pull a little more lower end. What do you think? This design is very close to Xmax at 300 W


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## Mike P. (Apr 6, 2007)

What are your room dimensions? Can the room be closed off from other areas or is the room open to other areas?


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## Jeff Carrier (Aug 26, 2009)

Hello Mike!

To room I use right now is combination living room and dinning room. It can be closed off but it is a large room. The HT area is 14 by 8 ft. The longest dimension of the room is close to 25 ft. It is an "L" shape.

By the way, if I was not renting, I would close off the HT area.

You are worried about room gain?

Tanks!


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## Mike P. (Apr 6, 2007)

> You are worried about room gain?


I was making sure the room isn't too big for the 10" sub. It works well in smaller rooms as it can't move enough air at low frequencies at high SPL for bigger rooms . Anything bigger then a 14 by 8 ft I would suggest a 12" sub.


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## Jeff Carrier (Aug 26, 2009)

Mike P. said:


> Anything bigger then a 14 by 8 ft I would suggest a 12" sub.


Very good point! :duh:

How about this : I build a 10" sub. Try it. If I am not happy with the lower end SPL, I could build a second 10" sub to go stereo subs.


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## Mike P. (Apr 6, 2007)

Good plan. Will you be porting it with round ports or a slot port?


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## Jeff Carrier (Aug 26, 2009)

With 3 cu ft, tuned to 21hz. I'am looking at a 4 inch round vent 22.3 in long. Max port speed is around 30.5 m/s. 

I am concerned by that, since port noise begins around 26 m/s I think. 

I have tried many combination of number and size of port to have a length under 24 inches. I would like to avoid having to put a bend in the port.

What would you use?


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## Mike P. (Apr 6, 2007)

A slot port would be easy to make and with enough surface area you can keep the air speed under 26 m/s.


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## Jeff Carrier (Aug 26, 2009)

Using 16.16 sq in port area, WinISD calculates a 28.9 in long port.

I was wondering... Does WinISD substract the displaced volume of the port from the total volume of the box when calculating the tunning??? Do I have to use 3 cu ft or 3 cu ft + port volume???


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## Jeff Carrier (Aug 26, 2009)

I forgot... and air port speed is down to 24 m/s!


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## Mike P. (Apr 6, 2007)

WinISD displays the net volume as seen by the sub. You have to add the displacement of the sub, port and bracing.


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## Jeff Carrier (Aug 26, 2009)

Hi!

I just received my SDX10 and Bash300. I was suprised how solid and heavy the SDX10 felt (at least for a 10 in driver.) As for the amp, I was suprised how light it was for 300 W RMS amp!!! It is the first time I work with a D class amp!!!

Is there a down side to making a bended port, like Rodny did???


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## Mike P. (Apr 6, 2007)

Not if the port has enough surface area to keep the airspeed around 26 m/s.


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