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This weekend I'll be returning to my home town for some weeks during the holidays. This is the time I will build the two beasts I've been dreaming about for 6 months... They are going to be ported designs. The material chosen is 3/4" MDF. Inner measurements are WxHxD 19.68x51.18x15.74. There will be two braces in the box, approx 19.68x15x74 with a 17.3x13.4 rectangle cut out, each brace should displace about 0.96 litres.

The port will be a rectangular one as I don't know where to get 6 or 8 inch ports here, importing is expensive... Inner measurements of the port (millimeters): 400x40x615 (or 15.74x1.57x24.2 inches). I was planning on running the port along the side of the box. I don't think (but I'm not sure) that the air speed will be a problem, at 650 watts input. ca 20m/s @ 12.5Hz and 14m/s @ 21Hz. If I could use Google Sketchup or something I'd given you some nice pictures.

The internal box volume, including braces, driver and the port lands at 236.3 litres, tuned to 17.77Hz.

It will be a double baffle as well, so the driver is mounted "flush" to the baffle, gives it a cleaner look. What I'll probably do is complete the box, then just glue the outer baffle onto the front of the box.

PDF with graphs, etc: http://www.2shared.com/file/4477811/bceede4/Tempest-X-vented-box.html

T/S parameters of the Tempest-X: http://www.subwoofer-builder.com/driver-exodus-tempest-x.htm

Bassbox Pro design file: http://www.2shared.com/file/4477913/e402e6ff/Tempest-X_240L_slotport_F3_195Hz.html

So I guess my question is, do you see any showstoppers? Or should I just get to it?

Regards,

Mathias

 

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Using WinISD, port air speed with 600 watts input would be 21 m/s at 20 hz, 29 m/s at 15 hz and peaks at 33 m/s at 11 hz. The port dimensions are wide and narrow, not the best for air flow. Changing the dimensions to 3" by 9" by 27" long would be a better choice. It will help with air flow and has a slightly larger surface area to reduce air speed.

Yeah I kinda had an itch saying that the port would be a problem in this respect. However, inputting your parameters into bassbox shows only 1m/s difference on most frequency, strange. I thought I'd do the port as wide as the depth of the box for simplicity.

Well, it just means a bit more cutting and planning. Thanks for the input!

 

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I went with sealed. All the pictures can be found at this url: http://www.minhembio.com/fackamato/222602/

Nevermind the comments.

All in all I'm very pleased, but I haven't had a chance to stress them yet... can't wait to put some metal on!

 

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~210 litres or a bit over 7.3 cubic feet.

Merry xmas btw!

 

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Yes you have, Håkan . I added some extra bracing and started to paint. Here's the pictures: http://www.minhembio.com/fackamato

 

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I've now added the second (and final) layer of paint today, later tonight I'll hopefully assemble the speakers, the paint takes its hours to dry...

A picture of the first coating:

 

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Now they're finished. I switched to t-nuts. T-nuts owns! (almost) hassle free.

 

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Looks good :T

Do you have reflection problems from center speaker??? ... (I think is to far back, subs are in front of speaker) :huh:

Thanks the room is a mess (well the whole apartment is), because of various things (renovating etc...)

Don't know about any reflection problems, I haven't watched any movie yet.