# cabinet question

Discussion in 'Home Theater Projects' started by Alex_P, Jan 19, 2004.

1. ### Alex_P Stunt Coordinator

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Using WinISD, I choose closed cabinet. The measurement comes out to be 20.9"W x 32.4"H x 13.1"D. I don't like the shape of the box. I want to make it like a perfect cube box. With a lil math calculation, for a perfect cube box the length of each size is approximately 20.8" (doing it by hand, perhaps I should use a calculator ).

Questions:
1. Will a perfect cube box has the same result as the retangular shape (assuming they have the same volume)?
2. I want the driver to fire downward. Does it matter if the driver fire front or down since it's a closed cabinet?

This sub is going to be 90% movies and 10% music. I want to get a flat response on SPL. I wanted to go with ported cabinet BUT the size of the cabinet is too big So I decided to go w/ the closed cabinet. Can someone give me some inputs regarding my 2 questions above? Thanks a million...

Alex,

2. ### Patrick Sun Moderator Moderator

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1. Yes.
2. Probably not, but you can easily test by orienting the cube either way and listen to what sounds best to you.

3. ### Dave Milne Supporting Actor

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A cube should be fine. Most speaker deisgn software defaults to a rectangular shape to minimize coloration from standing waves. At sub frequencies, though, that's not generally a problem since 1/2 wavelength of 80Hz is over seven feet!

Downfiring is generally OK, but you'll lose a tiny bit of excursion from cone sag. Different drivers suffer from this more than others. I believe Adire's website has a little forumula to calculate the excursion loss based on Vas, Mms, etc.

Ah yes... a common problem. Do you still get an acceptable F3? You may want to consider a Linkwitz Transform circuit to recover that lowest 1/2 octave.

4. ### Alex_P Stunt Coordinator

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Thanks Patrick and Dave...

I have more question
It seemed like the version of my WinISD has an error or something. I changed the box size but it didn't seemed like on Plot Window has anything changed. Can someone help me w/ the software? I pretty much decide to get Shiva Mark IV driver w/ 250W amp (unless there's a better driver for the same \$\$\$). If it's possible can someone help me come up w/ a cabinet size. Since I can't get WinISD to work properly. I want to have a perfect cube box, closed cabinet. Thanks a lot...

Alex,

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