Help Me Build My TEMPEST :) (1 Viewer)

[Chris Carswell]

Hey Guys,
Because of YOU fellow posters, I finally decided to do it and got myself a PE amp and Tempest. I was originally going with a 300 L box tuned to 19.5 HZ but it was a little big for my room. I have been told that if I keep it ~ 210L (7.25 cu ft) I should be OK. So I will. I am going with a Chris Tsutsui type Frustum Pyramid design. I will finish it in High Gloss Piano Black (P.I.T.A. but well worth it).
Brian already helped me out a lot but I had a few more ???
1. Adire's site said to have it at 7cu ft tuned to 20hz with 2 4" ports 16.5" long. When I run Win ISD I come up with 1 4" port at 9" or 2 4" ports at 21" Which do I go with?
2. Brian said to use some Dacron Batting on the inside but I can't get any. Should I line it with insulation or polly fill & if so how much?
Any other tips I should be aware of, please LMK. I plan to put it up on the web like what Pat does but it won't be that well documented. Thanks again.
Chris

 

[Isaac C]

1. Adire's site said to have it at 7cu ft tuned to 20hz with 2 4" ports 16.5" long. When I run Win ISD I come up with 1 4" port at 9" or 2 4" ports at 21" Which do I go with?

I believe Adire meant 4" flared ports. winISD calculates cylindrical ports, which would explain the difference in port length.
Polyfill will do. Remember to secure it properly and at least a port diameter away from the port(s).
Cheers
Isaac

 

[Brian Bunge]

Chris,

I'm confused about #2. You're in FL and I know there's probably half a million Wal-Marts and fabric stores down there. The Dacron batting is simply the material they use for comforters. It's basically poly fill in sheet form. You could simply use spray adhesive on the inside of the enclosure and stick it on.

Brian

 

[Chris Carswell]

:b
Brian, I had no idea that's what that stuff is. I wasn't sure what it was so when I called my local hifi shop and another car audio place they must have confused it with "Dyna Matting" ( Dacron batting, close enough ). They both said they never heard of it but said they would sell me some Dyna Matt, which they said was probably better anyway. What an answer, "We don't have it but the stuff we do have, Dyna-Matt, is better so come in and buy it" I didn't know any better but I wasn't going to pay that much to line my sub with dyna matt. Now I know. Thanks guys for the tips.

 

[Bryan Michael]

how much polly fill should you use with a 200l encloser? and what happens if you dont atach it that good? and y do you keep it awayfrom the ports?

 

[Chris Carswell]

Bryan M, that's a good question. I was thinking the same thing b/c my net volume is ~200. How much polly fill do I need to use? Do I just line the thing or is more of a stuff????

 

[Brian Bunge]

The purpose of stuffing an enclosure is to get more apparent volume from a smaller enclosure. In other words, if you have space constraints and 200L is as large as you can go, but you want to mimic the response of say a 214L enclosure, you'd use some stuffing to increase the apparent volume that the driver "sees".

If the sims you've run are for a 200L enclosure and you're happy with those sims then simply line the walls of the enclosure.

Brian

 

[Chris Carswell]

Thanks again Brian
now to cut some MDF..............MUHAHAHAHA!!!!
-Chris