Help on 15" Tempest w/ dual PR Sub, comments, advice needed

[Mike Temple]

I am thinking of building a 15" tempest with dual PRs. The construction would be 3/4 MDF single layer with hardwood 1 x 1 stock glued at all seams and using either 2 x 2s across vert and horizontally as braces inside the cabinet as needed. (maybe 12 total)AKA Lexman on the Bracing thread Or using 2 MDF or plywood braces to opposing sides with the PRs and pieces in between facing towards the front mounted woofer, aka the Shiva white pages cabinet bracing.

First, any comments on the bracing. I know more is better but I am trying to keep the box as small as possible while still keeping it fairly rigid.

Second, I was thinking of a box around 24 x 24 x 24 for about 5.75 cu ft. after bracing and driver deductions. The box could be made smaller (gladly!!) but I wanted some opinions on the tuning point, and if this sounds viable.

A sonosub is out of the question, due to the SAF. I figure that if I build this thing, I can tell her it was a compromise and she has to accept it. I hope! LOL


Any help on modeling PRs would be greatly appreciated, As Winid doesn't use them and LSPCad (which I haven't really figued out as I have been using english measurements and the metric screws me up) doesn't either.

Thanks from the Reigning DVD Lotto Champion!!...LOL..

[ThomasW]

Hi Mike, welcome.....

PR's are something I don't do, sorry! I've only done one system using PR's, and it wasn't fun. That was many years ago, long before software based modeling was available.

So my suggestions are 2 fold. First if you are going to continue to make more boxes then just this one, buy BassBox 6 either the "Pro" version or the "lite" version. Both have excellent PR modeling capabilities. They are a pure "Windows" based programs not DOS, and are very easy to use. They are available here.

http://www.ht-audio.com/bbx.htm

Or second if this is a one time deal, then email Dan Wiggins directally. He, or AdireAudio VP, Dr. David Hyre, are always more than happy to provide very specific details as to how to use their products.

support@adireaudio.com

I wouldn't recommend using MDF pieces as cross-bracing unless it's used like shown in the links on the bracing thread. Use plywood. MDF is too soft/flexible for this task. Also I'd use 1"X2" instead of 1"X1" stock.

Regards
Thomas




theAudioWorx
Klone-Audio

[DanWiggins]

Mike,

With that internal volume, and with 5 pounds of stuffing, and twin PR-15s, I'd look at tuning to 20 Hz, via adding 335 grams to each PR.

What will you end up with? A 4th order system with a Q of 0.577, and an Fc of 20 Hz. In fact, this matches a theoretical 4th order Q=0.577 Fc=20 Hz within +/- 0.25 dB down to single digits... In other words, very good bass extension, and a nice tight sound thanks to the low Q of the overall design.

Hope this helps!

Dan Wiggins
Adire Audio

[ThomasW]

Hey, that masked man just appeared again. I wonder if he has a "faithful" companion? 8)




theAudioWorx
Klone-Audio

[Mike Temple]

WOW!

I was looking for help and what happens? Someone from the company you are doing business with helps out, without me having to contact them directly! THIS is one of the reasons why IMO Adire Audio is an incredible company. On many different boards I see posts from certain people working for companies including Adire, SVS and Stryke. I'm sure there are others but I'm not good remembering names.

No, I don't work for (hope you can tell by my newbie posts) these or any other HT company.

THESE are the companies HT lovers should continue to do business with.

These companies and other companies like Outlaw DESERVE your attention, loyalty and money for they have shown that they are true dedicated companies to both their product and to HT and music in general.

Thanks again Dan, and I will be contacting you again as I try and fine tune my project.

The reigning DVD Lotto champion (At least let me use the title for the week) LOL

[DanWiggins]

Mike,

Glad I can be of help. I try to cruise through most forums twice a week... If you are really in a hurry for an answer, feel free to drop me a note at dwiggins@adireaudio.com. I usually answer within one business day (yeah, I try not to work on the weekends...).

Dan Wiggins
Adire Audio