What specs to build by?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=48701
Printed Date: June 03, 2024 at 8:14 PM

Topic: What specs to build by?

Posted By: ippy98
Subject: What specs to build by?
Date Posted: January 27, 2005 at 1:31 AM

I am going to be building my box for my subs....

I am using the Rockford P3 DVC 4ohm subs...and on the model page of rockford for a sealed box it says the recommended volume is .65 cu. ft. and f3=35Hz ...but on the actual spec sheet the Vas is at .865 cu. ft ...and then I have tried using a few different pieces of software and most of them come up with a box of about 1.4 cu. ft. amd tune the box to about 47Hz....

which figures should i go by...and are there formulas out there for figuring it out manually without software?

Replies:

Posted By: stevdart
Date Posted: January 27, 2005 at 7:34 AM

Vas is a speaker parameter but does not refer to the recommended enclosure volume. See https://www.the12volt.com/installbay/forum_posts.asp?tid=48436&PN=4

https://www.ivhs.k12.il.us/~andrewt/veisd is a pretty useful write-up as a help file when using WinISD.

Start with https://www.diysubwoofers.org/ for math without software.

If using WinISDPro, use the help file for the recommended order of entering parameters. Change number of speakers to 2, and it will calculate one volume space and one port. For a look at how you can compare the response to the manufacturer's recommended vented volume and port size......bring your speaker up again as a new project (while leaving the current project on the screen)....enter the specs as given.......compare the graph responses as they will show on the same screen.

Posted By: ippy98
Date Posted: January 27, 2005 at 9:59 AM

ahhhh thank you...the math was what i was really looking for :)
and am i correct to say that when it says what ever volume it comes out with, that is the volume *not including* the displacement of the speaker itself? so i have to add that to the total volume?

Posted By: stevdart
Date Posted: January 27, 2005 at 6:49 PM

That is correct, as well as port displacement and any bracing you use.