Print Page | Close Window

Downfiring formula, is this correct?

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=81024
Printed Date: May 16, 2025 at 4:14 AM


Topic: Downfiring formula, is this correct?

Posted By: luckydevil
Subject: Downfiring formula, is this correct?
Date Posted: July 31, 2006 at 7:38 PM

I'm using the formulas here to calculate the "Percentage of Sag."

I'm doing the calculations for an Oz Me12.4 (Fs 34Hz, Xmax 25mm).

PS = 24,849 / (25*1156)
   = 24,849 / 28,900
   = .86

Now it says... "As a general rule of thumb, any time the sag exceeds 5% of the driver's Xmax, it's not recommended for a down-firing subwoofer application."

Now am I correct in thinking that the PS should be .95 (95%) or more (closer to 100%) for the driver to be properly used in a downfiring configuration?

That last part on the Parts Express page was kind of vague.

Thanks guys.





Replies:

Posted By: austincustoms
Date Posted: July 31, 2006 at 7:57 PM
I don't get that formula, but what subs are you trying to use?



Posted By: DYohn
Date Posted: July 31, 2006 at 11:06 PM
Using that formula gets you the % sag in real numbers.  Your woofer is 0.86%, so it is a perfect candidate for up or down mounting.

-------------
Support the12volt.com



Posted By: luckydevil
Date Posted: August 01, 2006 at 12:04 AM
Good stuff. Thanks DYohn!


Print Page | Close Window