multiple ports

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=126898
Printed Date: May 15, 2025 at 8:41 AM

Topic: multiple ports

Posted By: pcummings32
Subject: multiple ports
Date Posted: April 09, 2011 at 3:17 PM

can anyone explain how multiple ports would work? i know i need 10.25 high x 9.5 wide x 33 long. but i dont have the room to do so. i do however have the room to do 2 ports that are 10.25 high x 9.5 wide x 16.5 long. does that work itself out to be the same as what i need?

Replies:

Posted By: DYohn
Date Posted: April 09, 2011 at 6:09 PM

No, it doesn't work that way. The only way to achieve the same tuning with a shorter port is to reduce the opening surface area significantly. To achieve the same tuning using 2 ports the same opening size, the ports would need to be twice as long.

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

Posted By: pcummings32
Date Posted: April 09, 2011 at 9:25 PM

thats kinda what i figured. that being said im told that i want 16 sq inches of port opening per cube of airspace, what are your thoughts about that? am i going lose SPL if i reduce the opening of the port?

Posted By: DYohn
Date Posted: April 09, 2011 at 9:50 PM

Yea, that's a number often tossed around and it can create decent results, but it is not a hard and fast rule. If you are going for max SPL, then you need the port to be as large as possible while still tuning to the system to the Qts that achieves the largest peak output. You need to model your woofer to figure this out and no "rule of thumb" will get you there.

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

Posted By: pcummings32
Date Posted: April 09, 2011 at 10:03 PM

thanks man. very helpful!

Print Page | Close Window