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Port Location

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=64234
Printed Date: May 14, 2025 at 8:23 AM


Topic: Port Location

Posted By: Walkercustoms
Subject: Port Location
Date Posted: October 12, 2005 at 11:13 AM

Does it matter where you locate your port on your box.  I have a box with 2 12s and the ports (sloted) or on top of the box next to the divider and the subs are facing the back of the car.  If I put the port next to the sub will it make a difference.  I would not think it would since the port no matter where is still taking up the same amount of displacement.

Thanks




Replies:

Posted By: DYohn
Date Posted: October 12, 2005 at 11:32 AM
Sometimes it matters, sometimes it doesn't.  It's all about cancellations due to swound wave reflections in the vehicle (which you cannot avoid but do not want.)  Since the port is the only thing making sound at the tuning frequency, if it is oriented in a different direction than are the woofers, it will be subject to a different set of acoustic interactions.  I have seen instances where the SPL actually goes down at the tuning frequency only because of port location.  Also, you may get less bass over the entire subwoofer spectrum as the small amount of sound that escapes through the port at non-tuning frequencies may cancel part of the wave from the woofer since it will be out of phase.  The best location for SPL ports is always on the same baffle as the drivers.  But hey, give it a try and see what happens.  Be prepared to move the enclosure around quite a bit to find the "sweet spot" as it will be far more difficult to find when you're dealing with two out of phase sound waves instead of one wave.  Do you have an SPL meter?  You'll need one.

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