sub port screens - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 2Likes
  • 2 Post By Witchboard
 
Thread Tools
post #1 of 5 Old 06-19-2019, 06:01 AM - Thread Starter
Member
 
jim pittsburgh's Avatar
 
Join Date: Apr 2014
Posts: 21
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 10
sub port screens

I know it's an unusual question.... but I'm just finishing a build on a DIY sub with two 3" flared ports (Precision Ports). The sub will spend the summer season on an outdoor covered patio. The one thing I've not been able to find any useful information on is "what can I cover the port openings with that will prevent bugs from entering"?. Is there a particular type of screen I can buy that will not inhibit the port air movement? I've spent way too much time researching the topic and can't find an answer. Thanks for your help.
jim pittsburgh is offline  
Sponsored Links
Advertisement
 
post #2 of 5 Old 06-19-2019, 07:11 AM
AVS Forum Special Member
 
Join Date: Jan 2015
Location: United States
Posts: 2,532
Mentioned: 48 Post(s)
Tagged: 0 Thread(s)
Quoted: 1261 Post(s)
Liked: 1975
I am not an expert but--have a few things to ponder

The port size depends on the cross section area and using a screen limits the cross section so will change the tuning lower AND restrict the port flow causing chuffing and port compression. Both of those are not a good thing but I do have a few ponderings to limit that problem. I am not an expert, this is not approved by the FDA, my jibber-jabber has been known to cause cancer in California and your subwoofer might appear larger in a rear view mirror--you have been warned.

That being said, I would make a "screen box" or use the largest screen openings you can use and make a large "box" around the port(s) to get maximum screen area so to allow maximum air flow to be able to get to the poorts. For example, if you run two 3" ports which would be 3cR2X2 or 3 x 1.5x1.5 x 2 or 13.5 square inches--I'd go with a screen below the woofer but above the ports as a "box" of at least five times the surface area or larger to limit the disruption of flow. DON'T just slap a screen over the port as that reduces surface area of the port changing the tuning frequency etc.

The other option is to use passive radiators, they are a "mechanical port" or work basically like a tuning fork in operation but cost big bucks to do that. My subwoofers I built for my garage were designed to run ported in the summer and when the cold weather hits, I install plugs in the port to prevent small furry woodland creatures from setting up a winter home. Sealed in the winter and ported in the ummer works well.

The last option is to use a grill using acoustic cloth over the entire face of the subwoofer--try to keep the cloth at least an inch or two in front of the ports (or more) This might restrict the port a bit so use a very open mesh cloth if you can.

Good luck in your quest and always check the tuning of the box after you build either a screen box internal or external to ensure the proper operation of the port.
18Hurts is online now  
post #3 of 5 Old 06-19-2019, 09:35 AM
Member
 
buggers's Avatar
 
Join Date: Dec 2006
Posts: 188
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 18
Ladies pantyhose works excellently!
buggers is offline  
Sponsored Links
Advertisement
 
post #4 of 5 Old 06-19-2019, 12:55 PM
Senior Member
 
Witchboard's Avatar
 
Join Date: Oct 2008
Location: Oklahoma City
Posts: 490
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 183 Post(s)
Liked: 167
Quote:
Originally Posted by buggers View Post
Ladies pantyhose works excellently!
Agreed.

Witchboard is offline  
post #5 of 5 Old 06-19-2019, 02:32 PM
Member
 
BlueGhost's Avatar
 
Join Date: Feb 2018
Location: Houston, TX
Posts: 59
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
Liked: 17
Quote:
Originally Posted by buggers View Post
Ladies pantyhose works excellently!
It may even fit between the joints in a precision port.
BlueGhost is offline  
Sponsored Links
Advertisement
 
Reply DIY Speakers and Subs

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off