Sub Box
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=1877
Printed Date: September 17, 2025 at 6:15 AM
Topic: Sub Box
Posted By: sparkyssb
Subject: Sub Box
Date Posted: July 11, 2002 at 6:06 PM
Hey. I have had a sub in a box that my brother made for awhile. We made a small box for a 10" sub to fit in my truck. It is roughly 12.2 x 12.2 x 6.5 or so.....the wood is pretty thin (maybe .25")... well, before you start yelling at me for the small box  , I would like to know if I would get 'more bang' if I were to port it. It is currently sealed. (I listen to rap and hip hop)
Thanks guys.
Replies:
Posted By: GlassWolf
Date Posted: July 11, 2002 at 7:47 PM
In order to port the box you need the Thiele-Small specs on that speaker to get the exact port length and inner diameter needed to tune the port to a give frequency (usually 30 to 45Hz)
Yes a port would give you a higher SPL if that sub is designed for a ported enclosure, at a given power input.
So would building a decent box.
use five-eighths or three-quarters inch MDF available for about $20 for a 4'x8' sheet at any lumber store. make sure the back of the box is not parallel to the hfront where the sub is mounted, to avoid standing wave reflection and cancellation. Use polyfill (pillow stuffing) or egg-crate foam inside the box to help this too. It makes the sub think the box is bigger than it really is.
Also brace the box using 1" pieces of wood as cross-braces to reduce box resonation.
those are just a few hints.
for the port, use a flanged port to avoid port-whistle as well.
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-GlassWolf
Pioneer Stage-4, Orion, DynAudio, Fi
Posted By: sparkyssb
Date Posted: July 11, 2002 at 9:58 PM
Thanks glasswolf but I am still in question... At this point and time, I do not plan to redo the box...only cause Im selling the truck to my brother...if he wants a better box, he can build/buy one... Am I screwed in porting it cause of the dimensons and terrible design? Cause frankly it sounds good in my truck for me but I was wondering if I were to port it (w/flanged port to avoid whistle) if it would sound better than what it already sounds like. Yeah...when i get a bigger truck, im definately going to build my own box w/ the right dimensons and include more than one 10" cheap Lightning Audio sub....hehe.  .........but hey...im a cheap college student. lol.
Posted By: GlassWolf
Date Posted: July 12, 2002 at 10:55 AM
quote of the day:
"If it ain't broke, don't fix it."
If it sounds good, and you're selling it anyway, leave it the way it is. no point in chancing problems, and besides, porting a box involves a lot of math. Not worth the effort there and you need to know the speaker's exact specs.
Lightning Audio isn't so bad really. I use their capacitors and some of their stuff for power distro in my Jeep. Almost picked up one of their Bolt 4-channel amps to play around with it but I ended up finding a PPI amp I wanted and got lucky on that deal.
Anyway you could do a lot worse than Lightning for sure.. I'll leave it at that.
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-GlassWolf
Pioneer Stage-4, Orion, DynAudio, Fi
Posted By: sparkyssb
Date Posted: July 12, 2002 at 12:26 PM
Appreciate the response Glasswolf. Wow...i never knew that porting involved that much. Then again, I have never done this before in my life. Yeah...if it isn't broke, definately don't fix it when it comes to drilling holes and that. Again, thanks. and take care.
Posted By: GlassWolf
Date Posted: July 12, 2002 at 2:14 PM
yup.
a port is tuned to a specific frequency based on a specific speaker's characteristics such as it's free-air resonance, electrical and mechanical Q, ideal enclosure volume, and so forth, all of which plug into formulas to produce the desired tuned frequwncy and enclosure volume.
It's a bit of work but when it's done right it makes all the difference.
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-GlassWolf
Pioneer Stage-4, Orion, DynAudio, Fi
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