Sub Enclosure Size
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=61623
Printed Date: May 01, 2024 at 8:19 PM
Topic: Sub Enclosure Size
Posted By: JoeMetal
Subject: Sub Enclosure Size
Date Posted: August 18, 2005 at 11:46 PM
What happens when you put a sub in a box that is larger or smaller than the recommended size for that sub. I was considering making a custom fiberglass box for my car, but I wasn't sure what would happen if I miscalculated the volume.
And regarding ports, how much room do you need around the inside end of the port. Like, if I were to use an 8" port in a part that is only, say, 10" deep, is that a problem?
Thank you.
Replies:
Posted By: dwarren
Date Posted: August 18, 2005 at 11:51 PM
I would highly recommend going by the manufacture's suggestion. Grant it there is alwasy room to fudge. You may encounter differences in the driver's performance. For a BROAD example; using a sealed box that is smaller than recommneded will result in less low end power but produce a more punchy bass that will perform better in the higher frequencies. The opposite theory will apply to a larger box. I wouldn't recommned deviating too much in volume though. Port sizing is more important and there is no geusstimation (is that a word?) with this, you need it to match the box and woofer requirements. I might suggest you contact the tech support for the woofer, they can often times model up enclosures for you if you give them the space limitaions. -------------
Posted By: JoeMetal
Date Posted: August 19, 2005 at 12:03 AM
I guess I'll just go with a sealed enclosure then.  I'm also going to try to stick as close as I can to the recommended volume, but I wasn't sure if it was going to be disastrous if I was a little off.
Thanks for the info.
Posted By: stevdart
Date Posted: August 19, 2005 at 12:04 AM
Like, if I were to use an 8" port in a part that is only, say, 10" deep, is that a problem? It could be if the port diameter is greater than 2". Leave space of at least as great as the port diameter between the end of the port tube and any obstructions. In your case, a bend in the port...or the port exiting another side of the box, could be the solution. Look at this pic copied from WinISD for the reason why: 
The free end extension is actually a part of the acoustical port, which means: that space has to be there. The physical port...the part that you construct and can actually see.. is just a part of the actual port. Leave space of at least the diameter of the port so that you can be sure you have left enough room for the acoustical port to function properly.
-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: dwarren
Date Posted: August 19, 2005 at 12:08 AM
If you are off by a little, like a couple of tenths of cubic feet, don't worry, besides you can add some polyfil and get different results w/o having to rebuild it. Keep in mind if you go too big, you can always add interior space with mdf or soemthing. There is a simple but not so precise way to measure internal volume by using packing peanuts, check it out on the fiberglassing forum up top. By the way, I didn't mean to discourage you from building a ported box, I like them too. -------------
Posted By: JoeMetal
Date Posted: August 19, 2005 at 12:11 AM
I wasn't sure if I should use a port at all. From what I've been told, sealed enclosures have tighter bass, while vented enclosures tend to have more rumbly bass. I'm more of a fan of tighter bass, but I have a Rockford T1 sub and the T2 subs aren't even recommended to be in a sealed box, so I figured I was right on the threshold and it might be a better idea to start delving into the porting world.
|