airspace?
Printed From: the12volt.com
Forum Name: Fiberglass, Fabrication, and Interiors
Forum Discription: Fiberglass Kick Panels, Subwoofer Enclosures, Plexiglas, Fabrics, Materials, Finishes, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=79775
Printed Date: May 12, 2024 at 11:58 PM
Topic: airspace?
Posted By: cml0101
Subject: airspace?
Date Posted: June 29, 2006 at 11:01 PM
how do you figure the airspace on a fiberglass box
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cml
Replies:
Posted By: sawhit4
Date Posted: June 29, 2006 at 11:34 PM
please read all the stickys at the top of the page before posting.
Posted By: crazyoldcougar
Date Posted: June 30, 2006 at 8:32 PM
from rookie to rookie, that was harsh..LOL easiest is packing peanuts...however ANY dry material you can quantify will work...rice, smarties, marbles.. smaller the material used the more acurate the measurement.. ------------- Fiberglass Guru.
Posted By: audiocableguy
Date Posted: June 30, 2006 at 9:51 PM
Got Math?
L x W x H divided by 1728 = cubic feet.
Irregular shapes can be difficult but not impossible to calculate. Your sub box isn't going into space, you can be off a little here or there.
Plus or minus 5% of the recommended volume won't change anything. You might be able to get away with 10%. Adjust the box volume due to the displacement of the basket and magnet. Experiment with polyfill or dacron. Both can help the driver to see a tad bit more airspace than is really there.
Posted By: mustangfoo
Date Posted: July 01, 2006 at 1:05 PM
Yea as audiocableguy said, he was firm in his explanation. Plus that sticky on packing peanuts I think is crap as packing peanuts are quite big and break. I found the cheapest thing to use to find volume in a FG box is rice. I pick up rice for $0.99 for 5 pounds at my local super market, and just recently bought 50 lbs. for my enclosure calculations. Remember, and always remember when calculating volume to accomodate for driver displacement, bracing, supports, etc. etc.
Posted By: Melted Fabric
Date Posted: July 03, 2006 at 12:36 PM
crazyoldcougar wrote:
from rookie to rookie, that was harsh..LOL
LOL, it was, but as far as the forum goes sawhit caught on quick. The delivery was a bit rough. LOL ------------- I have not failed. I've just found 10,000 ways that won't work.
When you do not know what you are doing and what you are doing is the best -- that is inspiration.
Posted By: hifihacks
Date Posted: July 05, 2006 at 3:41 AM
Like they say, water, Packing peanuts, Actual peanuts, as long as you can measure it.
Remember that the volume of the cone and basket of the sub itself will count.
This is not an exact science, it is a car sub woofer, not an electron microscope. The peanuts measurement is just to check that you are not way off. In reality where you put the sub etc will contribute a lot to the sound, you can also adjust it a lot with fill. My advice don't sweat the volume too much, but concentrate on the f'glass lay up - thats the hard part.
Fibreglass tuturial
Fibreglass wheel well sub box-------------
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