NetNews Usenet Archive 1992 #27/NN_1992_27.iso/spool/rec/audio/car/4903

Text File | 1992-11-17 | 1.9 KB | 42 lines

Newsgroups: rec.audio.car
Path: sparky!uunet!utcsri!newsflash.concordia.ca!mizar.cc.umanitoba.ca!access.usask.ca!kakwa.ucs.ualberta.ca!news
From: [e-mail] (Cal Demaine)
Subject: Re: Decreasing Volume in Sub-box
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Organization: University of Alberta Electrical Engineering
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Date: Tue, 17 Nov 1992 16:10:33 GMT
Lines: 29

Appologies if anyone has already said this, but my nnmaster is down, and I am
unable to use anything but (ick!) rn.

You may find that your 3.1 ft^3 box may be closer to 2.5 ft^3 than you think.
If you subtract the volume of the driver and the port, the apparent volume
decreases.

Of course, the manufacturer may have already accounted for the volume of the
driver in the box (not likely) or the port (wildly unlikely).  As well, there
have been mumblings that your internal volume can be off by as much as 10%
without much effect.  (But don't quote me.)  Finally, the manufacturer may
have intended the box to be stuffed, and if you didn't, the internal volume
may be closer to ideal.

But, if you want to easily adjust the volume, then putting dense blocks of
sytrofoam in the cabinet will reduce the apparent volume.  Basically, anything
that's not air-permiable and occupies space will work Ok.  Oh, yes, and it
shouldn't deform too much. (IE: Not jell-o)

Finally, if you haven't, I strongly recommend checking the tuning of your
box after you're finished fooling with the size.  Being even a few hertz
off in the tuning can seriously change the system's response.

If anyone doesn't know how to check the tuning, I'll post the method.

  - Cal
--
  - Cal Demaine                   | The university may own my ideas and opinions
    ([e-mail]) | but don't think for a moment they share them