NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/rec/audio/19181

Internet Message Format | 1993-01-23 | 1.9 KB

Path: sparky!uunet!cs.utexas.edu!uwm.edu!csd4.csd.uwm.edu!randyd
From: [e-mail] (Randall Elton Ding)
Newsgroups: rec.audio
Subject: Re: Speaker vent placement question
Date: 22 Jan 1993 22:16:51 GMT
Organization: Computing Services Division, University of Wisconsin - Milwaukee
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Message-ID: <[e-mail]>
References: <[e-mail]>
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In article <[e-mail]> [e-mail] (ray s wakeland) writes:
>also see why a designer of a larger floor-standing speaker would put the
>port in back.  For example, the drivers of my B&W DM640's cover most of the
>front surface of the speaker, so it is probably just easier to put the port
>in back.  This speaker is not meant to go near the wall.
>
>I am mistified, however, by the Energy 22.3's.  These speakers have TWO
>ports, one in front, below the woofers, and one in back in the center of the
>speaker.  Why would they do this?

I have experimented with different port positions on the subwoofers I built
over the years and have not found any differences.  The only thing that
seemed to make a difference after I got the box and port volume correct was
the room placement.

On a bookshelf speaker I could see there would be a preference to place
ports on the front, other than that I have not observed anything unusual
about any particular port placement with only one exception...

I built a set of stage speakers (combination horn/bass reflex design) which
were used in a DJ setup dance hall, designed by Altec Lansing.  The ports
on these speakers were just as big as the throat of the horn.  It seemed as
if the further away you got from the speaker, the more the sound seemed to comme
from the port ( I had a buddy cover up the horn and port alternately for the
test ).  So in some special cases it makes a big difference where the port
goes.

Randy.