[IRCA] Is audio compression in your toolbox?

[satya@xxxxxxxxxxxx]

Hi all:

Does anyone out there use an audio compressor?  I started using a
dbx-266XL audio compressor, and on these quiet winter nights have gotten
some good results.  Basically, if there is a strong local (or strong
anybody) with a DX station underneath, tantalizing you with quiet audio in
between pauses of the dominant station's programming, the compressor will
automatically bring up the audio level of the DX station during those
pauses, making the DX station momentarily audible, sometimes with armchair
copy.  It's sorta like AVC/AGC, only on the AF stage (correct me if I'm
wrong, but RF AVC/AGC won't do this because the dominant station's carrier
is still there in between the pauses).

For example, KGNW-820 makes that frequency tough here near Seattle,
although I can hear murmuring underneath.  With the compressor, I have now
heard a couple good "WBAP" IDs out of Texas, heard during a KGNW speaker's
brief pause.

The dbx-266XL has selectable attack and release times, all the way to
zero, which is the setting I use.  At zero attack/release and high
compression ratios, to the ear it almost sounds like flipping a switch
between two stations it's so abrupt: quite unnatural sounding to the ears,
but rather effective for DXers.  Also, the 266XL is a stereo rig, so you
can hook the two channels up in series to really flatten things out.

This works best in quiet conditions - otherwise the 266XL will just be
amplifying noise in-between the pauses, or with a lot of noise may not see
much of a difference between program and pause and therefore not do much
of anything.

Another benefit to audio compression is that it levels out the audio level
so that your audio recorder gets pretty much a constant input.  My Olympus
WS-320 audio recorder appreciates a contant audio source within a certain
range, and I no longer get distortion (input too high) or weird-sounding
digital artifacts (input too low). I have an MFJ-784B outboard DSP, which
also likes the audio to be in a very narrow band for maximum results, and
the dbx is ideal for that.

Finally, the 266XL is also an expander, in that it can do the opposite:
cause the quiet spaces to be diminished into nothing, making program
listening with annoying hiss in the background more noise-free.  The same
concept was used for dbx's noise-reduction units.  For example, I like to
listen to CBK-540 programs, and an expansion ratio of about 1.4:1 knocks
down the static and low-level pests quite nicely during programming
pauses.  Since most stations audio-compress their programming anyway, it
makes the target station sound more life-like to boot.

And yes, the dbx can be used with the Sony SRF-59.....

Kevin S
Bainbridge Island, WA

The dbx 266XL can be had for under $100 used, and dbx makes incredibly
well-built gear.


_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx