OK, I understand now. The Gates company (of long ago broadcast
equipment fame) made a device they called the "Level Devil" - which
worked this way. I had one, and it worked wonders in improving false
vox trips. The Level Devil served as a downward expander for signals
less than the crossover point, and as a compressor for signals above the
threshold. Marvelous gadget - I wish I still had one.
- Jim, KL7CC
Iain MacDonnell - K6IAM wrote:
google is a wonderful tool...
http://www.doctorproaudio.com/doctor/temas/dynamics-processors-noisegates_en.shtml
"Downward expander. This type of unit works like the opposite of a
compressor, and provides a "ratio" control or attenuation slope. That
way the signal is attenuated more highly the lower the signal level
is. In fact, if the threshold is set high enough, we could "expand"
the dynamics of the signal, increasing its dynamic range, though this
is not normally done. The attenuation ratio works in an equivalent way
to that of the compressor, defining the amount of a attenuation
(compression) that is applied to the signal. These ratios are
expressed in dB, so that, for example, 1:6, means a signal that is 1
dB below the threshold will get reduced to 6 dB below it, while a
signal 3 dB below the threshold will get reduced to 18 dB below it.
Likewise, a 1:3 (one to three) means a signal 1 dB below the threshold
will be attenuated 2 dB (as the level will go from -1 dB to -3 dB; we
use a negative sign as these levels are below the threshold, which is
the 0 dB reference in this case). With a ratio of 1:10 and higher, the
expander is considered to work as a pure noise gate, though an ideal
gate would have a theoretical ratio of 1:infinity (any level below the
threshold would be totally muted). "
~Iain
Jim Wiley wrote on 09/ 1/08 11:16 AM:
I give up. What is a "downward expander"? It that the same as a
compressor? Or is it something that has a "crossover point" that
has one action on one side of the crossover, and the opposite
action on the other side? All these newfangled terms are simply
amazing to us OFs.
- Jim, KL7CC
Lyle Johnson wrote:
An experimental Downward Expander will be available in the K3
firmware in the near future. It has been undergoing some limited
testing already
_
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