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AM-10HD / Aug 2008
F E A T U R E S A N D P R E S E T S
energy (loudness) in the frequencies where the majority of consumer’s receivers can
hear it and without wasting energy in the frequency extremes where only a small
percentage of consumer radios have any response.
Can I Generate That “Sixties” Compression Sound?
Yes! The way to do this is to purposely drive the multiband section harder and then
trade off the slower acting AGC against the faster time constants of the compressors.
This is accomplished by (1) operating the AGC attack times fairly slow (>500mS)
and (2) operating the AGC Backoff control at negative numbers greater than about
‑2.0dB which causes more gain control to be accomplished using the faster compres‑
sor time constants. If you are careful to not run the Backoff control too far negative,
the AGC will provide a “platform” that the compressor can work against, preventing
rapid suck‑up of background noise that might be undesirable.
A word of caution if you’re also using reverb to augment that “sixties” sound…
with faster and deeper compression reverb tails will become exaggerated. This ar‑
tifact can be reduced in several ways:
‑ Reduce the amount of reverb;
‑ Operate the AGC Backoff control at slightly less negative numbers;
‑ Reduce the overall drive to the AGC/Compressor section;
‑ Raise the Freeze Threshold to less negative numbers and decrease the Freeze
Wait time to something under 100mSec.
You can use these methods alone or in combination to control reverb tails. Alter‑
nately, if your station’s sound demands a fair amount of reverb during non‑speech
programming, then announcer microphones will almost certainly become a challenge.
In this scenario you may have to come up with a way to reduce the contribution of
the reverb, but only when talent microphones are on.
