Alto Professional ACOM2 - Manual (Page 8)

8
APPLICATIONS
ACOM2 can be used in a variety of situations:
Compressor - If an audio signal exceeds the set threshold, the signal will be reduced in gain proportional to
how much it exceeds the threshold.
Ducking - Ducking automatically reduces the volume of background music whenever an external source is
detected (e.g., when an announcer begins to speak). To use the compressor as a ducker, plug the
announcer's mic into a mixer and route that mic signal to the compressor's Sidechain Return. Plug the music
source into ACOM2’s inputs. Set the compressor controls like this:
• Threshold: +3 dB
• Ratio: 6:1
• Attack: ~1 ms
• Release: ~1 sec.
• Turn on the Smart switch for SKC Mode
When the announcer speaks, the music will be "ducked." Increase the ratio to duck it even lower. When the
announcer finishes speaking, the music will fade back in at the rate set by the Release knob.
Limiter - Set ACOM2 with a high ratio and a high threshold. Softer sections will remain uncompressed, while
louder peaks will be kept under control. Set the Threshold so that the loudest sections get around -6 dB of
reduction, set the Ratio for 6:1, and turn on the Smart switch for SKC mode.
Noise gate - ACOM2's compressor can be used as a noise gate to block unwanted signal (hiss and noise)
below a set threshold, so only the intended instrument signal is heard. When the instrument's signal stops,
dropping beneath the threshold, the gate will activate, and the noise that you'd normally hear will be muted.
De-Essing - When recording vocals, high frequency "s" sounds can jump out louder than the rest of the
audio. By placing an equalizer (like the AEQ231) in the sidechain, you can set the compressor so that only
certain frequency ranges trigger ACOM2's compressor. Set the EQ to cut all frequencies except for the
sibilant range, between 3-6 kHz. Then, set ACOM2 like this:
• Threshold: ~0 dB
• Ratio: 6:1
• Attack: 1 ms
• Release: ~0.1 ms
Expander - An expander is a compressor in reverse. It increases the dynamic range of the audio signal,
making quiet sounds even quieter by reducing the level of a signal below a set threshold level. Signals above
the threshold remain at unity gain, and signals below the threshold are reduced in gain.
RACK MOUNTING
For secure mounting, you can mount ACOM2 into a standard 19" rack space unit (available from various rack
manufacturers or your music dealer). Allow at least an additional 4" depth for cabling on the rear panel. Be
sure that there is enough air space around the unit for sufficient ventilation, and do not place ACOM2 on
high-temperature devices (e.g., power amplifiers) to avoid overheating.