Mackie Quad Gate/Compressor Owner's Manual - Page 16

QUAD-COMP/GATE 36. BYPASS button 38. ON button This button will bypass the selected channel's compressor, and the audio will pass through unaffected by the compressor controls. (This does not affect the Gain Reduction metering.) 37. GAIN knob This allows you to adjust the amount of make-up gain applied to the current channel. Make-up gain is used to return the compressed signal to it's original level and place in audio society, once it has been compressed. The reduction meters will help you see how much the overall level is reduced during compression, and your ears will help you bring the level back up to match your other instruments or microphones etc. The gain adjustment ranges from 0 dB to 20 dB. This button engages or disengages the key filter circuit. This allows you to quickly compare the action of the key filter on compression. When this button is out, the key filter knobs will have no effect on the compressor. 39. CENTER FREQ knob This allows you to sweep the audio band with a filter whose bandwidth is selected by the BANDWIDTH [40] knob. Press this knob for 2 seconds to listen to the key filter only, as you boldly seek out frequency ranges containing peaks, or parts that could use some compression. Then the selected range will be used to detect when compression is triggered on your channel signal. The control ranges from 20 Hz to 20 kHz. Compressor Key Filters 40. BANDWIDTH knob The compressor's detector circuit receives a copy of the incoming signals, detects when compression should occur, and applies the compression and all its parameters to the incoming signals. LEVEL DETECTOR KEY FILTER AND CONTROLS The width control will change the bandpass filter to allow for a wider or narrower frequency range to be used as the key filter. Compressor Key Filter listen INPUT OUTPUT The key filter is placed before the detector, so you can adjust the signals reaching the detector. For example, you can adjust it so the compression will not be triggered by the bass thumping, but it will if there are certain peaks above the threshold in the vocal range. (The frequency and bandwidth controls are only applied to the signal going to the detector and not to the main audio output.) Note: If the SIDECHAIN [35] button is engaged, the signals going into the SIDECHAIN RETURN [4] for the selected channel will be used to trigger the compression instead of the channel input. The key filter is still in operation if ON [38] is pressed in. SIDE CHAIN INPUT LEVEL DETECTOR KEY FILTER AND CONTROLS INPUT OUTPUT Pressing and holding either key filter knob in for two seconds will illuminate the bottom LED of the knob, and place the channel in key filter listen mode. In this mode the channel will output only the compressor's key filtered signal, allowing you to quickly identify target frequencies by ear. For an example of how to use the key filter, suppose you have the compressor connected using channel inserts (as in figure 1 on page 6). It receives the individual channel signals and sends them back to your mixer: 1. On your mixer, remove the channel from the main mix. 2. Solo that channel to the headphones. 3. Engage the key listen by pressing and holding either of the key filter knobs on the Quad Comp/Gate for 2 seconds. 4. Use the key filter frequency and width controls to identify the frequency range to trigger compression. 5. Make appropriate compressor parameter adjustments (i.e. tweak 'til it sounds good). 6. Adjust the make-up gain to compensate for the gain reduction due to compression. 7. Disengage the key listen. 8. Bring the signal back into the mix. 16 QUAD COMP/GATE