565E
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Keep in mind that the threshold level becomes a function of the amount of overall gain through the
equalizer, including the boost. This technique can be used with any frequency that can be con-
trolled by the equalizer.
One occasion for using an EQ in the sidechain is when low frequency signals transmitted through
a desk or podium are triggering the 565Es expander unnecessarily. You can solve this problem by
using an equalizer in the sidechain to remove the low frequencies from the control signal or to
boost the voice-range frequencies in the control signal.
When the offending frequencies are removed or minimized, the relative level of the desired frequen-
cies increases. The expander can now tell the difference between the wanted and unwanted signals.
Use this technique in any situation where levels are nearly the same, but the fundamental frequen-
cies involved are different.
Note
The ability of the expander to discriminate between wanted and unwanted signals is
partially determined by mic technique. Be particularly careful of high frequency sounds
entering the side or rear pattern of a cardioid mic. Most cardioid mics exhibit a sharply
rising off-axis response characteristic at higher frequencies. Check the off-axis curve (the
lower one) in the manufacturers literature. If theres only a 3dB to 6dB difference between
the on-axis (frontal) response and the off-axis (side or rear) response in the 5kHz to 10kHz
reason, high frequency sounds will be picked up by the side or back of your mic.
Use the mics directional pattern to keep other sources as far off-axis as possible - do everything
you can do to extract all the source-to-source discrimination possible through good mic technique.
The sounds picked up by individual mics must be primarily the sound of the desired signal, or the
expander wont be able to tell the difference.
Hint
You can save time, and make life easier, by listening to the output of the equalizer (instead
of the 565Es output) that youre using in the sidechain. Doing this allows you to hear the
signal that will control the 565E, and perhaps to find the range that you wish to emphasize
or de-emphasize more easily.
