TL Audio 5051 - Manual (Page 16)

The Knee switch enables the 5051 to be operated in two different modes - soft
Knee or hard Knee. Soft knee mode offers a gentle compression curve around
the threshold point, and is traditionally employed to yield a more subtle,
musical type of compression effect. The hard knee setting causes the full
compression ratio to be applied immediately the signal has passed the
threshold point, so tends to produce more pronounced and severe
compression.
4.15 Gain Make Up.
While the subjective sound quality of the signal can be improved by
compression, the overall signal level will be reduced when gain reduction is
taking place. The Gain Make Up control is designed to boost the compressed
signal by between 0 and 20dB, in order to bring back the level to the same
loudness as the uncompressed signal. Without this control, comparing the
original and compressed signals becomes difficult, since there would be a
level drop each time the compressor is switched in: therefore it is normal to
adjust the Gain Make Up control so that when the ‘compressor on’ switch is
activated, the audio signal remains constant in level.
Unlike the Output Level control, the Gain Make Up control is active only when
the ‘compressor on’ switch is engaged. Once the Gain Make Up has been
adjusted, use the Output Level control to set the overall output level of the
5051.
4.16 Compressor
On.
This switch enables or disables the compressor stage, thus allowing an A/B
comparison to be made between the original untreated signal and the
compressed signal. Any gain make up applied to the signal only becomes
active when the “Compressor On” is enabled. An associated status LED
indicates when the compressor is active. The Gain Reduction on the VU meter
will monitor the level of compression regardless of the compressor stage being
active or non active.
4.17 Frequency Conscious Compression.
The provision of a sidechain insert point on the 5051 allows the unit to perform
frequency conscious compression, such as ‘de-essing’. This is achieved by
patching an equaliser (normally a parametric or graphic type) into the
sidechain (the insert point works on a send-and-return principle whereby the
insert ‘send’ connects to the equaliser input, and the equaliser output connects
to the insert ‘return’, thus completing the circuit). Once connected, any
frequency boosted on the equaliser will effectively lower the compression
threshold at that frequency. To de-ess, for instance, use a parametric EQ
patched into the insert point and try boosting the sibilant frequency (normally
3-5kHz) using a narrow bandwidth setting on the EQ. This should make the