TL Audio 5050 - Manual (Page 15)

drops back below the threshold. The 5050 Attack and Release controls each
allow a choice of ‘Fast’ and ‘Slow’ modes. The Attack times are 0.5mS (Fast)
and 20mS (Slow), while the Release control is set for 40mS (Fast) and 2S
(Slow). There is an element of automatic operation of the Attack and Release
on the 5050: for instance, should a very short transient occur the time
constants tend to become shorter, to prevent a slow release leaving a “hole” in
the signal after the transient. Also, a fast release setting will be extended by a
slow attack setting.
The speed of the Attack and Release should in general be able to work with
the tempo of the signal. For example if the signal is a snare drum, by
monitoring the gain reduction it is possible to set the Release to allow the
compression to fully recover (i.e. the gain reduction meter will settle back to
0dB) before the next snare beat. This prevents the second snare beat being
reduced in level in comparison to the first. One side-effect of having an
incorrect release setting is distortion on low frequency signals, which can
particularly occur when using a fast release setting on bass heavy signals - the
compressor is forced in and out of compression during one cycle of the
waveform, and distortion results. The 5050 has a built-in “Hold” facility which
delays the onset of release for approximately 10mS after the input signal falls
below the threshold. If distortion is still experienced, a slower release time
should be used.
4.15 Knee.
The Knee switch enables the 5050 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.
4.16 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