Compression; Monitoring The Input Signal - Klark Teknik DN9848E Operator's Manual

5.2.5 Compression (Page 14)
Each input has an independent full-range
compressor to improve the dynamics of the
incoming signal levels. The compressors are
variable ratio and can be set to a hard knee
characteristic for a sharp gain reduction
response at the compression threshold, or soft
knee for a more 'musical' response.
To set the compressor parameters
1
On the first compressor menu page, use the centre DATA ENTRY control knob to select a
threshold value in the range –10dBu to +21dBu, and the right control knob to set a ratio from
1:1 to 5:1.
2
Turn the left control knob clockwise to access the first sub-menu page. Use the centre
control knob to select a hard or soft knee characteristic and the right control knob to set the
bypass state to 'No' so that the compressor is included in the signal path.
3
Turn the left control knob clockwise to access the second sub-menu page. Use the centre
control knob to set the compressor attack time (range of 40µs – 1ms in 20µs steps or 1ms to
100ms in 1ms steps). Use the right control knob to set the release time (10ms to 2s in 10ms
steps).
To switch the compressor out of the circuit
Set the bypass state on the second compressor page to 'Yes'. The other settings are held for
future use.

5.3. Monitoring the Input Signal

Each of the four inputs has a nine-segment signal meter for monitoring the internal signal clipping
and compressor headroom or gain reduction.
The top CLIP segment (shown illuminated in diagram left) monitors the internal signal
clipping. It operates independently of the rest of the meter, illuminating when signal
clipping is detected at any stage in the processing circuits, regardless of whether the
input level is above or below the compressor threshold. Hence, the audio engineer has
full visibility of internal signal clipping that may result in audio distortion.
The 0dB to –40dB signal meter monitors the input level on a relative scale, where the "0"
segment is set at the specified compressor threshold. For example, if the threshold is set
to +9dBu then the input signal meter "0" segment is set at 9dBu true value, and a signal
of –3dBu registers as 12dBu below the threshold (below left). Thus, when the signal level is below
the threshold, the meter indicates the headroom.
When the signal level reaches the threshold, that is, the red "0" segment illuminates, the meter 'flips'
and reads downwards to show the amount of gain reduction applied to the signal.
Signal level below
compressor threshold
12dBu available
headroom
Compressor threshold
11
Input Channels
9dBu gain
reduction
reached