Z-Systems z-CL6 six-channel mastering dynamics processor - Manual (Page 5)

z-CL6 manual
5
The purpose and function of the hipass filters require a bit of explanation. In essence, a
compressor consists of two blocks: a level detection block and a gain control block. The level
detection block senses the level of the input signal and compares it to the user-determined
threshold. When the input level exceeds the threshold, the detection block tells the gain control
block to decrease the output level by the amount specified by the compression ratio. We have
provided a hipass filter that goes before the level control block. This allows you to remove a
desired amount of the low-frequency energy from the input signal so that the low frequencies
don’t trigger the compressor. This may prove to be useful for previewing different bass
management modes for Dolby and DTS surround mastering.
The corner frequency parameter specifies the – 3 dB point for the hipass filter. Below the corner
frequency, the filter has a slope of 12 dB per octave. The corner frequency can be varied from 10
Hz to 990 Hz. The 10 Hz setting is useful simply for blocking DC level from the level detector.
Do not be alarmed by the presence of these hipass filters; remember – they are not in the audio
path, but rather in the level detection path.
The make-up gain function serves two purposes. The first is to allow you to increase the overall
signal level, post-compression. The second is as a digital volume control for controlling relative
levels between the various surround groups. The make-up gain has a range from –95 dB to +12
dB referenced relative to full-scale digital (dBFS).
Saving and Loading Presets
The entire state of the z-CL6 can be saved and recalled. Press the presets button once. This will
bring the z-CL6 to the state shown in Figure 8. To save a preset, use the middle knob (as
prompted by the display) to choose a preset number then press the button beneath the SAVE
indication. This will then bring the z-CL6 to the state shown in Figure 9, which confirms that the
SAVE operation took place.
LOAD
preset #21
(L knob) (R knob)
MIDI #12
SAVE READ DUMP
Figure 5 - preset mode