Input Compressor — Crown I-Tech HD, PIP-USP4 & VRack12000 / VRack4x3500

The Input Compressor/Limiter block contains input compression controls for the channel of the amplifier indicated on the title bar. When input compression is turned on, if the input level exceeds the threshold set, compression takes place according to the selected compression ratio. Compression or limiting is provided at the input stage of a component.

Controls and meters in the Input Compressor/Limiter Block include:

Input Level

This meter indicates the input level going into the compressor processing block.

Compressor Output Level

This meter indicates the output level of the compressor processing block.

Input Compression Enable

This button activates or deactivates input compression for the selected channel.

Threshold

The Threshold control sets the level that the input must exceed before compression is activated. The value can be set either through the numeric spin box or by dragging the handle in the graph.

Compression Ratio

The compression ratio controls the amount of compression that is applied for each step of input above the threshold. The range of control is 2:1 through 32:1. You can set the compression ratio in two ways: either by using the display handle at the right of the chart to set the ratio or the dedicated Compression Ratio numeric spin control.

Knee Width

This control will allow you to determine a “soft roll on” where the compressor is gradually modified from the unity gain to the final compressed gain. The spin control is used to set a range in dB before the actual threshold through which the compressor gain is gradually modified from unity to the final compressed gain.

Attack Time

The Attack Time control sets the amount of time it takes to attenuate the input signal from unity gain to the amount of reduction indicated by the ratio. The range of control is 10 milliseconds through 2 sec.

Release Time

The Release Time control sets the amount of time it takes to increase back to unity gain (no change) after the input signal has dropped below the threshold. The range of control is 100 milliseconds through 30 sec.

Make-Up Gain

This numeric spin control has a range of 0dB of gain (unity) to +20dB of gain. The step size is ½ dB.

Gain Reduction Meter

The Gain Reduction Meter indicates how much the level is being reduced by the Compressor. The meter indicates more reduction by showing the meter moving downward.

Quick Setting Buttons

Slow

Clicking this momentary button will set the following values (the other controls remain unchanged):

Medium

Clicking this momentary button will set the following values (the other controls remain unchanged):

Fast

Clicking this momentary button will set the following values (the other controls remain unchanged):

Link Button

The link button links the two channels of the compressor so that if either channel is in compression the other channel will compress as well. This button will be greyed out, indicating that it is unavailable if the other channel of the compressor block is not enabled. This button will also be disabled if the amplifier is not in Dual mode.

Additional Information

If you are connected to the Internet you can find additional information, including  video overviews at:
http://www.crownaudio.com/tutorials/