User manual KURZWEIL ALGORITHMS2

[. . . ] FXAlgs #724-6, 728: Distortion FXAlgs #724-6, 728: Distortion FXAlg #724 Ñ Mono Distortion FXAlg #725 Ñ MonoDistort + Cab FXAlg #726 Ñ MonoDistort + EQ FXAlg #728 Ñ StereoDistort+EQ Small distortion algorithms Allocation Units: 1 for Mono Distortion; 2 for MonoDistort + Cab; 2 for MonoDistort + EQ; 3 for StereoDistort + EQ Mono Distortion sums its stereo input to mono, performs distortion followed by a hipass filter and sends the result as centered stereo. L Input Distortion L Output R Input Block diagram of Mono Distortion R Output MonoDistort + EQ is similar to Mono Distortion except the single hipass filter is replaced with a pair of second-order hipass/lowpass filters to provide rudimentary speaker cabinet modeling. The hipass and lowpass filters are then followed by an EQ section with bass and treble shelf filters and two parametric mid filters. L Input Distortion Cabinet EQ L Output R Input R Output Block diagram of MonoDistort + EQ StereoDistort + EQ processes the left and right channels separately, though there is only one set of parameters for both channels. The stereo distortion has only one parametric mid filter. L Input Distortion EQ L Output R Input Distortion EQ R Output Block diagram of StereoDistort+EQ Algorithm Reference-94 FXAlgs #724-6, 728: Distortion MonoDistort + Cab is also similar to Mono Distortion except the hipass is replaced by a full speaker cabinet model. There is also a panner to route the mono signal between left and right outputs. [. . . ] At short release times, the compressor will open up almost as soon as the signal drops. For typical compressor behavior, the attack time is considerably shorter than the release time. At very short attack and release times, the compressor is almost able to keep up with the instantaneous signal levels and the algorithm will behave more like distortion than compression. In addition to the attack and release times, there is another time parameter: ÒSmoothTimeÓ. The smoothing parameter will increase both the attack and release times, although the effect is significant only when its time is longer than the attack or release time. Generally the smoothing time should be kept at or shorter than the attack time. You have the choice of using the compressors in feed-forward or feedback configuration. For feed-forward, set the FdbkComprs parameter to ÒOutÓ; for feedback compression, set it to ÒInÓ. The feed-forward configuration uses the input signal as the side-chain source. The feedback compressor on the other hand uses the compressor output as the side-chain source. Feedback compression tends to be more subtle, but you cannot get an instant attack. In the feed-forward configuration, the signal being compressed may be delayed relative to the side chain compression processing. The delay allows the signal to start being compressed just before an attack transient arrives. Since the side chain processing ÒknowsÓ what the input signal is going to be before the main signal path does, it can tame down an attack transient by compressing the attack before it actually happens. In the feedback configuration, the delay affects both the main signal and the side chain, and so is of limited usefulness. A meter is provided to display the amount of gain reduction that is applied to the signal as a result of compression. Parameters: PAGE 1 In/Out FdbkComprs PAGE 3 Atk Time Rel Time SmoothTime Signal Dly 0. 0 to 228. 0 ms 0 to 3000 ms 0. 0 to 228. 0 ms 0. 0 to 25. 0ms Reduction -dB 40 In/Out Out Gain 20 12 8 6 4 2 0 Ratio Threshold MakeUpGain 1. 0:1 to 100:1, Inf:1 -79. 0 to 0. 0dB Off, -79. 0 to 24. 0 dB In or Out In or Out Out Gain Off, -79. 0 to 24. 0 dB When set to ÒInÓ the compressor is active; when set to ÒOutÓ the compressor is bypassed. To compensate, the output gain parameter may be used to increase the gain by as much as 24 dB. Note that the Out Gain parameter does not control the signal level when the algorithm is set to ÒOutÓ. Algorithm Reference-140 FXAlg #950: HardKneeCompress ¥ FXAlg #951: SoftKneeCompress FdbkComprs Atk Time Rel Time SmoothTime A switch to set whether the compressor side chain is conÞgured for feed-forward (Out) or feedback (In). The time for the compressor to start to cut in when there is an increase in signal level (attack) above the threshold. The time for the compressor to stop compressing when there is a reduction in signal level (release) from a signal level above the threshold. It is intended to smooth the output of the expanderÕs envelope detector. Smoothing will affect the attack or release times when the smoothing time is longer than one of the other times. [. . . ] The Invert parameters provide a polarity reversal to the input signals. The Invert parameters are actually redundant since Out Mode provides signal inversions as well. The left and right Out Mode parameters may be set to any of the following: L R (L+R)/2 (L-R)/2 -L -R -(L+R)/2 (R-L)/2 left channel right channel normalized sum of left and right normalized difference of left minus right polarity reversed left channel polarity reversed right channel polarity reversed and normalized sum of left and right normalized difference of right minus left You may well ask why you would want to meter or monitor reversals or sums or differences of your stereo channels. One important case is to determine if your final mix is mono compatibleÑvery important if your mix is ever going to be broadcast on radio or television. [. . . ]