Aphex Dominator II
Precision MultiBand Peak Limiter
Models 720, 722
Why is the Dominator So Special?
A very significant problem with wideband processing is “spectral gain intermodulation” which occurs when one part of the spectrum controls the level of another part. A typical situation is a vocalist being “sucked down” every time the kick drum hits.
Since most energy is contained in the lower frequencies, they tend to control the level of the entire spectrum. When the lower frequencies are above the limit threshold the higher frequencies are attenuated thus causing the output to sound dull.
Multiband processing solves these problems by splitting the audio into two or more frequency bands and processing each band separately. However, more bands often result in many more parameters to control including a method of summing the bands together again. While giving the user flexibility, it also requires different settings for almost every different source.
The Dominator ll uses program dependent, intelligent circuits to reduce the number of controls. The user, therefore, has flexibility to shape the sound while quickly and easily achieving the goal of consistent, effective limiting.
The Secret Ingredient: ALT
A multiband processor splits the audio into separate bands, limits each band individually and then sums the bands together again. Even though each band’s peak output is predictable, summing the bands together produces an unpredictable peak output.
One conventional approach to making the summed output predictable is to use a wideband limiter after the summing. This, however, introduces all the drawbacks of wideband limiting discussed above.
Another approach is to use a clipper on the summed output. This causes too much clipping distortion if the summed output is too high. In order to avoid this distortion the limiters’ thresholds are set very far below the clipper threshold. The drawback is a loss of loudness and, due to the lower thresholds, much greater amount of processing.
The Dominator ll uses a patented method to produce a predictable peak output while maintaining maximum loudness without audible distortion- the Automatic Limit Threshold (ALT). The outputs of the three bands are summed and sent to the ALT detector circuit. If the sum exceeds a reference value, the ALT reduces the thresholds of the individual limiters. When the summed output falls below the reference value the limit thresholds return to their original setting.
The ALT circuit has a
Both parameters are set by the Density control. When the Density control is set higher, the ALT reference gets closer to clipping, and the attack time is slower, producing more clipping. The opposite occurs when Density is set lower. The “0 RCH” position for the Density control emulates the standard parameters of the original Studio Dominator Model 700, and is recommended for general use.
PROCESS OFF/ON - | LF EQ - adjust input |
level to the low | |
switches the audio | frequency band ±5dB. |
through the unit or | Center detent is flat |
through bypass relays. | response below limiting. |
Model 720
| STERE |
RELEASE - adjusts | forces |
band to | |
release time of the | limiting |
limiters between | the oth |
150mSec (fully | band in |
clockwise) and 7Sec | has a g |
(fully | limiting |
INPUT GAIN - adjusts input level ±15dB. Center detent is unity
XOVER 1 - switches the crossover point between low and mid
HF EQ - adjusts input | XOVER |
level to the high | crosso |
frequency band ±5dB. | mid an |
