What is a Compellor? In short it is a Compressor-Leveler-Limiter. The device is specifically designed for the transparent control of audio levels. It operates as a stereo processor or as a two-channel mono processor supporting independent channel control. The original device model Stereo Compellor was released in
|Published (Last):||22 June 2004|
|PDF File Size:||14.76 Mb|
|ePub File Size:||11.99 Mb|
|Price:||Free* [*Free Regsitration Required]|
Quick Links. Download this manual. Copyright Aphex Systems Ltd. All rights reserved. Printed in U. Written and produced by Donn Werrbach. Table of Contents. No user serviceable parts inside. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.
Page 3: Contents A Compellor 2. Quick Start - Page 6 3. Introduction - Page 7 4. Installation - Page 10 5. Specifications - Page 14 3.
Page 4 A Compellor 6. Operation - Page16 6. Page 5 Page Page 6: Quick Start A 2. Quick Start Compellor You can use this quick setup to get a signal through your Compellor right away.
Page 7: Introduction 3. Introduction 3. A Compellor is the first and only product designed specifically for the transparent control of audio levels.
While other audio processors are designed simply to compress and limit audio signals, a Compellor is designed to intelligently manage the dynamic range of audio without causing noticeable changes to the character and feeling of the sound. Finally, in , an agreement was reached between Werrbach and Marvin Caesar, the president of Aphex Systems, to produce the Compellor as a product line.
With the FDL, Compellors became even more transparent and useful than ever before. Page Installation A Compellor 4. Nevertheless, Aphex recommends making a careful inspection of the ship- ping carton and the contents for any signs of physical damage. Page Power Cord 4. The appropriate mains plug for each country is normally shipped with each unit. Page 13 The output impedance of 65 ohms is optimized for driving long cables and consequently l l e Unique servo balanced output circuitry automatically maintains the proper gain and level into a balanced or unbalanced output line.
Output connections are made by means of 3-pin male XLR jacks. The pinout follows the same conventions as the input jacks described above, and you should exercise the same care about wiring as described for input wiring. Page Speci Cations A Compellor 5. Page Ratio 5. Page Operation A 6.
Operation Compellor 6. You will get a good feel for what is going on, and you will have a signal going through the processor, ready for fine tuning. Page Video Post Production has too wide a dynamic range, it can cause broadcast processors if the processing does not include the Compellor to work too hard and generate audible artifacts.
These are all reasons to master a final mix which has a controlled dynamic range. Operation Compellor numerous other devices which effectively control the level differences, but none have the transparency of the Compellor. Adjust the Compellor so that its output is driving the downstream processors at their sweet spot. Page Hard Disk Recording 6. When building a broadcast or webcast music library on a hard disk audio server, it would be nice to have a way to even out those levels so the on-air segues will always be smooth and fat.
Page System Description A 7. System Description Compellor 7. The input audio signal undergoes all processing in the VCA stage and is subsequently sent out through the output stage.
A side chain system produces the control signals which change the VCA gain according to the signal processing requirements. Page Compressor Function 7. While the leveler is relatively slow responding, the com- pressor works much faster to control both the transients and other quick changes in the sound level.
The first mode links only the leveling systems of the two channels. The second mode links both leveling and compression. You cannot link compression only. Page Output Control 7.
In this case, the bar is entirely green except for a possible red dot which floats within the green bar. Page Appendices A Compellor Appendix A: Balanced and Unbalanced Lines and Operating Levels Interfacing all types of equipment with balanced and unbalanced lines and can sometimes be trouble - some. First you have to somehow connect balanced to unbalanced and then you have to deal with dif - ferent levels.
Page 27 A Compellor is cancelled out by the di erential ampli er. Figure 1 illustrates how the hum is induced into both wires equally and therefore is cancelled out. Since the balanced line has wires that are twisted together, each wire tends to pick up the same amount of induction from external sources. Page 28 A Compellor There are basically three ways to attack the prob - lem of a ground loop. First is to eliminate it from its source, and the second is to re-route it through another path.
The third is to balance out your unbal - anced audio interfaces. For unbalanced wiring you should use high grade, low capacitance shielded wire for best results. Generally, a minimum 1: 10 ratio is possible. This has become modern practice and all balanced inputs are normally running 10K ohms or higher impedance.
Page 31 output circuit. We strongly recommend that you refer to your various equipment manuals to nd out what is used in each case before hooking up to unbalanced lines. The following diagrams show you how to properly unbalance each type of output. If you follow these instructions, you should have no problems.
We could mix and track on the VU meters, knowing there is 20dB of headroom in the digital domain for peaks. That is because some specs relate to peak measurements and some to average or RMS measurements.
Page 37 room above the maximum PPM indication. By controlling the audio levels to maintain good PPM readings, there can be no possibility of the electronics clipping the audio.
The disad- vantage is that to maintain a good average volume level, it takes very clever people riding the gain who can accurately guess at the crest factor of all the sounds. Digital audio technocrats are dictating technology from their laboratories far away from where people create and produce art. Page 39 Most simply stated, the Compellor will accept an audio input, digital or analog, level it out and add some compression making it more consistent in average level.
The resulting aver- age output level will target around 0VU. Page 40 A Compellor outputs into the codec, the level will then shift and be louder with the analog input. That may give the effect of a fuller on-air sound when the coder is driven by analog because the on-air audio processor at the decoder side is driven with higher input level. Page 41 Page Print page 1 Print document 41 pages. Cancel Delete.
Sign In OR. Don't have an account? Sign up! Restore password. Upload from disk. Upload from URL.
The patented technologies within the D are totally unique. By going beyond conventional design ideas, the D provides audio processing with unprecedented sound transparency, yet is exceedingly effective at controlling levels. No other product can match the performance of the D. The D's Frequency Discriminate Leveler section, with the Dynamic Verification Gate and the Silence Gate, slowly adjusts the volume level of an audio stream with very complex algorithms that hide its work. It works differently at different frequencies and stops processing when the sound stops, then resumes instantly when the sound reappears, so there's no distracting increases in program background noise. When you listen, you know the levels are made more even, but you don't perceive the levels are shifting.
Aphex Compellor 320A Owner's Manual