The Audio Masterclass Professional Course in Compression

All enrollments have a 30-day no-questions-asked, full-refund guarantee

Confused about compression and dynamics? Ready to master all of its techniques and tricks? Start here…

The Audio Masterclass Professional Course in Compression & Dynamics – Full online course leading to your Audio Masterclass Certificate on completion.

  • The problem: There are a number of different types of compressor, all with many controls to master. Simply ‘playing’ with the controls doesn’t get you anywhere useful.
  • The solution: A twelve-module course that will show, explain and demonstrate how compressors work, and how you can use them to advantage on vocals, instruments, and complete mixes.
  • Your achievement: An understanding, both broad and detailed, of how to get the best from your compressors, with relevance to both hardware and software.

Gain great skills with great training

  • Twelve-module online course
  • Audio examples in every modules, all downloadable to keep permanently
  • 12 practical assignment projects
  • Assessment of your practical assignment projects (requires upgrade)
  • Tutor support
  • Student advice team
  • Complete in 12 weeks or spread your course out over up to one full year or longer.
  • Study when and where you like
  • Available worldwide (we have students in more than 120 countries)
  • Your Audio Masterclass online Student ID (you can use this to seek discounts on software and equipment)
  • Your Audio Masterclass Certificate on completion of your course
  • 30-day full-refund, no-quibble guarantee

Twelve modules – everything you need in compression from start to finish

  • Compressor controls – Threshold, ratio, gain make-up and the gain reduction meter
  • Compressor controls 2 – Attack, release, knee
  • Problems in compression
  • Stereo linking
  • Expansion and gating
  • Side chain
  • Mid-side (MS) compression
  • Transient shaping
  • Gating effects
  • Dynamic range control
  • Warmth in compression
  • Parallel compression

How you will learn in your course

The Audio Masterclass Music Production and Sound Engineering Course works by online distance learning. We have students in more than 120 countries all around the world. All you need to come on the course is a basic home studio setup and an internet connection, and of course a strong desire to produce recordings of fully professional quality in your own home studio.

With Audio Masterclass, you will learn basic studio techniques, mixing and creative recording. Following completion of your course, you can go on to enroll in our Professional Courses with topics such as Equalization, Compression, Reverb & Effects, Mixing and Mastering.

Tutorials and videos

Course instruction is through world-class online textbook materials, audio tutorials, and supplementary video materials where appropriate. We show you the important techniques of audio that professionals use every day, and you can use yourself in your own home studio. All of the course materials are available online, and also enhancement learning materials including videos shot at Abbey Road Studios 2 and 3. You can print, save or download all of your course materials as you wish to keep permanently.

Audio examples

Our tutorials and videos are supported by a wealth of audio examples, which are also downloadable. We recommend that you load these examples into your digital audio workstation so that you can listen to them in exactly the same way as when you’re recording yourself.

Many of the audio examples will show you what you should aim to achieve, whether the topic is EQ, compression, mixing, mastering etc. Others will show you how things can go wrong – and we’ll show you clearly the difference between good audio and bad, and explain the reasons why.

Practical projects

The best way to learn audio is to *do* audio – recording, editing, processing, mixing and mastering. And don’t forget the importance of close, attentive listening. The more you do it, the better you’ll get.

So the Audio Masterclass Music Production and Sound Engineering Course features a range of practical projects relating to the modules of the course. The practical projects will set you a task to complete, show you how to do it and point out what could go wrong. And when you have completed your project, you can compare your work with our examples – many of which are created by Audio Masterclass students.

Student advice team

All Audio Masterclass students have access to our Student Advice Team for the full duration of their enrollment. You can ask questions on any of the course topics and receive a personal response.


Because Audio Masterclass works by distance learning, you can learn entirely at your own pace. There is no set schedule and you can move quickly or slowly through the course as you wish and take breaks at any time.


Your Audio Masterclass enrollment will be valid for one full year, which is easily more than enough time to complete your course. You can save, print or download all of your course materials to keep permanently.

Your Audio Masterclass Certificate

Although no certificate can guarantee you a job in the audio or music industry, you will want something to commemorate your success on your Audio Masterclass course. Your course will lead to the award of your Audio Masterclass Certificate, which becomes available for download when you have completed 80% of your course or more.

Diploma upgrade option

As well as your Audio Masterclass certificate, it is also possible to achieve the Audio Masterclass Diploma. This is a traditional paper diploma with our signature, stamp, and seal, sent to you by mail anywhere in the world.

The Audio Masterclass Diploma is assessed through practical assignment projects, one in each module, that are submitted online for assessment.

When all of your practical assignment projects have been assessed to a satisfactory standard, your success on the course will be noted and your Audio Masterclass Diploma prepared and mailed to you.

Assessments of your practical assignment projects leading to your Audio Masterclass Diploma on successful completion of your course is a paid-for option, at $277 USD in addition to your regular course fee. You must be enrolled on an Audio Masterclass course before adding the Assessments and Diploma upgrade.

Our experience in audio education

Audio Masterclass has experience in audio education going back to 1986. We have been running online courses since 2001 which is longer than any other audio training provider on the web.


At Audio Masterclass we want to give you the fastest, most effective route towards a professional standard of work in your own home studio – a standard that is fully equal to professional studios and commercial releases.

We do this through effective, comprehensive instruction through tutorials and/or videos, audio examples, and practical projects that relate closely to real-world professional practice.

If you want to make fast progress, then Audio Masterclass is here to help.

What you will learn in your course

Your Audio Masterclass course includes a massive wealth of learning content, audio examples, and practical projects. And as well as all the knowledge, skills, and experience you will gain, your Audio Masterclass Certificate will be available for download on completion of your course. (Diploma upgrade also available.)

Compressor controls 1

Module content: A preliminary introduction to the controls of the compressor including threshold, ratio, gain make-up, and the gain reduction meter.

Project – Compression aural exercise 1: This assignment will ask you to match the compression settings of example audio segments, including threshold, ratio, and gain make-up parameters. The purpose is to help you develop an aural understanding of the effects of these controls.

Compressor controls 2

Module content: A further introduction into the controls of the compressor including attack, release, and knee.

Project – Compression aural exercise 2: This assignment will ask you to match the compression settings of example audio segments, including attack, release, and knee parameters. The purpose, once again, is to help you develop an aural understanding of the effects of these controls.

Problems in compression

Module content: Breathing and pumping are two undesirable side-effects of compression (although pumping can sometimes be used as a musical effect). Breathing occurs where the signal to be compressed has audible noise content. As the compressor brings down the peaks of the signal, it also changes the level of the noise. Breathing is the effect of the noise level going up and down. Pumping is similar to breathing but it refers to the signal itself and not noise. Pumping occurs in the gaps between loud sections of the signal when the signal rises in level until being compressed down again at the next peak.

Project – Investigation of breathing and pumping: Create examples of breathing and pumping that demonstrate both of these problems very clearly. Your demonstrations should be of sufficient clarity that a non-technical person would be able to hear and understand these issues with minimal explanation.

Stereo linking

Module content: It is important when compressing a stereo signal to activate the stereo link function. This ensures that the stereo image is stable and does not swing from side to side depending on which channel has the louder signal from moment to moment. Plug-in compressors often activate stereo linking automatically so it is important to achieve a full understanding of when stereo linking is and is not necessary.

Project – Investigation of stereo linking: This assignment provides a demonstration stereo file where stereo linking is essential if the audio is to be compressed. This assignment will ask you to demonstrate the issues of not stereo linking, and the solution of linking the compression in the two channels.

Expansion and gating

Module content: Where compression reduces the dynamic range of a signal, expansion increases it by attenuating low-level signals further, thus reducing noise and other low-level sound. Gating takes this a stage further and silences low-level signals completely. Compression and gating are often used together.

Project – Suppression of noise by expansion and gating: Noise is often most noticeably when an instrument is not playing. When the instrument is playing then the noise is masked. When it is not playing, expansion or gating can suppress any audible noise.

Side chain

Module content: The side chain input of a compressor allows the amount of compression to be controlled by another signal. This is useful for de-essing, for ducking music under speech, and for creating a pumping dance-floor mix.

Project – Creating a pumping effect using the side chain: Although this technique can be useful in any musical genre, it is most often found in EDM. The assignment will ask you to make the instruments of the mix dip down in level on every kick drum beat.

Mid-side (MS) compression

Module content: Mid-side compression can be used with a stereo hardware compressor to ensure that the stereo image is stable, and for interesting creative effects that would be difficult or impossible to achieve in any other way.

Project – Demonstration of mid-side compression: This assignment will ask you to process a stereo music signal so that it is in mid-side (MS) format. You will then compress the music for a special effect where the width of the stereo image varies in response to the beat of the music.

Transient shaping

Module content: Shaping the initial transient of an impulsive sound, such as a drum hit, bass guitar pluck, or guitar power chord, using compression and expansion or gating.

Project – Demonstration of transient shaping: Using the files snare-unprocessed.wav and kick-unprocessed.wav the assignment will ask you to make examples of transient shaping. Your examples will demonstrate shaping of both the initial transient of the sound and the decay.

Gating effects

Module content: Probably the best known gating effect is using a rhythmic signal routed to the key input to trigger a sustained sound, often distorted electric guitar chords, but can be any continuous signal. This creates a rhythmic pulse that is different in character than anything you can achieve with MIDI. The rhythmic pulse can be controlled and enhanced using the attack, hold, decay and range controls.

Project – Demonstration of gating effects: Using a sustained sound source and a rhythmic trigger signal routed to the key input, demonstrate a range of sound textures using the attack, hold, decay and range controls.

Dynamic range control

Module content: Controlling dynamic range is the original purpose of the compressor, although this course will show you many of its other uses. Dynamic range can be controlled by fader riding or automation, but this is a time-consuming process. The compressor can be set to control high-level signals and reduce the dynamic range so that everything instruments and vocals are at a more even level and are more pleasant to listen to and easier to mix.

Project – Controlling the dynamic range of a vocal: In this assignment you will be given a a recording of female vocal with an extremely wide dynamic range. The assignment will ask you to demonstrate reduction of the dynamic range using automation and a range of compression processes.

Warmth in compression

Module content: An instrument or vocal might not need compression due to an overly wide dynamic range, but it might still sound better after being processed, particularly through a vacuum tube compressor or digital emulation. ‘Warmth’ is a term we use for mild distortion. This module will explore the creation of warmth using the compressor.

Project – Investigation of warmth in compression: This assignment will ask you to find which of your plug-ins offers the greatest degree of warmth. It will then ask you to make a clear demonstration of before and after compression, showing that a vocal or instrument can be enhanced using compression even if the dynamic range is already well controlled.

Parallel compression

Module content: Standard compression reduces the dynamic range of a signal by lowering its high levels, bringing them closer to the low levels. Parallel compression, sometimes known as New York compression, is a technique whereby the high level signals are unaffected but the low level signals are brought up. Particularly in drum tracks, this can massively increased the sense of excitement and energy.

Project – Demonstration of parallel compression: In this assignment you will set up parallel compression in your digital audio workstation using a standard compression plug-in. You will then process a signal so that the low levels are brought up to achieve the sense of excitement and energy that is typical of the technique.

Sample page from the course manual...

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Sample page from the Audio Masterclass Professional Course in Compression

What our students say about their Audio Masterclass course…

About Course Designer David Mellor

Audio Masterclass Course Director David Mellor

David Mellor is the founder and Course Director Audio Masterclass, currently residing in the beautiful countryside of Oxfordshire in the United Kingdom. He has worked in audio education since 1986 in hands-on training, lectures and online. David Mellor holds the degree of B.Mus (Tonmeister) from the University of Surrey where he studied music, piano performance, acoustics, electronics, electro-acoustics and recording.

Live Sound and Recording Engineer

David Mellor worked as theatre sound engineer at London’s Royal Opera House, with responsibilities including sound design, front-of-house operation, stage monitoring and electronic design satisfying the likes of Luciano Pavarotti, Placido Domingo, Dame Kiri Te Kanawa and Karlheinz Stockhausen. David Mellor toured with the Royal Opera Company to the Dorothy Chandler Pavilion, Los Angeles, USA; the Odeon of Herod Atticus, Athens, Greece; the Sejong Center, Seoul, South Korea; the Bunka Kaikan, Tokyo, Japan.

Musician and Composer

Since 1985 David Mellor has had more than 1000 works published in the field of production music, including the Chappell and Carlin music libraries (now combined into Universal Publishing Production Music) and his own music library for which he has produced seventeen compact discs. Notable uses of his music include the BBC’s Horizon, Fahrenheit 911, and The Oprah Winfrey Show.

Writer and Educator

David Mellor has been actively involved in Audio Education since 1986, teaching students of City of Westminster College and Westminster University, and also returning to lecture at Surrey University. He has also written for magazines including Sound on Sound, Audio Media, Studio Sound, Home & Studio Recording, Performing Musician, Sound & Video Contractor, Recording Engineer & Producer. He has also written four books on audio and video technology. David Mellor now specializes in online audio education and has been Course Director of Audio Masterclass since 2001.