Audio Mastering – The Mysterious Post-Production Art Form

by Izotope on June 24, 2013 · 17 comments

in Fast Forward,Free Guides,Recording & Mastering,Uncategorized

Audio MasteringAudio mastering is the important final step in the recording process

This post on audio mastering is excerpted and adapted from Mastering with Ozone: 2013 Edition, a guide produced by our friends at iZotope. Reprinted with permission.

Audio mastering is often thought of as a mysterious art form, but its primary goal is fairly simple: to prepare a recording for distribution while ensuring it sounds better when it goes out than it did when it came in.

It all begins with the mix
You’ve just finished mixing what you think is a pretty good recording. The playing is good, the recording is clean, and the mix is decent. You export a file or burn it to a CD and proudly pop it in your audio player, yet when you hear it played next to a commercial track from your favorite artist, you think that somehow your recording is missing that sonic “X factor.” You can’t help but wonder, “What’s wrong with my recording?”

Diagnosing common problems
– It sounds small, and isn’t “loud” enough. Turning it up or mixing down at a higher level doesn’t solve the problem. Yes, that makes it sound louder, but doesn’t add the required impact or clarity.
– It sounds dull. Other recordings are warm and deep, yet bright and open all at the same time. You try boosting the EQ at high frequencies, but now your song just sounds harsh and noisy.
– The instruments and vocals sound thin and lack the sense of fullness that your favorite recordings have. You patch in a compressor and adjust some controls, and now the whole mix sounds squashed. The vocal might sound louder, but the cymbals have no dynamics. It’s fuller – and lifeless.
– The bass doesn’t have punch. You boost it with some low-end EQ, but now it just sounds louder and muddier, not punchier.
– You can hear all the instruments in your mix, and they all seem to have their own “place” in the stereo image, but the overall image sounds wrong. Other tracks have width and image that you just can’t seem to get from panning the individual tracks.
– You had reverb on the individual tracks, but it just sounds like a bunch of instruments in a bunch of different spaces. Your other CDs have a cohesive space that brings all the parts together. Not like rooms within a room, but a spaciousness that works across the entire mix.

What do I do now?
Audio mastering is a process that can take recordings to the next level. It might be the process that can address the problems listed above. What mastering SHOULDN’T be expected to do is completely reinvent the sound of your recording. Audio mastering is not a substitute for good mixing, or good arranging for that matter!

“Loud” records are a result of good writing/arranging/mixing AND mastering. They are made to sound GOOD and loud (if loud is what you are after) from the get-go, not just at the end. Once you have reached the final step of mixing with something that represents your best effort, then it’s time to dig in and see how much further mastering can get you toward the sound that you hear in your mind’s ear.

Audio mastering with iZotope

What is mastering?
Although there are many definitions of what mastering is, we’ll refer to mastering as the process of taking a mix and preparing it for distribution. In general, this involves the following steps and goals:

1) The sound of a record.
The goal of this step is to take a good mix (usually in the form of a stereo file) and put the final touches on it. This can involve adjusting levels and general sweetening of the mix. Think of it as the difference between a good-sounding mix and a professional-sounding master. This process can, when necessary, involve adding things such as broad equalization, compression, and limiting. This process is often actually referred to as premastering in the world of LP and CD replication, but we’re going to refer to it as mastering for simplicity.

2) Consistency across an album.
Consideration also has to be made for how the individual tracks of an album work together when played one after another. Is there a consistent sound? Are the levels matched? Does the collection have a common character, or at least play back evenly so that the listener doesn’t have to adjust the volume? This process is generally included in the previous step, with the additional evaluation of how individual tracks sound in sequence and in relation to each other. This doesn’t mean that you simply make one preset and use it on all your tracks so that they have a consistent sound. Instead, the goal is to reconcile the differences between tracks while maintaining (or even enhancing) the character of each of them, which will most likely mean different settings for different tracks.

3) Preparation for distribution
The final step usually involves preparing the song or sequence of songs for download, replication, and manufacturing. In the case of a CD, it can mean converting to 16 bit/44.1 kHz audio through resampling and/or dithering, and setting track indexes, track gaps, PQ codes, and other CD-specific markings. For web-centered distribution, you might need to adjust the levels to prepare for conversion to AAC, MP3, or hi-resolution files and include the required metadata.

Mastering effects
Mastering engineers typically work with a set of specific processors.
– Compressors, limiters, and expanders are used to adjust the dynamics of a mix. For adjusting the dynamics of specific frequencies or instruments (such as controlling bass or de-essing vocals) a multi-band dynamic processor might be required. A single band compressor simply applies any changes to the entire range of frequencies in the mix.
– Equalizers are used to shape the tonal balance.
– Reverb can add an overall sense of depth to the mix, in addition to the reverb that may have been applied to individual tracks.
– Stereo Imaging can adjust the perceived width and image of the sound field.

Mastering quick tips
1) Have someone else master your mixes for you.
In many project studios, the same person is often the performer, producer, mixer, and mastering engineer. Hiring a trusted mastering engineer is usually a good idea. Why? If you have the tendency to add too much bass or not enough top end due to your listening environment, those tendencies will be compounded in mastering. It’s also common for the mix engineer to be too close to his own music.: you’ll focus on some things other listeners won’t hear, and you’ll miss things that everyone else does hear. Having another set of ears mastering your project with monitors and an environment specifically dedicated to audio mastering can make a huge difference in your final product.

2) Take breaks and listen to other CDs in between sessions.
Refresh your ears in terms of what other stuff sounds like. Even seasoned pros who instinctively know what sound they’re working towards will take a moment to listen to a familiar recording and recalibrate themselves during a session.

3) Listen on other speakers and systems.
Burn a CD with a few different tracks and play it on your home stereo system, or drive around and listen to it in your car. Don’t obsess over the specific differences, but just remind yourself what other systems sound like.

4) Check how it sounds in mono.
This can’t be stressed enough. A good ratio between mono (correlated) and stereo (uncorrelated) information is very important in many contexts; broadcast, LP/vinyl cutting, and even MP3 creation. When you listen in mono and important instruments vanish, or if the level drops significantly, you might need to rethink what you are doing.

EQ quick tips
1) Too muddy? Try cutting between 100 to 300 Hz.
2) Too nasal-sounding? Try cutting between 250 to 1000 Hz.
3) Too harsh-sounding? This can be caused by frequencies in the range of 2000 to 3500 Hz. Try cutting this range a few dB. Hopefully, using a band or two in these regions will give you a better sounding midrange. A common technique is to start by boosting a band to dial in a region of the spectrum that contains too much energy, and then cutting it once you’ve centered on the problem area. You’ll get the most natural sound using relatively narrow bands when cutting, but when boosting, wide bands generally sound more musical (a Q less than 1.0).

Learn more – download the entire guide: Mastering with Ozone. Learn more about iZotope at

Learn How to Make 
a Great Master

Read More
Dithering – Adding “Good Noise” to Improve Your Home Recordings
Home Studio Posts – Recording Tips For Producers, Engineers, and Musicians
Your Home Studio Mix – Recording Tips For Better Results
Ear Fatigue and Mixing Music – Know the Signs, Avoid Mistakes
Mastering Gear Overview
Disc Makers SoundLab: What Is Mastering?

Look what I found on Disc Make's Echoes Blog!Share on Facebook397Tweet about this on Twitter61Share on Google+5Share on StumbleUpon214Email this to someoneShare on LinkedIn2Share on Reddit8Digg this

{ 4 trackbacks }

Audio Mastering – The Mysterious Post-Production Art FormUniqueSquared Pro Audio Blog
July 8, 2013 at 3:30 pm
An Inside Look at Audio Mastering Techniques | Cogswell College Blog
July 18, 2013 at 9:04 am
‘Tis The Season (To Sell CDs) | The Music Biz
November 13, 2013 at 3:31 pm
Why do you love vinyl records? |
June 30, 2014 at 10:07 pm

{ 13 comments… read them below or add one }

Donald W. Mohr July 8, 2013 at 9:55 am

“1) Have someone else master your mixes for you.”
This is all this article needs to say. As a mastering engineer, this cannot be stressed enough. A real Mastering Engineer has the kind of monitoring that project studios do not. Mastering, while typically the most expensive part per hour is the cheapest as the general consensus is about 1 day for a full LP. This is the part to not skimp on. Most MEs will give feedback about the mixes prior to mastering if requested. If you’re mixing yourself, this is an excellent opportunity to spot the problems and correct them prior to mastering where only certain kinds of problems can be corrected, most are just “kinda” masked.


John Lovrich July 17, 2013 at 6:33 am

Agreed, it’s really difficult to master things you’ve mixed, especially if you try to do it in the same space. I do both jobs and have different rooms for mixing and mastering, but it’s still tough, I can only imagine if I was the composer and performer as well . I find listening in the car, out in traffic, to be a great tool. If the melody and song hold together then, you can be pretty confident. Before I had the mastering room, I used to drive around, stopping to make notes on each tune. It worked, but it took 2 or 3 days to master a an album some times.

Multiband limiter plug-ins are a great tool to start with. Setting your ceiling on each band gives a fairly consistant spectral content tune to tune, while adjusting the gain in individual bands works like EQ. Change your crossover points to narrow in on problem areas.


mastering July 11, 2013 at 4:59 am

Managing the loudness of the track is the most intricate step in audio mastering,thus should be done with complete awareness and by a professional so that the song should sound more good after audio mastering.


Steve Roberts - Amongst Myselves July 16, 2013 at 7:35 pm

I do all my own mixing but I leave the mastering to a trusted Mastering Engineer, Neville Clark, to make my mixes sparkle to that final level. I highly recommend as Donald W. Mohr says – “Have someone else master your mixes for you”. It makes a great difference.


Glade Swope July 21, 2013 at 9:59 am

What if the mastering engineer says…
“I can’t help you. It’s too good!”


Anonymous July 16, 2013 at 10:09 pm

I always have my final mixes professionally mastered and always will. Unfortunately, the listening public at large won’t give two shits. We now live in a time where bands (not all, but most) write some of the worst songs, record them in the most non-produced way and people listen on the worst devices (cell phones,etc). Quality in all these areas has gone down the toilet. I will always strive for quality in all my projects, but I don’t put any faith at all in the public acceptance of it. To prove my point: play the Beach Boys – Pet Sounds, Todd Rundgrens – Something/Anything or Kansas – Leftoverture,etc to most people under 30 and they won’t get it. They want the anger and energy of heavy music with cookie monster vocals. The music scene is now for the lowest common denominator. Quality Music…RIP.


John Lovrich July 17, 2013 at 6:42 am

I pulled out Sticky Fingers on vinyl last week. Man, is that a great sounding record! The old heads knew. And The Pet Sounds is a great example of tunes that translate because they work in mono. Brian Wilson has been nearly deaf in his right ear for his entire career. He has to work a little harder so it sounds good to him, and we all get to enjoy a great record.


James July 18, 2013 at 6:49 am

You said it all brother


Ramiro Daza July 17, 2013 at 9:53 pm

I work on a Tascam neo 24. It has suggested mastering entries but I really do not notice a difference. Your articles are very helpful. I still struggle with finding a trusworthy person that could master some of my music in my area. Thank you for the info.


music programs for pc professional February 19, 2014 at 9:41 am

Excellent blog here! Also your website loads up fast! What web host are
you using? Can I get your affiliate link to your host?
I wish my website loaded up as fast as yours lol


vanboy March 28, 2014 at 6:53 pm

Thanks for that images. I say that a whole lot. Glad to see it together with the sunshine and clouds. Thanks. Edwina Brown


Cy Prian February 6, 2015 at 6:00 am

A nice intro guide to mastering engineering.


Raz Klinghoffer Mix Engineer March 24, 2015 at 6:23 am

Geat work! This is the type of info that should be shared across thhe internet.
Disgrace onn the search engines for not positioning this
submit higher! Come on over annd discuss with my web site .
Thanks =)


Leave a Comment

Previous post:

Next post: