Audio Mastering Services
By Chase Jentz
It has many names, mastering, audio mastering, audio mastering services, CD mastering… the list goes on, but, what is it? In this article I will explain the key elements of audio mastering and what to expect from a professional mastering session.
Let’s start with a basic definition of mastering – the final step in the recording process, where songs are optimized for level, EQ, clarity, low end punch and overall consistency.
That said, ‘mastering’ is a very broad term and pertains to many non-audio aspects of a recording as well, which I will cover in more detail later. To me, a good mastering engineer should start by simply listening to the music and trying to get a feel for what the artist or musicians are conveying, then determine which processes may improve the recording, and help the songs become a more cohesive album, so as to better communicate the record to the listener. Never the less, it is also a good engineer’s job to know when not to over process recordings, with things like EQ and compression, if it is uncalled for.
Professional audio mastering services should begin with the mastering engineer’s ears, a state of the art monitoring system, and an acoustically tuned room that allows the engineer to hear all the nuances of the recording. From there it depends on each individual session, but an engineer may do things like make adjustments to the relationships between highs, mids and lows, using tools such as an EQ, harmonic exciter, or multiband compressor, to name a few.
Compression can also be used to make levels consistent from song to song, aiding in the final product’s continuity, while limiting is a good tool for bringing up the overall level of the entire record to sound as loud as a ‘store bought CD’. Many other tools may also be used, such as expansion instead of compression, stereo imaging to add some depth, or mid/side processing to really surgically EQ specific aspects of the recording. Some more conventional tools include analog tape machines, analog amps, tube preamps, compressors and EQs.
Once all of the sound issues have been taken care of, the mastering engineer will sequence the tracks in the final order of how they will appear on the record. The track sequence is quite a bit more involved than just click, drag and burn. Usually, the engineer will adjust the individual time between tracks to help give the final record a nice flow from song to song. This is also the stage where fade ins and fade outs are done, as well as any additional track clean up. Mastering is really subjective, and once again, is different for each project.
A knowledgeable mastering engineer also deals with many aspects of a recording which are not audio related yet are still part of the audio mastering services. Often referred to as ‘Red Book Specifications’ the engineer will embed certain elements or properties to the master CD that are useful in the CD duplication process. Among these elements are ISRC codes, which are used by radio stations to track airplay and pay royalties, as well as sub-codes that allow CD players to display the name of the artist and song while the CD is playing. The engineer will also generate a PQ sheet: a page of codes showing the start and finish times for each track, as well as the amount of space between the tracks, and additional information useful to the company duplicating the record.
Helpful mixing tips
Try not to over EQ your mix. If you attempt to make it sound like a store bought CD right out of the mixing room, it makes the mastering session that much harder. It's part of the mastering engineer's job to make sure the overall EQ is fat, punchy and brilliant. Just concentrate on delivering a good clean mix, even if it sounds a little dull to you.
Also, never put compression or EQ on the master fader. When your songs go to mastering, you want the full dynamic and tone of your mix to be available to the mastering engineer. Don't try to make your final mix as loud as you can possibly get it. Never go into the red or clip the master fader, as this will usually cause your mix to distort. Make your final mix output peak between -3 and -6 dbfs, which will allow plenty of headroom for the mastering process.
After your mix is done, take some time away from it to let your ears rest. You'll probably find some subtle little things you want to tweak that may have been overlooked due to ear burn. Then, play your mixes on several different stereo systems to determine how consistent they are. This will usually expose some undesirable frequencies that aren't as noticeable in your main mixing room. Once your mixes are as close to “finished” as you can get them, send them off to be mastered.
On A Personal Note
As a musician for over 24 years, I realize how important it is to make sure your music is in the hands of the right person. Our songs are our feelings, life experiences, hardships and dreams. The last thing we want is some mastering engineer just going through the motions after the months of hard work it took to finish a record. Over the years, my passion for creating music has been equaled by my love of being in the studio, working with other musicians, and making their records sound the absolute best that they can. Learn more about Chase Jentz.
Return from Audio Mastering Services to Studio 66 home page