Preparing for Audio Mastering
BY DR. TOBY MOUNTAIN
1. Why do you need Audio Mastering? 5. Backups
2. Planning - Time and Money 6. Preparing for the Mastering Session
3. Formats  7. Can You Expect from Mastering?
4. Mixing Tips 8. What Miracles can You Hope for?

Studio A View

The mastering environment should ideally be in a relaxed "non-studio" setting.

 1. Why do you need Audio Mastering?

It's a good question, when you consider all of the inexpensive boxes and plugins out there that promise amazing results with very little effort or knowledge. Just plug it in and out comes million dollar audio! Or so the mantra goes.

It doesn't quite work that way, especially when you consider that good sound, just like your music, is an artistic endeavor. It takes a real mastering engineer with good ears to objectively evaluate your project, and let you know what needs fixing. A box or a software plugin just can't replace the human element with that amount of close attention to detail.

There are other reasons. When you finish mixing, the first order of business is to "remove yourself" from a studio setting and start hearing your project in the real world. Professional mastering gives you that opportunity - in a place where you can monitor your project in a high quality, but "real" environment, similar to your most critical listener.

Finally, the mastering stage allows you to make final aesthetic corrections before you commit to replication. Important details like sequencing, fades, and even song structure can be positively improved at a mastering session. These may be things you may not have even thought of! By giving yourself that one last opportunity to proof your mixes, you will come away with a more refined product.

2. Planning-Time and Money
Studio A View
Many projects exhaust their budget by the time they get to mastering. But it's a shame to exclude a process that can exponentially improve your project for just $800 or less. So try to fit it into your time and money budget.

The cost of mastering will depend on both the length of your project and the consistency of the mixes. We can give you an accurate estimate for everything, including reference discs, shipping and archiving.
Do not expect to leave with a finished master on the day of your session. Allow yourself time for revisions and "touch-ups." After each revision cycle you will receive a new reference disc to evaluate. This whole process may take 1-2 weeks.

Artwork will most likely cause any delay in your production process, so start designing your artwork before your mastering session. The CD manufacturer needs finished artwork (computer files) at the same time that your audio master is delivered.

Here is a summary of these guidelines:
1. Budget and Time for Mastering - between $500 - $1,000 / 1-2 weeks
2. Time for Art work (label, CD booklet design) / 3-4 weeks
5. Multimedia assets for Enhanced CD or DVD-Video must be coordinated in advance.

3. Which Format? Bit Rate? Sampling Rate?
Analog or Digital
 A good mastering facility can handle any format.

It's more important that you choose a format that complements your equipment and will optimize your mixes. Try to avoid sampling rate and format conversions during the tracking and mixing process. There are some guidelines that you can follow.

1. It is very important that you mix to 24 bit rather than 16 bit. This will give you an audible quality advantage.
2. Sampling rate is much less important. We get mixes anywhere from 44.1 to 192 kHz and the higher rates offer only a very subtle improvement.
3. Your mixes can be delivered to us on a CD-R, DVD-R, a hard drive, or uploaded to our ftp site.
4. For those of you who are contemplating mixing to analog, there are some important guidelines and comparisons that will help you get the best results. Don't be afraid to insist upon these things!
Recommended Formats preferrred formats in bold
Analog Digital

Analog

Digital
recording device:  
high quality tape machine high quality outboard A/D converter
format:  
1/2" or 1/4" 24 bit computer files: .WAV, .AIFF, or .sd2
  16 bit Audio CD-R
speed/sampling rate:  
30 IPS NNR, 15 IPS NNR, Dolby SR 44.1, 48.0, 88.2, 96, or 192 kHz (use internal clock of A/D)
calibration tones:  
Cal tones:80-100 / 1kHz /10kHz /15kHz No tones needed
pros:  
rich, coherent sound, condusive to pop music excellent detail & clarity, inexpensive
cons:  
expensive in time and tape costs sometimes brittle, edgy, & less cohesive

4. Mixing Tips
It may seem out of line for a mastering facility to make recomendations on mixing. But we have found over the years that a few guidelines on protocol can help save a lot of time, money and give you better results. Here's our list of helpful hints:
1. Do several mixes of each song, if there are artistic issues:voc up/down, more less reverb, etc. take advantage of automation. A mastering engineer can easily piece together several mixes to create a nice composite.
2. Keep the levels healthy, but not peaking. 2-3 dB below peak gives the mastering engineer headroom to work with.
3. Use compression sparingly - only on individual tracks, not on the overall stereo bus mix!
4. Leave fades alone. Fades can be better executed and will have better fidelity in the mastering process.
5. Log all mixes accurately with complete descriptions! For digital file names: ID all mixes with dates, but don't make your file names rediculously long! Analog: leader all mixes.
6. Take copies of mixes home - compare to roughs for "feel" and spontaneity.
7. Avoid doing any post production tampering with the mixes, especially with an inexpensive PC audio program or mixer!
8. Use digital dubs or safeties to experiment with sequencing, segues, etc.
9. Take extensive notes on the things that you feel need fixing in the mastering.
 
5. Backups
Redundancy is very important when you are mixing. Try to mix to at least two different formats simultaneously.
Master Mix Backup
1/2" Analog 24 bit Pro Tools bounce
24 bit Pro Tools bounce 16 bit Audio CD-R
  16 CD-R or 24 bit Alesis CD-R
Make sure your mixing engineer is backing everything up to another hard drive at the end of the day.

6. Preparing for the Mastering Session
Analog or Digital
 It's always advantagous to send your mixes to us ahead of time. That way we can load the audio in advance and be ready to go to work when you walk in the door. Have your mixing engineer copy the files onto CD-R, DVD-R or a hard disk and send them to us.
Our address: 2 Hidden Meadow Lane, Southboro, MA 01772
Or contact us if you want to use our ftp server.
On the day of the mastering session please bring the following:
1. All backup files of your mixes, as well as a 16 bit audio CD-R of your project. We will use it to compare to the work we do.
2. A written list of the sequence of tracks.
3. Any notes about specific issues regarding the sound.
4. A few of your favorite CDs by other artists that may be similar in style and instrumentation.

7. What Can You Expect from Professional Mastering?
1. A professional environment with extensive experience and track record. SonicSystem meters
2. The ability to handle just about any format you may have.
3. The ability to put together any sequence or combination of sounds you desire through editing control and accuracy not available to most multitrack or home project studios.
4. Consistency in the overall sound, ie. from track to track, allowing the listener to focus on the music and not on "sonic distractions."
5. A fully verified and approved master acceptable for production at a CD plant.
 
8. What Miracles Can You Hope for?
1. Extensive remedial EQ and/or compression. Rescue of a poorly mixed track.
2. Adjustments of internal levels.
3. Denoising, declicking, removal of cosmetic noises, ie. mouth clicks, acoustic clicks.
4.Sonic repairs of dropouts, noisy endings, etc. with patching, reverb, wave cycling, interpolation.
5. Your CD will be louder than everyone else's! (Just Kidding!)
Many thanks to the staff at NDR, Anne Shepard, Laurie Flannery, for their assistance in writing this article.