Whenever you’re mastering for a physical release, there are additional considerations to be made. For instance, with vinyl you need to account for the limitations of the medium such as reduced dynamic range and have to be more hyper aware of the lower and higher ends of the audio frequency spectrum.
But in this article we’ll talk about how CD mastering differs from digital mastering, or in other words mastering for a purely digital format.
CD mastering and digital mastering are more similar than most would think. In fact the only difference lies in the final steps, after the audio has been processed. That means that you’re putting together the exact same master in terms of the sound itself for both the CD and digital release. Whatever compression you add, whatever EQ you use to sculpt, whatever limiting you apply, you’re going to be using the same audio for both mediums.
Where the two begin to diverge again is in the later stages where you’re prepping the album for the physical release of the compact disc. When you’ve finished applying your audio processing and gotten the actual tone of the audio to where you want it, that audio is more or less ready to be rendered and dithered down to 16bit audio WAVEs or MP3’s (Online-Audio-Mastering.com engineers provide every client with both the finished high quality WAVEs as well as MP3s for their convenience. Why not grab a free test sample master right now and get a high quality mastered WAVE and mp3 of your song of choice today, no charge?).
There’s a lot more to account for with a physical compact disc release. You still obviously dither the audio down to 16bit but you need to create a file set, typically a DDP, of that album which reflects all of the pertinent information to send to the replication plant, basically ensuring that it’s set to be pressed en masse and without issue.
The pertinent information includes artist and song ID information including ISRC and UPC codes and very importantly the Redbook-friendly sequencing information in the form of a PQ sheet to include with the DDP to send to the replication plant. This tells the engineers at the replication plant exactly when each song begins and ends down to the hundredth of a second on the overall album. This is something which the mastering engineer works with the artist to determine.
Some artists don’t necessarily care about sequencing beyond the tracklisting itself and aren’t nearly as concerned with the gap between tracks beyond whatever is typical. Other artists are more demanding, however, and are may have specific orders like time between tracks or will even want fade outs or overlaps between when one track ends and another begins on the album to give it more of a continuous feel.
It’s ultimately the audio mastering engineer’s job to ensure that all of this information is in order and will be written to the master CD and subsequently the copies without issue, otherwise it could add up to a costly mistake if an issue goes unnoticed through to the replication stage.
Interested in a CD master, just digital, or even vinyl? Our engineers at Online-Audio-Mastering.com have years of experience in mastering for all different formats, so give us a free test drive, no risk, no cost, and no obligation, by clicking the link at the top of this page for a sample master of one of your own songs.