While CD mastering involves audio mastering, more goes into delivering a final product than when you are simply affecting the audio itself. In this article we’re going to talk about the difference between CD mastering and audio mastering.
First let’s discuss what is involved in audio mastering. This is what most people think of when they think of mastering as it involves purely sculpting and shaping the audio itself. This is accomplished through use of plugins and effects which can be loaded into your digital audio workstation, plugins such as equalization, limiters, and compression.
Equalization is the most commonly used effect in mastering if necessary because it is used to dissect the audio in different ranges from low to high to affect that section’s presence in the greater mix to achieve different kinds of results. Boosting the low end is very effective when a recording is lacking in a bass sound and you want to compensate for that void. A good example would be on a recorded acoustic guitar if perhaps it was recorded improperly and too far away from the cutaway sound hole in the instrument.
Without this natural bass, you can compensate by augmenting the low end via the EQ, thereby giving the song a thicker presence in the overall mix. On the other end of the spectrum you can add to the high end using EQ to compensate for an abundance of high end or you can alternatively diminish the presence of the low end using the EQ. Boosting the high end can also give a sharper sound to individual tracks in a mix or to the entire song in the mastering stage.
Compressors and limiters are also effective for ensuring that your entire record is at a similar volume with itself. Different songs are likely to be recorded in different environments with different instruments and settings whether it’s intentional or not, so it’s likely that the volumes of those various songs are not in unity with one another. Therefore, even if you’re not performing CD mastering, you’ll want to place all of your final mix tracks on one file in your DAW and consequently use these plugins to ensure that they’re all harmonious with one another level wise.
You can stop right there with normal mastering but when it comes to CD mastering you’re going to go that extra step and actually sequence the record and add data which will be written to the CD itself when replicated. Sequencing refers to creating a table of contents for the record and establishing the flow and breaks between tracks which can be according to the artist’s specifications and data is additionally written as a final step to add information like artist and song info to each track.
When CD mastering, it’s also important that you add that 2 second gap if your software does not do this for you automatically so that it complies with Red Book standards and there will be no playing issues on any CD players. Overall, the ultimate goal is getting a perfect image file, DDP file, or hard disk to be sent for replication so that there are no costly errors which are discovered only after replication has been performed at the plant.