What is stem mastering?
Stem mastering is the process of mastering a song using a group of stereo stems, i.e. groups of similar-sounding instruments, instead of an individual stereo audio file (as per stereo mastering). Though they are different techniques, both mastering approaches have the same end goal: to enhance the song and prepare it for distribution.
When to consider stem mastering
Stem mastering can be beneficial when you don’t feel like your mix is quite where it needs to be, and you’d like your mastering engineer to be involved in the production process. By having stems created, you give your mastering engineer a little more freedom to make adjustments in order to get a more complete final product in your master. For example, if you think the mix is 90% there, but can’t quite get the right low-end balance compared to current releases in the genre, then this approach would be a great option to address that issue.
You may have also hit a time limit for your mixing budget and require stems to be created to finish things in the mastering phase. Mixing can be a very tedious and time-consuming process depending on how many tracks you’re working with, how much processing needs to be applied to each track, and the overall feel you want out of your mix.
Stems simplify the process by dividing the audio into groups of instruments that have already been mixed to prepare for the mastering treatment. When you have stems created, it may be easier to have someone else mix your project quickly later on, but it may also provide your mastering engineer with a better overall sense of the tone you’re after.
The downsides of stem mastering
The stem approach to mastering can give your mastering engineer a little more control, but it isn’t without its pitfalls. One of the biggest issues with stem mastering is that it takes more time.
Because using stems to master a track is similar to mixing, your mastering engineer may need to spend extra time adjusting each stem. Depending on how many stems you have, this can prolong the final master.
Changes to stem levels can affect mastering processes
Your mastering project may also take longer when using stems because added attention is required to balance. When your mastering engineer applies dynamics to a complete mix, the effect applies evenly.
If your stem levels need to be adjusted after effects have been applied, your engineer will need to go back and make adjustments to any applied effects as the entire balance of the master can get thrown off. In addition, if processing has been applied to each stem during the mixing phase, this can cause unwanted interactions during mastering.
For example, if you’ve compressed your drum tracks when creating a stem for the drum group, your mastering engineer may need to work harder to avoid unwanted interactions when applying master compression across your entire mix.
Your master may turn into a mixing project
In keeping with the above, you may also run into a situation where your mastering engineer may view your project as a mixing project in addition to a mastering project. Remember that a mastering engineer’s job is to take the final mix and enhance it, not to mix your tracks. At a certain point, having a bunch of stems becomes too similar to mixing, and you’ll likely be charged accordingly.
Stems won't make up for a bad mix
It’s also important to remember that using stems won’t make up for a bad recording or a bad mix. If your audio is recorded poorly or your mix is problematic, your stems will reflect this and can negatively affect your master.
This applies to any mastering project. Your recording needs to be done properly, and your tracks need to be mixed before a mastering engineer can help. If you’re lacking in either of these two areas, there isn’t much point to mastering your music until you can resolve these issues.
Communicate with your mastering engineer
At the end of the day, most engineers will be happy to accommodate you with the approach that you wish to take, but don’t wait until the last minute to mention that you’ll be working with stems instead of a final stereo mix file. This can inflate the time it takes to complete the project, and it will likely cost more in the end. Additionally, you may not get the result you’re after without additional hassles if you don’t speak up.
While stem mastering is only beneficial in certain circumstances, don’t be afraid to discuss this option with your engineer. They will be able to evaluate your project, provide you with guidance and help you decide which approach will deliver the best results.This applies to any mastering project. Your recording needs to be done properly, and your tracks need to be mixed before a mastering engineer can help. If you’re lacking in either of these two areas, there isn’t much point to mastering your music until you can resolve these issues.