FAQAnswers to frequently asked questions.

In short Audio mastering is the final preparation of a song or group of songs before they are released to the public. Check out our section on Mastering Services for a full description.

Stem mastering is the process of level balancing and editing multiple consolidated groups of instruments during the mastering process. It allows the engineer to get much deeper into a mix, and has the possibility to allow for more control over the final master. Read more about Stem Mastering.

Audio mastering is the art of giving your recording a cohesive and professional sound.  It should sound its best in a variety of different listening situations; such as on a home stereo, the radio or internet, in the car or through headphones. Naturally, it should be able to stand up in comparison with other productions.
The resulting final files must be technically perfect and free of artefacts or clippings. Aesthetic considerations aside,the main purpose of audio mastering is to ensure the most optimal sounding production as possible.

The Loudness War is a sonic “arms race” where every artist and label feel they need to crush their music onto CD at the highest possible level, for fear of not being “competitive” – and in the process removing all the contrast, all the light, shade and depth – ruining the sound.
In order to achieve these super-high levels, the music has to be squashed up against the digital maximum level “ceiling” – reducing the difference between the peak and average levels in the music. In the process, the contrast between loud and soft moments (often referred to as the dynamic range) is dramatically reduced.
Neptune Studios & Neptune Mastering gladly support all efforts to preserve audio integrity by providing high quality audio masters without resorting to losing dynamic range.

When preparing you mix for mastering you’ll want to do a few things. First off you want to make sure that each track, and the master bus peak levels are between -3db and -6db. This ensures that there is no clipping. The volume should sound low, we’ll raise it during the mastering process. Secondly, you’ll want to remove any processing such as limiters or compressors from the master bus. Third you will want to make sure that you submit a high resolution .wav or .aif file. We can master mp3’s however you will get a better final product when mastering from a high resolution file. You can read more about preparing your mix for mastering.

Yes & no. We can master from an mp3, however we recommend using .wav or .aif files as the resolution is usually much better. If you only have access to mp3 versions we can still achieve good results, but you will get a better final master using high quality .wav or .aif files.

Our standard turnaround time is based on studio workload, but generally speaking you can expect to have your songs back within 1-5 business days depending on how many songs needing to be grouped together.

Album sequencing involves putting a group of songs onto the final master cd, or master DDP file. During this process the engineer will add ISRC Information(if available), CD Text, as well as Album and Song Information. We will also set the spacing between songs and correct any final levels to make sure songs on an album flow together.

Recording studio design is an involved process that varies from project to project. With the ability to meet most any budget and location size, we offer from the basics of acoustics consulting & panel placement to full studio design & room equalisation.  Send us an email and we’ll work together to make your creative space as transparent as possible, getting you back to work on what’s important, the music.

Untreated rooms have an uneven frequency response, which means that any mixing decisions you make are being based on a sound that is ‘coloured’, because you can’t accurately hear what’s being played. In short, you can’t possibly tell how your mix will sound when played back anywhere else. It isn’t just an issue for mixing, though, because any recordings you make of acoustic instruments will bear all the hallmarks of the space in which you record them. That may be a good thing if the space in question is Ocean Way or SARM West, but probably preposterously bad if it’s your living room or bedroom. So, if you want your mixes to transfer well, and your recordings to be free of room ‘honk’, you need to pay attention to the acoustic properties of your environment – no matter how good the gear you’re using.



The final process in preparing an album or EP for release is cd mastering. This is crucial step for a number of reasons. The goal of mastering is to is to enhance the overall sonic clarity of a song as well as make sure that individual songs are level balanced to maintain a consistent sound and volume level. In addition correct mastering will ensure that your songs are set to the correct frequencies and levels for digital distribution and radio play. In the simplest terms cd mastering is what makes a group of songs sound like a commercial released record. For clients who do not need a full album or EP mastered we also offer our standard per song online mastering service.


Our experienced mastering engineer uses specially designed equipment, software, and speakers to access and correct problems within each song. During the mastering process there are many adjustments that are made depending on the musical genre, instruments, and mixed levels. Some of the functions the mastering engineer will provide include:

  • Adjusting Individual Frequencies
  • Balancing Left and Right Stereo Channels
  • Equalising The Sound of Each Track
  • Compressing and Limiting the Overall Sound Level
  • Automating Compression and/or Equalisation
  • Adding Dithering
  • Add or Correct Improper Fades
  • Set Spacing Between Track
  • Using Noise Reduction and Sound Restoration if Needed
  • Adding ISRC Codes for Distribution Rights
  • Adding CD-Text Information (Artist, Title, Track Names, etc)
  • Create DDP, BIN, or CUE Files for CD Replication or Duplication
  • Creation of a Master Disk


Neptune Mastering clients use our online system to upload and manage their projects. In addition we use the same system to upload finished masters and keep track of messages and song / album details.

Stem MasteringWhat is it?


In addition to our standard mastering service, we also offer stem mastering for clients who want our mastering engineer to have the most control during the mastering process. For the majority of projects standard stereo mastering will provide excellent results, however for artists who prefer to give our engineers the most possible control over their mix we also offer stem mastering. Mastering from stems allows us to dive in deeper to the mix and more finely adjust frequencies and levels. It also allows us more control to correct problems in the mix that might otherwise be impossible with a single stereo file.


When mastering from stems you will submit multiple stereo tracks that have consolidated instruments. For example an artist might submit 4 stereo wav files ( One containing all lead synths/guitars, one with lead vocals, one with drums, and one with background vocals, etc). Our engineer would then work with each stem to set frequencies, adjust levels, and correct any imperfections. When he has finished the stems are combined and the final song is then mastered. Since we have access to separated groups of instruments there are more options for the engineer to make fine adjustments and correct problems.


Preparing a mix for stem mastering involves grouping your instruments into individual stems. We accept up to 8 stems per song, and as a general rule you want to group similar instruments together. An example set of stems would be: Percussion, lead vocals, backup vocals, rhythm guitars, lead guitar, kick and bass. The stems you submit can be separated any way that will give our engineer the best options to work with for your project. As with all mastering projects you should leave -6db of headroom and remove any master bus processing from each stem. Stems should all be the exact same length and start and stop at the same time (this is crucial so the tracks line up when they are mixed together.)

Pre-Mastering TipsBefore you send your music.


There are a number of audio mastering tips that will help you prepare your mixes before working with a mastering studio. It’s important to know how to prepare and submit you mixes so you can get the best sound for your songs. The mastering engineer wants to start with a clean slate, primarily on the master bus and will need to have the proper file type and format to get the most from your music.


As you go through your mix eliminate any noise or pops that may be in each track. Use fades as necessary to cut out any spots that may just be containing recorded noise. If this is done in the mix stage within each track it will keep the overall noise level down when the mastering engineer begins to equalise and compresses the mix.


Overusing processors especially dynamic processors (compressors) on the master bus can destroy a mix and make it difficult, if not impossible for the mastering engineer to make a great master. Unless there’s a specific sound of a master bus processor desired for the mix, it’s best to keep the master buss free of outboard processing or plugins. If master bus processing is used make sure to notify the mastering engineer of its type and settings.


The loudest part in a mix should peak at no more that -6db on the master bus.
There should never be a limiter set on the master bus. Final dynamic control and level should be left to the mastering engineer. This allows the engineer to create the proper dynamic level for radio play, CD, or mp3 duplication.


  • Lossless file: File that contains the exact data to be reconstructed and retains audio quality.
  • Lossy file: File that contains an approximation of the data to be reconstructed and degrades audio quality.
  • Lossy file formats should never be used when submitting an audio file for mastering.

The two most popular file types for mastering are: .WAV and .AIFF. Both of these file types are lossless (non-compresses/converted), and either file type is excellent for a mastering engineer to work with. AIFF files are normally used on Mac systems while WAV files are traditionally PC. Make sure your mastering studio is able to work with the format you have.

Additional to using .WAV or .AIFF file types. When submitting a mix for mastering. The file should be kept in the same resolution as it was mixed in (no down conversions).
For Example: A song mixed at 24bit 96kHz should be submitted as a 24bit 96kHz file (.WAV or .AIFF).


Submitting any previously done mixes or masters of the song/s to be worked on, along with a few different reference songs that have a similar sound desired is excellent for giving the mastering engineer an idea of your musical vision. This could be a reference to bands/releases that inspire you, or who have a similar sound you like.


Mastering from stems is becoming a more common practice. This is where the mix is consolidated into a number of stereo stems (subgroups) to be submitted individually. We accept up to 8 stems per song. For example you might have different tracks for Kick Drum, Drums, Bass, Keys, Synths, Effects, and Vocals. This gives the mastering engineer excellent control over the mix and master, allowing for the absolute best sound possible. However, it’s a substantially more involved process. If a mix from stems is desired, following the same steps listed above is best for each stem.

Note: When submitting stems, each file must start at the same time in the song even if each of the stems’ audio regions start at different times.