Mystery Room Mastering Information

UPDATED: 07/05/2019

Before the Mastering Session

There are two ways to get a project started. The easiest way is using the Cost Calculator on the Mystery Room Mastering website to enter the variables and details of the project, as well as upload the audio files. This will also give you an accurate estimate on the cost of your project. If other arrangements have been made, send an email with a link to the audio files, and include a typed note with the following info:

  • artist/band name exactly as it should appear in the CD-Text and/or metadata (info embedded into the CD master and/or mp3 and WAV files)
  • album title or release/project name (please don’t use ALL CAPS unless it’s truly part of the name/title)
  • song order/track listing (Please note where side A and B are split for vinyl releases). Make sure the spelling and capitalizations are exactly as they should appear. Also, make a note if there are any mix files that may have an old or different name rather than the official name to avoid confusion and help us identify them.
  • format(s) in which the project is being released (CD, vinyl, cassette, online/digital distribution)
  • ISRC codes are optional and can be provided for a small fee if you do not have your own. You will need them for online distribution. If you don’t have them, online distribution services will provide them for you, but having them generated ahead of time ensures the codes are properly applied to all master formats rendered by Mystery Room Mastering including the CD master if applicable. It’s not possible to retroactively add ISRC codes to a CD master after CD production has started.
  • If you’d like the album cover art embedded into an mp3 version of your project, please email a .jpg or .png file along with the audio files, or as soon as it’s available. WAV files can also support artwork, but very few apps can display it. CD masters cannot contain artwork.

Since the songs are being submitted as data files from you or the mix engineer, they are not sequenced in any order other than alphabetical (or numerical if they are named with an 01, 02 etc. at the start). Be sure to provide the song order in the web form or a separate note to be sure. Do not assume that your mix engineer will relay this info to us for mastering.

If you have a stylistic mastering preference, make it known before mastering begins. Some want a master that is loud and competitive with other modern material, while some prefer a more natural sound while preserving the dynamics, transient detail, clarity, and sacrificing some overall loudness. Please let it be known if you have a preference either way. Feel free to mention a few tracks in the notes section of the project form that you like in terms of overall loudness and tonal balance (EQ).

Remember that louder is not always better and every mix has what’s called “loudness potential”, meaning depending on the nature of the performance, recording, and mixing, something can be measurably loud but not have a high perceived loudness. More on that in THIS ARTICLE.

As for any noises, count-ins, or talking before and/or after any songs, make note if any of those sounds should stay in or be removed. Feel free to include any notes about song-to-song transitions and general spacing between the songs. It may be helpful to create and send one continuous file of the album to demonstrate the transitions if precise transitions are desired between certain songs. The reference file for transitions can be an mp3 for ease of sending as it will only be used as a template or map if you will, when sequencing your master. The audio itself will not be used.

If you’d like any equipment (or other) noise/hiss to be removed or reduced during intros, outros, or other quiet parts where any noise/hiss is usually more noticeable, please be sure to include a sample (at least 1 second) of ONLY the noise/hiss (with no music or other sounds) before or after the song.

Generally speaking, any hiss that is already present to some degree within a song can appear louder after it’s mastered unless some noise reduction is done, so if you think any noise or hiss may be a problem after mastering, be sure to include a sample of the noise or hiss for each song in question so an attempt can be made to reduce the noise. Without a clear noise/hiss fingerprint, it’s much harder to do any useful noise reduction if at all. So, it’s best to leave a few seconds of noise floor and/or room tone before and/or after the songs incase any noise reduction needs to be done.

It is strongly recommended to very carefully triple check the final mixes for any stray noises, pops, and clicks that may become more noticeable after mastering. Cleaning up individual tracks when they’re not in use within your mixing sessions can help prevent the buildup or exaggeration of unwanted noises after mastering.

It’s also strongly recommended to listen to the actual mix files you’ll send in for mastering because it’s not uncommon for a glitch or anomaly to occur when creating the final stereo mix file for mastering that wasn’t present on playback in the DAW, or on previous mix versions.

Submitting new mixes, or remixes after the initial mastering is done is subject to further billing, but the basic mastering rate includes unlimited revisions on the files you initially submit for mastering until you are satisfied with the results. Even the smallest mix change can require a lot of work to process and remaster the new mix through the analog equipment and other various processes. This is why it’s important to be sure that there are no errors with the files you are submitting that can be easily corrected before the mastering begins.

Preferred Audio File Types

  • Your final mix files can be stereo (interleaved) .wav or .aif files
  • 32-bit floating point (or 64-bit floating point) audio files are strongly preferred. 24-bit files are OK, and 16-bit files can sometimes be OK only when 32-bit float (or 24-bit) files are absolutely unavailable.
    ***A note to mix engineers and those mixing their own material “in the box” or fully in a DAW: Even though your recording settings in your DAW session my be set to 24-bit, if you’re using a modern DAW, it likely processes audio at 32-bit (or 64-bit) floating point. So, it’s important to either save your mixes as floating point, or to dither to 24-bit. I personally think saving as 32-bit float with no dithering is the best option. Feel free to email me with questions about this. If you’re unsure what bit-depth your DAW is processing audio at, you can use this free plugin to analyze your mixing session. Put it in the very last insert slot of your master fader and use the bit-depth meter within the plugin to see if your audio is higher than 24-bit. With most modern DAWs, it probably will be unless you’re specifically dithering to 24-bit on the master fader.

Saving a mix file as 24-bit from a DAW that operates at 32-bit floating point (or higher) means some of the bits are being truncated (or lost) which is not ideal. Saving as 32-bit floating also helps preserve any peak information that may have gone over 0dB by accident.

For more info about how much headroom to leave on your mix files, see THIS ARTICLE.

The preferred sample rate is whatever the original recording and/or mix session is at. Basically, there is no need to up-sample files to a higher sample rate once they’re printed. Don’t change the sample rate of your files before sending.

  • Don’t convert mp3s to WAV for mastering. Use true WAV files.
  • Please be sure that the mix files have reasonable headroom to work with and are not already peak-limited for the sake of loudness. It’s hard and sometimes impossible to do anything useful (sonically) to mixes that already have a high RMS (average volume) level and consistently clip or hit 0dBFS.
  • Please don’t send mix files that have already been “pre-mastered”, normalized, or made extremely loud using digital processing. It’s understood that in some cases, certain plug-ins on the master fader/buss can be very important to the sound, but if you are adding an L2 Limiter (or something similar) simply for the sake of loudness, it’s preferred to have that type of processing removed before making the final mix files for mastering.
  • The final master can be as loud as you’d like, but it’s hard to do a quality mastering job when the unmastered mix files already have peak-limiting and/or clipping applied.
  • If you are or have been mixing with a peak-limiter and/or other mastering type processing on the master fader, it can be very helpful to send a version of each mix with and without that processing so we know what you’ve been used to hearing, but also have a better starting point for the actual mastering work.
  • This only refers to processing on the master fader, mix file, or overall mix. Compression on individual tracks or instruments within the mix is certainly ok. As long as the overall mix level/DAW output is not hitting or exceeding 0dBFS, and there is no limiting on the master fader or anything else preventing the levels from exceeding 0dBFS when they otherwise would, the levels should be acceptable for mastering.

It’s becoming more common for mix engineers to show clients working mixes with some “faux-mastering” added for loudness, but ideally the mix engineer will remove that “faux-mastering” and create a 32-bit float mix file without any limiting and loudness processing for the actual mastering session. Feel free to send the “faux-mastered” versions as a reference point but I normally prefer to work with versions that have more natural headroom.

Although it might seem simple, one can’t simply turn down a mix file that is already too loud because in most cases, severe sonic compression (and damage) has already been done to achieve that loudness. This can only be undone from the mixing source by removing limiting and other techniques used to achieve loudness.

If you feel that your mixes won’t be the same without a particular plug-in on the master fader, feel free to send one song as a sample to see if it’s something that can be worked with, or send both your processed version and a version with no processing on the master fader to show what you’re shooting for.

Delivering Your Mixes for Mastering

When using the cost calculator on the website, you will eventually be taken to a page that allows you to upload unmastered files directly to a secure place. Please upload just one .zip file containing all the files and name it clearly with the artist/project name so it can be identified easily. The upload page can also be found HERE.

If you’d rather share a direct link or folder, Dropbox is the other preferred way to receive your mix files via the Internet. If you don’t have a Dropbox account you can go to and sign up for a free 2.5 GB account which should be enough space to upload your high resolution mix files for a full album. Please send a direct link to the files (not a shared folder) to: or you can include your own link to the mix files in the project form that will be filled out. Please avoid Google Drive links if possible.

Direct links from other file sharing sites are ok but please avoid using file sharing services that require signing in or creating an account to retrieve the files. Also, avoid sites that require downloading each file one at a time. Making a single zip file of all your mixes to avoid any errors or issues, is best practice, and saves everybody time.

Please do not send in audio CDs or mp3 files to master from unless the audio CD or mp3 files are the only known source of the files. mp3 files are very poor quality and not suggested for use as a mastering source. This is especially true because your project will likely end up being converted to mp3 (again) for the end user resulting in “transcoding”. m3ps don’t always sound bad, but an mp3 of an mp3 will definitely sound terrible.

Audio CDs are not ideal to master from for many reasons. If uploading the files isn’t an option, you can send your mixes on a DATA CD (or DVD), hard disk, or flash drive. If your master files have ever been mp3s or on an audio CD, please get the 24-bit raw mixes as data files directly from your mix engineer.

Once audio files have been burned to an audio CD or converted to mp3, there is no way to get the quality back that is desired for mastering.

DATA CD/DVD or flash drives can be mailed to:

Mystery Room Mastering
2858 University Ave #212
Madison, WI 53705

After the Mastering Session

When the initial mastering is finished, an email with a download link will be sent to approve the master. Once everything is approved and finalized, a master will be supplied for the format(s) you requested. Most CD manufacturers will accept a DDP file as the audio master, which can easily be delivered via Internet. No physical CD-R required.

Check with your CD manufacturer because it’s an easier and better method to use a DDP file rather than a CD-R master. CDs are much more prone to errors, and will always contain some level of micro-errors. All audio master CD-Rs from Mystery Room Mastering are tested for C1/C2 errors to be sure the error rate is within spec to be used as a master CD, but by submitting a DDP file for a CD production master, there is no place for those errors to occur which is one reason why DDP is superior to CD-R for masters.

Add $50 for preparation, testing, materials, and shipping of physical master CD-Rs for production per disc and/or format to your manufacturer.

If you’re releasing your project via online distribution, be aware of what file type you need. Most online distribution services require 16-bit/44.1k WAV files as the master source. Bandcamp and SoundCloud can accept 24-bit WAV files with sample rates higher than 44.1k which will usually result in a better sounding experience for the end user.

The Apple Digital Masters program is also available from certain digital distributors and this means you can upload higher resolution files as the master source that will be converted to AAC format, which is what the end user purchases or streams. Apple Digital Masters is a special program and different than standard iTunes Store releases. Using Apple Digital Masters typically requires that a separate release be set up with your online distributor, which can also be an extra cost with them.

For more info on what formats of your master you may need, visit this page.

Vinyl Pre-masters

For vinyl pre-masters, one 24-bit WAV file for each side of the record will be prepared. Unlike audio CDs, vinyl has no limitations when it comes to bit-depth or sample rate, so rather than reduce the audio to CD quality and then transfer to vinyl, it’s best to keep the audio at 24-bit and the native rate if higher than 44.1k. Other sonic adjustments are made as well to optimize for the lacquer cutter/pressing plant. The reason for one file per side is to assure that the spacing between songs, and song order can’t be altered accidentally. A PDF file with song info and times will be provided so the cutter knows where each song starts and ends.

Submitting new mixes, or remixes after the initial mastering is done is subject to further billing, but the basic mastering rate includes unlimited revisions on the files you initially submit for mastering until you are satisfied with the results. Even the smallest mix change can require a lot of work to reprocess and remaster the new mix through the analog equipment and other various steps. This is why it’s important to be sure that there are no errors with the files you are submitting that can be easily corrected before the mastering begins.

Please send payments via check or money order to:

Mystery Room Mastering
2858 University Ave #212
Madison, WI 53705

Venmo, PayPal, and most major credit cards accepted as well.

If you have any questions, feel free to email me.

Justin Perkins
Twitter: @MysteryRoomMKE