Mastering Information

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, and upload the audio files. Or, 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 & WAV files)
  • album name or release/project name
  • 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 name or working title rather than the new name for reference.
  • format(s) in which the project is being released (CD, vinyl, online/digital distribution etc.)
  • ISRC codes are optional and can be provided for a small fee if you do not have your own. You will likely need them for online distribution. Some online distribution services provide them as well but having them generated from the start ensures the codes are applied to all master formats rendered by Mystery Room Mastering.
  • If you’d like the album cover art embedded into an mp3 version, please email a .jpg or .png file along with the audio files, or as soon as it’s available.
  • 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, so please be sure to send the track order in a separate list to be sure.
  • If you have a stylistic preference, make it known before mastering begins. Some want a master that is as loud as the average commercial CD these days, while some prefer to preserve more of the dynamics, and sacrifice some overall loudness. Please let it be known if you have a preference either way.
  • As for any noises, count-ins, or talking before & after any songs, make note if those sounds should stay in or be cut out. 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 from song-to-song if precise transitions are desired between certain songs. The file can be an mp3 for ease of sending as I will just be using it as a template when sequencing your master.
  • If you’d like me to reduce any equipment noise or tape hiss during intros, outros, or other quiet parts where any hiss is especially noticeable, please be sure to include a sample (at least 1 second) of ONLY the hiss (with no music or other sounds) before or after the song. Generally speaking, any hiss within a song typically appears louder after it’s mastered unless some noise reduction is done, so if you think any hiss or noise may be a problem, be sure to include a hiss sample for each song in question so an attempt can be made to reduce the noise.

Preferred Audio File Types

    • Your final mix files can be stereo (interleaved) .wav or .aif files
    • 24-bit audio files are strongly preferred, 16-bit files are ok when 24-bit (or 32-bit float) files are absolutely unavailable.
    • Preferred sample rate is whatever the original recording and/or mix session was. Basically, there is no need to up-sample files to a higher sample rate once they’re printed. Don’t convert mp3s to WAV for mastering.
    • Please be sure that the mix files have reasonable volume headroom to work with. It’s hard and sometimes impossible to do anything useful (sonically) to mixes that already have a high RMS (average volume) level.
    • 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 adding an L2 Limiter (or something similar) is simply for the sake of loudness, it’s preferred that processing is removed before making the final mix files for mastering. The master can be as loud as you’d prefer, but it’s hard to do a quality mastering job when the mix files are already super loud or have limiting applied.
    • 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. If the mix level is not going over 0dBFS, and there is no limiting on the master fader, the levels should be acceptable for mastering. It’s becoming more common for mix engineers to show clients mixes with some “faux-mastering” added for loudness, but ideally the mix engineer will remove that “faux-mastering” and create a 24-bit mix file without any limiting and loudness processing for the actual mastering session. 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, and can only be undone from the mixing source.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 work, 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 folder. 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.

If you prefer to share a link or folder, Dropbox is the 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.

Share your folder with the following Dropbox account ID:

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 and saves everybody time.

Please do not send in audio CDs or mp3s to master from unless the audio CD or mp3 files are the only known source of the files.

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 raw data files directly from your mix engineer. Once the files have been burned to an audio CD or converted to mp3, there is no way to get the resolution or 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) needed. Most CD manufacturers will accept a DDP file (which can be delivered via Internet). Check with them as it’s an easier and better method to use a DDP file rather than a CDR master which is much more prone to errors, and will always contain some micro-errors. All audio master CD-Rs 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 $20 for preparation, testing, materials, and shipping of physical master CDs for production per disc and/or format.

If you’re releasing your project via iTunes or another form of Internet distribution, let it be known what file type you need. Most online distro services require 16-bit WAV files to start with, and they handle the conversion to mp3 or various formats downloaded by the user. Others require files that are already in mp3 format and they simply host the mp3 files provided. There are a few bit rates to choose from within the mp3 format, so let it be known if a certain bit rate is desired. 320kbps mp3s will be provided unless directed otherwise.

Vinyl Masters

For vinyl 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 rate or sample rate, so rather than reduce the master 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, as well as leave some more dynamics and headroom/breathing room in the music for the lacquer/vinyl cutter to work with. The reason for one file per side, is to assure that the spacing between the songs, and song order won’t get changed accidentally. A PDF file with song info & times will be provided so the cutter knows where each song starts and ends.

***If using United Record Pressing (or other pressing plant that requires a CD-R master rather than 24-bit data file that can be sent via Internet), add $20 for burning, testing, materials and shipping a physical master CD-R.

Submitting new mixes, or remixes is subject to further billing.

Please send all payments via check or money order to:
Mystery Room Mastering
2858 University Ave #212
Madison, WI 53705

PayPal and most major credit cards accepted as well.

*PayPal or Credit/Debit card payments may be subject to a 3% transaction fee. This allows mastering rates for everybody to be as low as possible.

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

Thank you.
Justin Perkins
Twitter: @MysteryRoomMKE