Everything you ever wanted to know about Mastering Delivery Resolutions!
When you receive your master, you'll notice that there are several files and folders. Well, each one has a purpose and we have carefully proofed and QC'd them to make sure your Master is correct and complete.
What do these mean?
Let's start with the files for RedBook Audio CDs. You'll see folders that say "44-16" and a file that is called "DDPMASTER.ZIP
Your 44-16 folder has the tracks exported from the album timeline in our workstation exactly as they would be played in the Master. You can use these for digital distribution with TuneCore, CD Baby or other distributors, But, you should only use these when you cannot upload a higher resolution.
Your DDPMASTER.ZIP is THE MASTER that you can REPLICATE CDs from. This (or a physical CD with this data on it) is what you will send to the replication company to make your CDs. This file WILL NOT play on a standard CD player or on your computer. DDP stands for Disc Description Protocol and that's exactly what it does -- it's an archived group of files that describe the disc timing and content and tell the replicator how to make the CD. Your CD manufacturer won't DUPLICATE from this file. That's something different and we'll explain it in the Duplication vs. Replication area.
The resolution of Redbook Audio is 16-bit, 44.1kHz. It's just a specification to say that when you put these files on a CD, they will correctly play in any standard CD player and adhere to the following three specs: Lead-In Area, Program Area, and Lead-Out Area. This standard also supports CD-Text, which is a way of including the following metadata fields: Album Artist, Album Title, Track Title, Track Artist (usually a featured artist), ISRC, and UPC. We will include text in these fields that you provide to us and confirm in writing. We will NOT guess at what to put here or fill in anything automatically. Another clarification: when you put your reference in a computer for the first time and it loads into iTunes, you will NOT see track titles show up. This information is populated through Gracenote's database, and you can find a How-To on uploading to Gracenote on our site.
Next on our tour of audio resolutions is the "44-24" folder. This folder contains the files you should generally use for Digital Distribution sites like SoundCloud. These are also the files you should send to people for listening to your music -- it sounds pretty good, and isn't an mp3, but the file isn't as big as the full resolution master, so it's easier to send.
What's the difference between 16-bit and 24-bit (or higher)? Well, the difference in file size is the first thing some people notice. A 24-bit file is about twice as large as a common sample rate 16-bit file of the same length. However, after listening, you'll notice that a 24-bit file sounds much better than a 16-bit version of the same content. The reason for this is simply that the computer has many more steps or options for quantization (how the computer interprets the information stored in each sample) in a 24-bit file (~16,777,000) versus a 16-bit file (~65,000). The sound quality suffers in a 16-bit file in the very quiet and very loud sounds, and the high and low frequencies, and also the important but often forgotten reverb cues, overtones and intricacies of the music. Go ahead, take a listen! Even though we strive to always use the highest quality converters and dither, you can still hear the difference. WE encourage you to always use the highest resolution you can to show off your music in the best way possible.
Remember, your lower resolution files cannot be brought back up to high resolution by upsampling or upconverting. Once the data is stripped from the file, it is gone and the only way to get back to the higher quality is to go back to the full resolution master. This applies to lossy data compression files like MP3 and AAC as well. Once the WAV has been converted to these lower resolutions, you cannot simply convert back to WAV.
More and more artists are releasing their new music with a video component. This is where the "48-24" folder comes in. Use the 48kHz files wherever there is a video sync happening -- like a music video, sync licensing, or YouTube.
Now, on to your full resolution files, the “96-24” or “88-24” folders. We master everything at 24-bit and at a 2x sample rate (96kHz or 88.2kHz) if it came in a 1x (44.1kHz or 48kHz). If the files are delivered at a 4x (192kHz or 176.4kHz), they are, of course, mastered at that higher sample rate.
Why do we care about high sample rates? The simplest answer has to do with the frequency range available in the sample rate. The highest frequency able to be represented is one half of the sample rate. This is called the Nyquist Frequency. So if the sample rate is 48kHz, then the highest frequency that can be represented is 24kHz. But, if we record at 96kHz, then we can represent a frequency range all the way up to 48kHz. This is a huge improvement in the sound, expressed in the "air" of the vocals, the sizzle in the cymbals, and the expanse of the reverb, to name name just a few items.
If anything is unclear in this article, please let us know. We want you to understand how to put your best foot forward when getting your mastered files out in the world!