What Happens After Mastering

You approved the master. So what comes next?

The answer depends on where your music is going. Digital streaming, vinyl, CD, and cassette each have different requirements and different pipelines. Understanding what happens after mastering helps you plan your release properly and avoid the kind of last-minute scrambling that costs time and money.

Here is what the process actually looks like.

You Receive Your Files

After approval, I deliver a complete set of files specific to your release format. For digital releases this typically includes 24-bit WAV masters at the resolution of your source files, and a 16-bit/44.1kHz Red Book version for CD and general distribution.

The difference matters. 24-bit audio has a theoretical noise floor around 144dB, compared to 96dB for 16-bit. That headroom is real and audible in quiet passages and subtle details. When converting from 24-bit to 16-bit, dither is applied, a small amount of shaped noise added to the signal that preserves low-level detail and prevents quantization distortion at the bit depth boundary. This is done once, at mastering, and it is one of the reasons you do not re-process your files after delivery.

Every file comes with embedded metadata: artist name, track titles, ISRC codes if you have them, and any other information relevant to your release. For WAV files this is stored as BWF (Broadcast Wave Format) chunks. If something is missing or needs updating before delivery, that is the time to sort it out.

For projects releasing on Apple Music, I also offer Apple Digital Masters delivery, which meets Apple's specifications for high-resolution audio on their platform.

Digital Distribution

For streaming and download releases, your mastered WAV files go directly to your distributor, DistroKid, TuneCore, CD Baby, or whichever platform you use. Upload the highest resolution files your distributor accepts. Do not re-encode, re-process, or enable any loudness or enhancement options your distributor offers before uploading. The master is done. Leave it alone.

Your distributor handles the conversion to the formats each platform requires. Spotify encodes to OGG Vorbis at 320kbps for premium subscribers. Apple Music uses AAC at 256kbps, and also offers lossless ALAC streaming if your files meet their specs. Tidal streams FLAC at CD resolution or above for their HiFi tier. Each of these is a lossy or lossless transcode from your WAV master. What matters is that what you hand them is the cleanest, highest resolution version of the master, the transcode quality is only as good as what it starts from.

One thing worth knowing: loudness normalization means your master will be turned down on most platforms if it is louder than their target. Spotify normalizes to -14 LUFS integrated. Apple Music targets -16 LUFS. Tidal and YouTube use -14 LUFS as well. This is expected and accounted for in the mastering process. A master prepared correctly for streaming will sound right after normalization, not just before it.

CD Manufacturing

If you are pressing CDs, your master goes to the manufacturer as a DDP file set (Disc Description Protocol) or as individual WAV files with a cue sheet, depending on what your plant accepts. DDP is the professional standard and what most plants prefer.

A DDP contains everything needed to replicate the disc exactly: the audio stream, the PQ subcode data that defines track starts and indexes, ISRC codes embedded per track, UPC/EAN for the disc, and CD-Text if included. It also generates an MD5 checksum, a unique hash value calculated from the sum of every byte in the file. The plant uses this checksum to verify that what they received matches what was sent, byte for byte. Any corruption or transmission error produces a different hash and gets flagged before pressing begins.

Do not burn a CD-R and send it as your master. Plants can work from them, but jitter, read errors, and Orange Book vs Red Book compatibility issues make them less reliable than a proper DDP. Red Book is the CD audio standard, 16-bit, 44.1kHz, two channel, maximum of approximately 74 minutes, and your master is built to those specifications.

Your plant will press from this master and send you a proof or test disc before the full run. Listen to it. The whole thing. Not just the first track.

Vinyl

Vinyl is its own process and deserves its own attention.

Your vinyl pre-master is a separate deliverable from your digital master. The differences are significant. The RIAA equalization curve applied during cutting boosts low frequencies and cuts high frequencies going onto the disc, then reverses on playback. This means excessive low end, particularly below 300Hz, gets amplified at the lathe and can cause the cutting stylus to over-travel its groove width, resulting in distortion or a skip. Low end in vinyl masters is sometimes (but certainly not always) summed to mono below a certain frequency for this reason, and bass-heavy or phase-heavy content requires careful management.

Stereo width is also constrained. Out-of-phase low end is one of the most common causes of cutting problems. A vinyl pre-master is checked for phase coherence, and the stereo image is managed to keep the cutting stylus within safe parameters without flattening the width of the record unnecessarily.

Level is lower than a streaming master. The louder a vinyl master is cut, the wider the groove, which means fewer grooves per inch, which means less playing time per side. A louder cut is also harder to track. Side length, level, and dynamics are all in conversation with each other.

That pre-master goes to a cutting engineer, who cuts the lacquer, an aluminum disc coated with nitrocellulose lacquer, that becomes the source for your pressing. The lacquer is then electroplated to create metal stampers, which press the final records. Depending on the plant and your budget, you may receive a test acetate or test pressings before the full run is approved. If test pressings are available, request them. Listen on a known system. Listen for distortion in the inner grooves, for low end that pumps or skips, for sibilance that bites harder than it should. Inner groove distortion is a physical reality of the format, the geometry of the stylus tracking a tighter spiral near the label means high frequencies are harder to reproduce cleanly, and a well-prepared master accounts for this in the sequencing and level decisions.

If something is wrong at the test pressing stage, it can be corrected. After approval, it cannot.

For a deeper look at how the vinyl process works, see What Is Vinyl Pressing?

Cassette

Cassette duplication is simpler than vinyl but has its own considerations. Your master goes to a duplication house, who transfers it to tape at their facility. Most cassette duplicators work from WAV files.

Tape has a frequency response that rolls off in the high end, and that rolloff varies depending on tape formulation. Type I (ferric) tape has a softer, warmer top end. Type II (chrome) extends higher and handles transients better. Bias, the high-frequency AC signal used to linearize the magnetic recording process, affects how each formulation behaves, and duplicators set bias for their tape stock. A cassette master that sounds right on a well-biased machine may sound dull or harsh on a cheap one, and there is no way to fully account for every playback device. The goal is a transfer that sounds right on a known, well-maintained reference deck.

Noise floor is a genuine consideration. Cassette tape has an inherent noise floor that digital does not, a standard Type I ferric tape sits around -50 to -55dBFS, compared to the theoretical -96dBFS of 16-bit digital. That gap is audible in quiet passages and sparse arrangements. Dynamic range on cassette is typically 50 to 60dB, compared to around 96dB for CD. The distance between your quietest and loudest moments has to fit within a narrower window than any other format you are likely to release on.

A cassette master that is too dynamic will drop quiet passages into the noise floor. One that is too compressed will sound airless. Getting the level and dynamic balance right for the format is part of what the master needs to do.

As with vinyl, request a reference before approving the full run if your duplicator offers one.

Metadata and Registration

Before your release goes live, make sure your ISRC codes are registered and your PRO registrations are in order. An ISRC, International Standard Recording Code, is a 12-character alphanumeric identifier assigned to a specific recording. The format is country code, registrant code, year, and designation code. ISRCs are embedded in your mastered files and in the DDP if you are pressing CDs. They are what SoundExchange uses to track and pay out digital performance royalties, and what streaming platforms use to identify recordings uniquely across their systems. If you do not have ISRCs, get them before your release goes to distribution.

Mastered files with embedded ISRCs help, but registration with SoundExchange, ASCAP, BMI, SESAC, or your relevant PRO is a separate step that too many artists skip until after the fact. Embedded metadata travels with the file. Registration is what actually triggers royalty collection.

This is also the time to confirm your UPC, your release date, and your artwork specs with your distributor or manufacturer. Getting this right before delivery saves the kind of delays that push release dates.

What Mastering Does Not Cover

Mastering gets your audio ready for release. It does not register your music, distribute it, design your artwork, or manage your rollout. Those are your responsibilities or your label's.

What it does is hand you something release-ready. The rest of the process is yours to run.

Ready to get started? Submit your project here.