Mixing vs Mastering: What Is the Difference?

# Mixing vs Mastering: What Each Stage Does and Why They Are Separate

Mixing and mastering are two distinct stages of post-production, and confusing them is one of the most common mistakes artists make when planning a release. They are not interchangeable, they are not the same job done twice, and collapsing them into a single step almost always produces a worse result. Understanding what each stage actually does will help you make better decisions about your music, your budget, and who you hire.

The short version: mixing is about the relationship between elements inside a song. Mastering is about preparing that finished mix for distribution. Both require different tools, different monitoring environments, and a different set of ears. At Animus Studios we handle both in-house, but we keep them deliberately separate, often with a gap of at least a day between finishing a mix and beginning the master.

This article breaks down what happens at each stage, why the separation matters, and what you should expect to receive from each process.

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What Is Mixing?

Mixing is the process of taking every recorded element in a session, whether that is 48 tracks of a full band, a rapper's vocal chain, or a voice artist's single mono recording, and balancing them into a cohesive stereo (or sometimes immersive) output. The mix engineer works inside the multitrack session, which means they have access to every individual sound: kick drum, snare, bass, guitars, synths, lead vocal, backing vocals, effects returns, the lot.

The core decisions in mixing are level, panning, EQ, dynamics, time-based effects, and automation. Every one of those decisions affects how the listener perceives the song. A kick drum that sits 2 dB too loud in the low-mids will make a mix feel heavy and congested. A vocal that is not riding the arrangement will disappear in the chorus. These are problems that only exist inside the multitrack, and they can only be fixed at the mixing stage.

The Tools of Mixing

At Animus Studios, our mix sessions run in Pro Tools at 48kHz, 24-bit as standard. We work across a combination of hardware and software processing. On the software side, we use FabFilter Pro-Q 3 for surgical EQ work, Waves SSL G-Bus Compressor and API 2500 for bus compression, Soundtoys Decapitator and Radiator for saturation, and iZotope RX for any noise repair that needs to happen before the mix stage. For reverb and spatial work, we draw on Valhalla, Lexicon, and UAD plate emulations running through Universal Audio Apollo interfaces.

The mix engineer is making hundreds of micro-decisions across a session. A typical mix at our studio involves:

• Gain staging: Setting every track so that signals hit processing at the right level, generally keeping individual tracks peaking around -18 dBFS to give headroom for dynamics processing
• EQ and filtering: Carving space for each element so they are not competing in the same frequency range
• Compression: Controlling dynamics on individual tracks, buses, and the stereo mix bus to add cohesion and punch
• Effects: Reverb, delay, chorus, saturation, and other processing that shapes the character and space of the record
• Automation: Moving faders, effects sends, and parameters over time so the mix breathes and responds to the arrangement

The deliverable from mixing is a stereo mix file, typically exported at 48kHz, 24-bit WAV, with a few dB of headroom left at the top. That file goes to mastering.

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What Is Mastering?

Mastering is the final stage of audio production before distribution. The mastering engineer works from the finished stereo mix, not the multitrack. They do not have access to individual tracks. Their job is to optimise that stereo file for playback across every format and platform: streaming services, CD, vinyl, broadcast, sync licensing, and so on.

The mastering stage addresses overall tonal balance, stereo width, dynamic range, loudness, and sequencing if you are releasing an album or EP. A good mastering engineer will also catch problems in the mix that were not audible in the mixing environment, which is one of the reasons a second set of ears at this stage is genuinely useful, not just a formality.

Loudness and Delivery Standards

One of the most concrete functions of mastering is hitting the right loudness target for your release format. Streaming platforms like Spotify, Apple Music, and YouTube all use loudness normalisation, which means they will turn your track down if it is too loud. The standard target for streaming is around -14 LUFS integrated, measured across the full track. Pushing a master louder than that does not make it sound louder on streaming, it just gets turned down to match everything else, and often sounds worse in the process because of the dynamic range that was sacrificed to get there.

For CD, the target is different. For vinyl, different again. Mastering accounts for all of this.

The Tools of Mastering

Mastering requires a different monitoring environment to mixing. At Animus Studios, our mastering room is treated to a higher acoustic standard than our tracking and mixing spaces, and we monitor on Genelec 8351B speakers, which give us a flat, accurate picture of what is happening in the low end and the stereo field. We also cross-reference on multiple playback systems.

On the processing side, mastering typically involves:

• Linear phase EQ: Making broad tonal corrections to the stereo mix without introducing phase smear, using tools like FabFilter Pro-Q 3 in linear phase mode or the Dangerous Music Liaison for mid-side processing
• Multiband or dynamic EQ: Addressing specific frequency problems that only appear at certain moments in the track
• Stereo bus compression: Gentle glue compression to add cohesion and control the overall dynamic envelope, often using an SSL G-Bus or a Neve 33609 emulation
• Limiting: The final stage, where a transparent limiter like the FabFilter Pro-L 2 or iZotope Ozone Maximiser brings the master to the correct loudness ceiling, typically -1 dBTP (true peak) for streaming
• Mid-side processing: Adjusting the centre and sides of the stereo image independently to correct width issues or tighten up the low end

The deliverable from mastering is a finished, distribution-ready audio file. For streaming, that is usually a 44.1kHz, 16-bit WAV (Red Book standard) or a 24-bit high-resolution file depending on the platform. For sync and broadcast, we often deliver at 48kHz, 24-bit.

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Why Mixing and Mastering Must Be Separate

The most important reason to keep these stages separate is headroom, both technical and perceptual. A mix that has been pushed to mastering loudness levels before it reaches the mastering engineer has no room left to work with. The limiter has already been hit, the transients have been flattened, and the mastering engineer is working with a compromised file. We see this regularly when artists send us mixes that have been processed with a limiter on the master bus. The first thing we ask them to do is send the mix again without it.

The perceptual reason is just as important. The mix engineer spends hours inside the session. By the time they finish, their ears are adapted to that particular sound. A mastering engineer coming to the file fresh will hear things the mix engineer has stopped noticing: a slightly harsh upper-mid presence, a low-end build-up in the 80 to 100 Hz range, a vocal that is sitting just a touch too far back in the mix. That fresh perspective is part of what you are paying for.

There is also a technical argument for different rooms. Mixing environments are optimised for working across many tracks and making detailed decisions about individual elements. Mastering rooms are optimised for evaluating a stereo mix as a whole, with flatter monitoring and a higher degree of acoustic treatment. The same engineer working in the same room for both stages will always be at a disadvantage compared to two separate stages in two separate environments.

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What You Actually Receive From Each Stage

It helps to be clear about deliverables before you book either service.

From mixing, you receive:

• A stereo mix file (typically 48kHz, 24-bit WAV) with headroom for mastering
• Optionally, stems (grouped exports of drums, bass, instruments, vocals) for remixing or sync purposes
• A mix that is balanced, processed, and ready for mastering

From mastering, you receive:

• A distribution-ready stereo master at the correct loudness and format for your release
• A DDP image or individual track files if you are pressing a CD
• A high-resolution version if required for certain platforms or licensing
• Confidence that your release will translate correctly across playback systems

If you are releasing to streaming platforms, you need both. A mix without a master is not finished. A master without a proper mix is working with one hand tied behind its back.

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When You Need Both, and When You Might Only Need One

If you are releasing original music, you need both mixing and mastering. Full stop. If you have already had your music professionally mixed and you just need it prepared for release, you only need mastering. If you are a podcaster or voice artist releasing spoken-word content, you may only need editing, noise reduction, and loudness normalisation, which sits closer to mastering in terms of process. Our [podcast production](https://animusstudios.au/services/podcast-production) and [audiobook production](https://animusstudios.au/services/audiobook-production) services handle exactly that.

For artists recording original music, our [mixing](https://animusstudios.au/services/mixing) and [mastering](https://animusstudios.au/services/mastering) services are available separately or as a combined package, with both stages handled in-house at Petrie Terrace.

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Mixing and mastering are not the same job, and treating them as one is a shortcut that costs you in the final result. Each stage has a specific function, specific tools, and a specific deliverable. Getting both right is what separates a finished, professional release from a demo that almost made it.