Bristol-based mastering engineer Izzy McPhee has built her career around understanding how a track should sound and, just as importantly, how it should feel. Growing up surrounded by a wide mix of musical genres, she developed a strong ear for music that was later shaped by more than ten years of DJing and critical listening.
Over the past four years, Izzy has accrued more than 700 mastering credits, working across a broad range of genres with artists including Walt Disco, Dream Wife and Newton Faulkner. Her work has also earned recognition from the Music Producers Guild and Arts Council England, which identified her as an emerging talent in mastering.
Alongside her studio work, Izzy is a passionate advocate for greater diversity, equality and inclusion across the music industry.
For anyone who might not fully understand what a mastering engineer does, how would you describe your role and where mastering fits into the process of releasing music?
Mastering is the final step in music production — polishing a song sonically so it sounds great on any speaker, and technically so it's ready for release, whether that's streaming, CD, or vinyl. I break the process into three steps.
Step One: Quality Check — I critically listen to the track in my studio, checking for issues like unwanted distortion, dropouts, or other anomalies, while getting a feel for what the track needs to really shine.
Step Two: Audio Processing — I handle essential repairs like de-clicking or cleaning up noise in the intro/outro, then apply EQ, stereo enhancement, and limiting to give the mix a finished sound and a volume level that holds up against other tracks in its genre.
Step Three: Creating Formats — Once you're happy with the masters, I prepare the final files for distribution, complete with the right metadata — whether that's digital WAV files for streaming platforms, vinyl sides for pressing, or a DDP file for CD manufacturing.
Mastering brings a fresh, objective perspective to music you may have spent weeks, months, or even years creating. I have actively listened to thousands of songs, I've developed an ear for exactly what a track needs to get it over the finish line. That comes with a deep understanding of different genres and how listeners actually experience them, so your song sounds great whether it's coming through AirPods, a car stereo, or a big PA system at a live show. Just as important is understanding your vision as an artist — whether you want the track delicate or in-your-face, crystal clean or grungy — and making sure that comes through in how I approach the master.
You’ve now worked on hundreds of tracks across different genres. What do you listen for first when a track comes to you for mastering?
First of all, I’m checking if the track is in a position where I can technically proceed with mastering. Are any of the instrument stems missing? Is the audio cut off 3 seconds early? Is the track high resolution? It’s my job to flag and rectify it before I continue.
Then, I’m listening for anything that helps me understand the context of the track and how it will be consumed by the average listener. For example, what genre does this track sit in? Will it most likely be listened to on a phone speaker, or a club sound system? I need to take all of this into account when mastering so I can ensure the track translates well across the board. I will often use reference tracks provided by the artist, or ones that sit in similar genres to help me map out the approach I want to take in mastering.
Then I focus on things that help me understand the artist’s vision. This can include the feeling it evokes, the pace, the key, the instrumentation, the lyrics. What does the artist, producer and mix engineer want to really sparkle in this track? What can I do to make that happen?
What’s your favourite part of being a mastering engineer, and what’s your least favourite part?
I love that each day can look completely different! As I could be working on electronic club music in the morning, country in the afternoon and film score in the evening. Traditionally, mastering engineers don’t specialise in one genre, we get to work on lots of different ones. This suits me as I enjoy a really wide breadth of music, and that’s what I get to enjoy in my working day.
My least favourite part is staying on top of archiving and backing up files. The nature of working on potentially 8 different tracks a day with 8 different clients, means 8 different projects and lots of files that need to be correctly stored, in multiple places. After a certain amount of time, they get moved to an offline hard-drive. It’s not the glamorous part of the job, but super important! It’s a part I’m happy to do as I am very grateful to work on amazing music everyday.
Networking can feel quite intimidating when you’re new to the music industry. What’s one networking tip that has genuinely helped you?
As an introverted person, this part of the job was very scary at first. I’ve been lucky enough to have a fantastic manager, Brendon Harding, who has shown me that networking can actually be a way to forge wonderful, long-lasting professional relationships in an authentic way that doesn't always have to feel transactional. By showing up and supporting your friends and colleagues in their ventures, being in the room and being authentic in what you put out, it allows you to build relationships with good people that you align with.
One tip that has really helped me, is to have a ‘networking buddy’. Someone who is in a similar field to you, at a similar point in their career and who could also benefit from meeting new people too. Aim to attend events together, and then you can bounce and riff off each other. In my experience, it makes networking way less scary!
For someone interested in mastering but with little or no professional experience, what would you suggest they start doing now to develop their ears and skills?
Critical listening! This is still something I practice even after working in mastering for 4 years. But at the start when I was still finding my feet, I spent hours listening to music, especially on the speakers and headphones I was mastering on at the time. I didn’t start with top of the range audio equipment, but I knew it really well and knew exactly how music should sound on my setup. I challenged myself to listen to as much current and popular music as I could, but also genres that I wouldn’t normally reach for.
I would then turn on my ‘critical ear’, so listening for production choices, mood, pace, key, dynamics. How did all of these elements make the song what it is? As I have been a DJ for over 10 years, dissecting music in this way already came naturally to me, so I just continued to develop this skill.
You’ve already built up more than 500 mastering credits. What do you think helped you turn those early opportunities into consistent work?
Always being open to improving and continuously learning how to be a better mastering engineer, which has meant I have been able to grow with clients that were with me from the start.
But also, a big part of the service I offer is being a good communicator. I have a lot of important info clearly laid out in PDFs so people know exactly what I offer and what I need from them for us to work together. I also strive to make sure the artist, producer or mix engineer always have a direct line of contact to me if they want it, and that they feel they can ask questions and give feedback. One round of revisions is included in the initial cost, and I am always happy to do this in order to get it right.
Basically, being part of the team! Being on their side, working to get the music to it’s full potential, whilst being empathetic to every process, hour and decision that has already happened before the track makes it to me.
What’s one mistake you see artists or producers make when preparing a track for mastering, and what should they do instead?
It’s always worth checking in with your mastering engineer how they want a pre-master to be delivered. We are often fast-approaching a deadline when we get to the mastering stage, so ensuring your pre-master is to the specification your mastering engineer needs, can avoid wasted time rectifying the issue.
Often people put a few plug-ins on their master bus, such as a compressor. I always ask people to export their pre-master with anything contributing to the ‘vibe’ of the track ON, and anything contributing to loudness (so basically just a final limiter) OFF. The reason for this is, compression, saturation or even clipping on the master-bus has contributed to the sonic character of the track, and this is what the artist, producer etc. has therefore approved. By leaving the limiter off, it allows me headroom and the ability to get the track to a competitive volume that I deem right as the mastering engineer.
It can be helpful to deliver a ‘loud reference’ or ‘listening copy’ along with your pre-master. This is a version with the limiter on too, so I know what sort of level you’re aiming for.
What’s your best piece of advice for a young person trying to build a career in music or audio right now.
Spend time absorbing as much music as you can, and be open-minded to genres and styles you might not naturally reach for. You don’t have to have thousands of pounds worth of equipment to get started, training your ear is something you can start doing now for pretty much free! There is a great website called Tone Gym, which offers free ear training games too. All of this is honing your critical listening skills and your breadth of musical knowledge.
Also, always prioritise being a good person and showing up in a way that feels authentic to you, forge meaningful connections and get involved in musical communities that make space for you. When I connect with people in these spaces, I often feel way more comfortable to ask questions and speak up.
For example, I’m very passionate about gender equality in music so I always seek out spaces, platforms and organisations that centre this - like shesaid.so!