Mastering with Mat Leffler-Schulman: why attention, relationships, and perspective matter

Today, we’re interviewing Mat Leffler-Schulman, a GRAMMY-nominated mastering engineer based out of Baltimore, Maryland. Operating out of a purpose-built studio, Mat brings a blend of analog intuition, digital precision, and grounded perspective to the records he touches. Mat’s process offers a valuable glimpse into what it means to master not just music, but a sustainable career in audio, so read on for some inspiring words.

Getting started with mastering

Mat Leffler-Schulman didn’t intend to become a mastering engineer. For 15 years, he was a studio owner and producer in Baltimore, deeply embedded in the personal world of recording.

"When you're with a band for two weeks, it's so intimate – sort of mentally draining. I sort of burned out on that. I think that’s something people don't talk about a lot."

At the same time, he found people came to him with mastering jobs. “I was mastering records here and there, all in the box,” he told me. “It was just an added bonus, for either the records I was working on, or people who just found me."

At a certain point, Mat made a change: he and his wife decided to close the studio, move to Europe for the year, and reset. When they came back, they painstakingly built a mastering studio into their home, and Mat set himself on a path of working on records for acts like Beach House, Ice Cube, Jon Batiste, Blondie, Will.i.am, and others. 

Now he feels like he has the relationship he wants with clients. “I'm not working with a band for two weeks,” he told me, “I'm working with a producer or a mixing engineer for a day.”

Mat's mastering workflow

Like many engineers, Mat is happy to dive into his workflow and perspective on the process of mastering. I’ve broken his process down into several digestible sections, starting from the beginning.

Upon getting the project

Mat begins each session with a precision listening phase, using iZotope  RX  as his first line of defense.

“I'm always listening to everything in RX before I get started with anything,” He told me. That way, he can get a lay of the land for any potential errors that might’ve crept into the mix.

Because of the heavy workload many working engineers face, it’s not uncommon for clicks and pops to go uncaught. These are issues mixing engineers might not have had time to correct – problems frequently introduced by the actual render.

“There's often errors that happen in that rendering process with plugins, or crossfades, and it ends up giving you pops and clicks,” Mat said. “You wouldn't necessarily hear that in your DAW, but after it's been rendered, they're there.”

So he gets to work RX’ing the little details that slip by us mixing engineers.

“Nine times out of ten, I’m fixing pops and clicks – probably a dozen of them per mix.” 

Mat was careful to stress that this is a workload problem, not a skill issue: time constraints are a fact of life for everyone from newbies to GRAMMY-winning mixers. Indeed, this is a top reason to seek out a dedicated mastering engineer in the first place, as AI isn’t going to fix clicks and pops for you.

Once these issues have been handled, Mat works a little differently depending on the situation. If he’s working on a record mixed by one person, he treats it a little differently from a project with multiple engineers.

Let’s take the first fork of the road now.

On a record mixed by one person

When a single engineer has mixed the entire album, Mat thinks holistically about the project, working primarily with his hardware and his Maselec console.

“For the most part, my analog gear is doing the same thing for almost every song,” he said. “Maybe there's an EQ change for each song, but the compressor is generally doing the same thing, and the console's probably doing the same thing – how I'm hitting my transformer box, it’s generally the same thing for each song.”

This allows him to use his hardware to make broad changes that benefit the album as a whole.

Sometimes his workflow is linear, going from song to song. Sometimes it’s more of a needle drop affair, and he’ll be “going back and forth between songs and figuring out where all the gear sounds the best.”

Throughout this process, he’s tweaking things, to either fix problems or just sweeten.

Think of it this way: if a mix engineer is working out of a room with its own set of issues, then regardless of the song, the whole album will be influenced by those problems. With his hardware, his carefully-tuned room, and his ears, he can account for such global phenomena here, in the hardware phase, all while securing the right flavor for the project.

“Nine times out of ten,” he said, “I get the vibe from my analog gear.”  There is the occasional outlier, however.

“Every once in a while, I'll print a song, and it'll be two parts,” he told me. “I’ll need to change the EQ somewhere, almost like an automation.” When this happens, he simply prints the two different passes he needs and stitches them together.

But again, this is the outlier.

Most importantly, he’s making changes to benefit the album as a whole, rather than a song.

“It's setting the vibe for the record,” he told me, “gelling the whole record together. And then after I've done that, and it's sitting right as a whole – then I can go in and I can pull up my go-to digital tools.”

More on his favorite plugins – including iZotope specialities – later. First, let’s tackle the other common scenario.

How to handle a record with multiple mixers

What about a record with more than one mixing engineer?

Here, Mat notes that a different approach is required. “You almost treat it like a compilation,” he said, “where every song is just so isolated.” 

This kind of project requires spending more time getting each song’s individual issues ironed out. Then comes the vibe, and finally, he’s “making sure the levels are good at the end.”

Plugins and digital – where does it all fit in?

Regardless of whether he’s working on a cohesive record or something with multiple engineers/artists, sometimes digital tools are needed to take everything where it needs to go.

Digital processes can occur before the analog pass (the “pitch”, it’s often called) or after (the “catch”). Still, it’s roughly true that analog sets the vibe, while digital handles the details.

Among Mat’s favorite digital tools are the  Ozone  EQ module (“it sounds awesome”) and the Dynamics module.

“I love the dynamics module in Ozone,” he told me. “I use the multiband all the time. That's like such an insanely precise tool.”

Just because it’s multiband doesn’t mean he’s using all four bands all the time. “For the most part,” he said, “I’m only using one or two bands, usually like way up high and usually down low.” The rest of the bands he leaves alone.

Mat is also using a tool that he and I have had access to for a while: Ozone 12.

The newest iteration of Ozone has some really revolutionary features, including a full-out Stem EQ (for tweaking bass, vocals, and drums independently within one instance), a Bass Control module (for helping low-end material sit right), and a new Unlimiter module that restores dynamics to overly-squashed material.

The Unlimiter is particularly helpful in Mat’s workflow. “I get a lot of 90s records that were mastered for CD, and they’re just so crunchy. I've used the Unlimiter, and you can get an extra two or three dB back into it. It just blows my mind away.”

In fact, he had recently used the Unlimiter when we spoke, as he had been supplied “a 16-bit CD that clearly had an L2 on it completely slammed.” With the Unlimiter in tow, he could “pull usable transients out of a waveform with almost zero crest factor left.”

He stressed, “it’s not just a transient shaper, it uses some freaky-smart multiband envelope recovery to reintroduce punch specifically in the drums! And I, being an ex-drummer, am particularly focused on the transients of drums. Easily the most useful transient tool I’ve used on post-limited program audio.”

Analog gear

Among the usual tools that many mastering engineers have, Mat has some special, one-of-a-kind pieces. Take his stereo Pultec-style equalizer made by Manley Labs.

“The cool thing about my Manley Pultec,” he told me, “is it's the only stereo mastering one in existence.”

Indeed, when he posted pictures of it to Instagram, Eveanna Manley reached right out. 

“She was like, ‘this is the only one we've ever made. Can you send it to me so I can take pictures of it?’ So I sent it to her and she rehabbed it for me.”

He also has a rare precursor to the famed Sontec EQ – the ITI/Sontec MEP-130 Dual Parametric Mastering Equalizer.

“Oh my God,” he told me, “it's my pride and joy. It’s such a cool piece, and it sounds fantastic.”

Advice for the up-and-comer

With his workflow discussed, we moved on to the topic of advice. Here we can roughly split the conversation into two topics: craft and business.

Craft

First and foremost, Mat recommends getting acquainted with the tools you already have. 

“It's harder to learn all the gear when you have it all, as opposed to having a couple pieces here and there.” Having only a few pieces allows you to “really kind of have to dig in.” 

He also warns about overprocessing. 

“If I have any more than three [hardware] inserts on, that generally is a sign that I need to start over again and just simplify.” 

It’s a rule he’s made for himself: “Once I hit that fourth insert, I know that I'm not looking at it from the right perspective. I need to stop what I'm doing, reset, and start again. And I feel like nine times out of ten, when I do it that way, I have a fresh perspective, and I get it nailed in five or ten minutes.”

Business

Mat’s position on the business is one of slow growth and reasonable outcomes. “You've got to be in it,” he told me. “It's the long game – the setup's going to take a long time. But once you've got a couple seeds in, they start popping up.”

He’s referring to the age-old practice of making friends in the business and not expecting things from them right away.

“You have to network,” he told me. “I don't know if it's my Jewish genes, but like, we network! We talk to people! We introduce people to other people 'cause you never know down the road, that person's gonna introduce you to someone else. That's gonna help you.”

As a fellow member of the tribe I can attest to this strategy: everything I’ve got came from schmoozing – itself a Yiddish word. 

But how do you network in these digital days? 

Either you get out in your scene, or you spend time doing the digital equivalent: ”going on Instagram and finding people you want to work with.”

You don’t simply insert yourself. Rather, you spend time “befriending them. Talk to these producers and say, ‘Oh, my God, like, I love that record. How did you get those drums to sound that way?’ Then, you build up a rapport, and then eventually they're gonna be like, ‘Oh, wait, you're a mixed engineer. I'm gonna send this mix to you and see what happens.’”

He recommends that you keep everything gradual and focus on slow growth. “I don't want to be having 20% or 30% growth every year,” he told me, “because then the next year after that, you're going to have 2% or low growth or no growth. And that's daunting to me. So I've always had slow growth. It's attainable to sustain that.”

Get inspired to master your music

Mat Leffler-Schulman’s story is a reminder that mastering isn’t just about gear or technique – it’s about attention, relationships, and perspective. From his use of iZotope’s most powerful tools to his rare, one-of-a-kind analog pieces, Mat’s approach is as much about vibe as it is about detail. 

Whether you're new to mastering or fifteen years deep in the game, there’s something to learn from how he listens, how he works, and how he connects with people. 

Discover Ozone