Inside the studio with over 10 billion streams to its name

Kevin Grainger and Cass Irvine of Wired Masters are the favourite mixing and mastering engineers for some of the world’s biggest dance and pop artists. We visited their incredible studios to hear their story and learn about their craft.

Hearing possibly the best sound you’ve ever heard is a strange experience. It’s like music acquires an extra dimension, with every element in a track sitting in its own space with crystalline clarity. I would have said things like “powerful,” “punchy” and “detailed” in the past to describe sound. But in Cass Irvine’s studio at Wired Masters, listening on two enormous PMC speakers in an immaculate acoustic environment, I used these words and really meant it.  

This level of quality is matched throughout the rest of Wired Masters, which is housed on a quiet industrial estate in south London. Cass and Kevin Grainger, his business partner of 20 years, have essentially created the facilities of their dreams. There are three state-of-the-art studios built at irregular angles within a beguiling industrial space. Each studio uses something called a jack-up floating floor system and weighs around 15 tons. “We wanted it to look like there were three studios just dropped by aliens in a warehouse,” Kevin said.   

The space feels like a culmination of the work Cass and Kevin have put in over the past 20-plus years. They got their start working on DJ mixes and compilations at a mastering house, before leaving to start Wired in 2003, with clients like Defected and Ministry Of Sound helping to build their reputation. Kevin, who was nominated for a Grammy for his mixing on Fisher’s “Losing It,” has gone on to work with Avicii, Joel Corry, Swedish House Mafia, Jax Jones, Charli XCX and Becky Hill, among many others. Cass, meanwhile, counts Camelphat, Galantis,  Loud Luxury, DJ Regard, Eats Everything and Sonny Fodera among his extensive client list.  

Cass and Kevin feel they’ve been able to reach this elevated position within their field by moving with the times. They were early adopters of stem mastering, the practice where instead of working with a single stereo file, as in traditional mastering, the engineer has access to multiple parts of a song—drums, bass, vocals, leads etc. In fact, Kevin’s work became so hands-on that he now exclusively works as a mix engineer. They are also huge advocates of software, welcoming advancements from developers like Ableton, UAD, Fab Filter and iZotope while older engineers around them turned their noses up. 

More than two decades of experience have given Cass and Kevin the confidence to talk about their profession with total honesty. This made visiting the studios both informative and entertaining, as we spoke about advice for aspiring engineers, the incredible space they’ve built, the process of mixing a track, and the many highs and lows of their long careers.


Let’s start with your advice for people who are interested in what you do and fancy getting into it. 

Cass: The most important thing they don’t teach you at music college is how to get a job. 

Kevin: How to present yourself. The amount of letters and emails that we get that is literally—dear insert name here. And it’s in a different font. You couldn’t even be bothered to make it the same font, and you want me to get back to you. 

We’re busy. We’ve got a lot of people who want to do this. I’m sorry. It’s like, “Dear studio manager.” It takes 30 seconds to go online and find out the person’s name. Put some effort in. It’s really common sense. 

How should people approach you? 

Cass: I think you have to personalise your approach. So if you’re going to a certain studio that does a certain genre, then you write a personal email and say that you’re really interested in that music. “I appreciate that you’re very busy but it would mean a massive amount if I could come in for a half day. I really loved that album you mixed.” Massage their ego. 

Then when you get in the door, pay attention. You don’t look at your phone. Be polite. 

Kevin: We’ve had people who sat there on their phone all day. 

Cass: And then afterwards you write an email saying, “Thank you so much for your time. I really appreciate it. Could I come back?” 

Kevin: That’s how all the guys who work for us got started. 

Cass: You have to create a job for yourself rather than sitting there waiting for it to come to you.

Kevin: You’re never gonna see jobs advertised. That’s why you have to find your way into places and impress them. 

The music business is quite flaky but it is a business. We’ve got deadlines. You might be the greatest producer or mix engineer in the world. But if you can’t hit those deadlines you’re not going to get repeat work. You need to show that from day one. You might have been on a big night out but we need you here at 9 AM. 

What about formal education? Is that necessary to work for you? 

Kevin: No, not bothered at all. All of our young staff have made tracks. Just don’t knock on my door if you want to be Hans Zimmer. We do house music, electronic music. 

Cass: All the guys who worked for us, they knew some Logic or Ableton. They could use an audio workstation, that was the most important thing. They knew how to use plugins. 

Kevin: They know what an EQ is. We don’t want to have to start from absolute scratch and explain beats and bars. But other than that… We like teaching people our way of doing it.

Cass: We have a way that it’s done here, and we want people to follow that.

Are there common traits of people who succeed in your field? 

Kevin: They have no life, no relationship [both laugh]. 

Cass: You have to be really committed. It’s not a 9-to-5 job. In the early days, if we tell you to come in on Sunday and spend six hours taking clicks out of a vocal then unfortunately you do it. We kind of expect that. We work everyone really hard. But we do reward our staff—I’d say really well. 

Kevin: No one’s gonna walk straight out university or off the street and get this über job mixing top-10 records. It’s a process. It takes time. Part of that is just exposure to music, exposure to the business.

Cass: It’s like with Matt, one of the engineers here, he’s got fantastic clients. We had Skrillex down here.

Kevin: He’s doing all the Chris Lake stuff. He’s taken Fisher… 

We all love it when you’ve got an artist who you really like, and they’re sending you text messages saying, “This track sounds amazing!” That’s the best feeling in the world.


Could you give us an overview of how you arrived at the place where famous artists are texting you? 

Cass: We were in the right place at the right time. We started in the mid-‘90s. Dance music was big but nothing like it is today. A dance record in the charts was a bit of a novelty. It was an underground thing.

Kevin: Some records broke through but it still wasn’t mainstream. 

Cass: It was the time of huge CD sales.

Kevin: We both worked for traditional mastering studios. I started at this place called Tape To Tape, where I met Cass in ‘99. This was when the CD mix compilation was king. We were all DJs. We all made tracks. We were all kids who were into house music. We ended up mixing these compilations for Telstar, Virgin and Ministry Of Sound. We did that for years there. I would work 28 or 29 hours to get one of these CDs out the door. It was savage work. 

As well as doing the branded ones, I started doing mix CDs for Frankie Knuckles, Sandy Rivera, Kevin Saunderson, Paul Oakenfold. Paul Oakenfold really gave me a big change because we’d been doing these DJ mixes and in the process we’d have the beats from one track and an acapella from another. He’d go, “I wanna play that out. Can you tidy that up a bit and let’s make a bootleg out of it.” So suddenly, as well as doing compilations, we started doing mixing and production for some of these guys. Stem mastering didn’t even exist back then, no one talked about it or had heard about it.

Then one day Sandy Rivera rocked up with his Pro Tools rig, and was like, “I don’t want you to master my album, I want to mix my album with you. So we’ll go into the mastering but we’ll do it from my Pro Tools rig. We’ll make changes as we’re going along.” And it just really organically changed into this thing where suddenly rather than just doing mastering, we were doing mixing. 

Cass: We were the younger engineers. The older engineers were still doing the big albums on analogue equipment and dance music— 

Kevin: —dance music was beneath them. We were hungry. We loved the plugins. 

Cass: All the technology was being pushed forward in dance music. Suddenly you had Fruity Loops, Reason, Acid. We adapted to that. The whole industry started to change with Napster and downloads and suddenly CD sales declined. So these big studios suddenly declined and we realised that we were never going to work our way up to these top rooms.

Kevin: We jumped ship literally just before that happened. There was no longer that ladder to climb.

Cass: So 20 years ago we started a small studio. A small room and some PMC speakers. We had some nice outboard kit. We took Ministry Of Sound, Telstar and Defected with us. 

Kevin: I think the biggest one for us was Defected and Simon Dunmore. I’ve now done basically every release on Defected since DFT 004 or 005. So that carried some weight. 

Cass: We did all the Ministry Of Sound albums. It takes a long time to do these mixes. Tracks would get cleared at the last minute. But we always accommodated their deadlines. That makes a big difference when you’re reliable and you always turn things around. Then off the back of that we picked up clients, some big, some small, and it just escalated from there.

Kevin: But really, really escalated when Swedish House Mafia came on board, and with EDM. 


What was the vision for the studio? 

Kevin: Sound. Sound. Sound. No compromise. Amazing studios. And then we just handed it over to these architects. We had an amazing company that built this place. We had a few ideas about how we wanted it to look. Mark Russell from Recording Rooms basically designs and builds studios, and then he puts out the look to architects. He found a young couple who were just leaving a big company. They were really hungry and wanted to put their stamp on a project. We just let them run riot and basically picked everything they said.

Cass: We wanted an industrial aesthetic because it’s a big, empty warehouse. 

Kevin: We said to Mark in our brief that we wanted it to look like there were three studios just dropped by aliens in a warehouse. Everything normally is all squared off and hidden, and we just wanted to be brutally honest about these massive concrete boxes. Let them be the selling point of this place. 


Could you define what you both do at this stage in terms of mixing and mastering? 

Kevin: All I do now is mixing. I had to stop doing stem mastering because where does that stop and mixing start? 

Cass: That’s what it boils down to because if you have an instrumental and an acapella technically that’s mixing. Stereo mastering is with a stereo file. So if you have more than one file, it has to be mixing. 

Kevin: I took on a manager. I started getting royalties and contracts for mixing, and then people would say, “Oh, I don’t want a mix, I want a stem master.” And it’s like, “You just don’t want to pay my royalties.” That’s when I had to say, “It’s either a mix or nothing.” Cass does tons of mixing but they probably call it stem mastering. 

Cass: I was working on a track today, and I took all the drums apart, I put in new drums. So that’s production. I’m not particularly bothered about a production credit, I’ll just do what’s right for the job. 

Kevin: We just want to get songs where they need to be, and you could call it different things. 

Cass: I work on an hourly rate… But the point I’m trying to make is that some people might call it a stem master, because it’s a handful of stems and you do very little to them. But with other things, it’s over 100 stems and you’re doing vocal production and adding new percussion parts, and then you’re really deep into the track. And that’s really what Kevin does on a day-to-day basis. 

Kevin: I think that the line changes when you work for a flat fee and royalties, over an hourly rate. That’s how a record company sees the line changing. That’s why Chris Lake and Fisher have been taken on by other engineers here because their stuff doesn’t need a mix. But they want more love than standard mastering. So it fits in this sort of grey area. They’re not going to give me royalties on a song that maybe needs some clicks taken out of a vocal, handling four or five stems. So where Cass does everything, I only do mixing. 

Basically I met someone at the Grammys who said, “This is insane. You’re mixing and not getting royalties. Would you like me to be your manager?” It was literally a chance meeting, and he changed the industry’s perception of me as a mixer rather than a mastering engineer. 

I think stereo mastering is becoming more and more redundant. Which is why I think we’ve been successful. We’ve changed with what the market needs over time. Back in the day when we started, the only way you could make a stereo master was in a big studio because you needed all this mad equipment. Now there are so many bits of software that do it, there are so many things that can do that well. So the need for stereo mastering became less and less. 

What processes fall under the umbrella of stereo mastering? 

Kevin: It’s EQ, compression, limiting and maybe a bit of width.

Cass: You’re adjusting the sonics of a track. Quite simply, if there’s not enough bass, you put some bass on it. If there’s not enough treble, you put some treble on it. If there’s too much mid-range, you cut the midrange. You’re quite limited with what you can do with a stereo master.  

Kevin: I think mastering was way more important when people consumed albums, listened on CD from start to finish, because then you were tying this body of work together. You might have different mixes from different producers, and you were trying to make it feel like this cohesive thing. As soon as streaming started, no one listens to an album like that and albums aren’t even mastered like that. Every time a single comes out, it’s mastered. And then at the end, they do six more tracks—bang, an album. Now mastering for me is just making stuff really loud but not sounding bad. That’s good mastering: making it loud but still open and punchy in a club.


Could you talk me through the typical process of mixing a track? 

Cass: I listen to the track in its current state a couple of times and just get a vibe for it, and ask myself, what does it need? Sometimes, if it sounds OK, you don’t want to start digging into it too much and changing everything, taking away from what it was. Other times, the kick might be wrong, it doesn’t work with the bass. 

Kevin: What is the point of this song? Is this a really emotional song? Is this a really banging song? Is this a really funky song for radio? What’s the intent of this song? So as I’m setting up a mix, which can take up to an hour, I’m literally looping that song round and round and making all these decisions about what I want to do with that song. If it’s a real dance track the first thing I’ll go for is kick and bass. Nothing else matters in a club. People will dance for five minutes to a kick and bass if it’s right… You can then go in many, many different directions. But if that’s wrong, it doesn’t matter how good that vocal is.

Cass: I’ve got a big collection of kicks that I use on certain tracks. If I listen to something like this track I’ve done today and the kick just doesn’t work, I know I can find exactly the kick that’s gonna sound great. 

What’s next in the process? 

Kevin: The last thing I ever look at is vocals. 

Cass: I’m the same. I’ll look at the main synth or piano, the big lead sounds. Then there are background sounds that maybe aren’t that important. 

Kevin: Make it work with the fewest key elements of the song, get an amazing vibe around that then everything else can just be sort of slotted around that. And I save vocals until the end because they’re a really big part of it, they take the most amount of time, but first it’s got to have that foundation of something great. 

How does it work once you have a draft for the artist to listen to? 

Kevin: A “version 1” goes back to the record company or the artists. They sit on it— sometimes not for very long, sometimes for weeks, and then come back with any requests for changes. Hopefully not many but sometimes millions.  

Cass: We love the ones who go, “Turn that sound up 1db. Turn that sound up 2db. A bit more tops on the vocals.” Very specific in what they want. But sometimes they’ll just say, “Make it more vibey.” [laughs

What advice would you give people to get their stuff sounding as good as possible before it’s sent for mixing or mastering? 

Kevin: Be really honest about your sound. If you think you’ve invented a sound that is better than everyone else you probably haven’t. There are always these songs that just kill everything else in a club. That’s your benchmark. You have to be absolutely critical and listen to yours against that. Listen in every car, on a phone, on everything you can. And just be brutally honest.

Cass: The more you produce, the better you’ll get. You’ll pick up more tricks and tips. We’ve all got clients where you can hear their productions improving over the years. But if you’re not the greatest songwriter then maybe go work with someone who’s more musical. It’s always great to collaborate with other people. 

Kevin: There’ll always be someone who wants to do the bit that you’re not good at or don’t want to do. Some people love the writing but just don’t want to slave over what they would consider the dull bit. But there’ll be someone else who thinks the dull bit is the most exciting bit. 

Records tend to be a collaborative process. Some people, like Amon Tobin, people like that, can do it all themselves. Not everyone can do it themselves. It’s very rare. So be prepared to outsource, and it doesn’t have to be for big money.


I of course noticed all the outboard gear in the studios. What percentage of what you use is hardware vs. software? 

Kevin: All software. We do everything “in the box.” 100%. And we have done so for almost 10 years now. 

Wow, OK. So the stuff in the studios…?

Kevin: It’s all bullshit [laughs]. It’s not bullshit, we didn’t put fake panels in the racks. We owned the equipment when they were better than plugins, but plugins are better now. For me, the desirable nuances of our Manley equaliser are far outweighed by my software Manley equaliser. I can have 10 of them, and I can automate it. I’m changing release times on limiters and compressors with automation throughout the track. You can’t do that with hardware. 

Virtually every bit of kit that I own I’ve got a software equivalent. In my studio we’ve done so many tests between hardware and software with my insane speakers . If I’m sitting in my room quizzing which is which, I think it’s close enough.

Plus if someone calls me up and says, “We need this version of that with the lead taken out for a PA performance tonight,” I gotta be able to just hit save and jump into a new project. I work on multiple mixes at the same time, which I find amazing because it keeps my ears fresh. You can’t do that when you’ve got hardware set up and you’re taking your Polaroids to make sure your settings can be the same when you come back. 

We’re unashamed about using plugins. But at the start it was almost a bit of embarrassment, and your clients are going, “I can really hear your analog equipment.” And you’re saying, “Err yeah, sounds great, doesn’t it?” [laughs

So the speakers, really, are the crucial element of your setups? 

Kevin: And a nice converter, so you can hear what’s coming out of the computer. Oh and a nice volume control. But after that it’s all just things that allow you to hear what you’re doing. There’s no point having this amazing compressor or amazing EQ if you can’t hear exactly what it’s doing. People ask which compressor they should buy, and it’s like, “Spend some money on your room!” That’s so much more important than getting a compressor. An Ableton stock compressor is absolutely fine if you know what you’re doing with it. 

So you think there are myths around the gains that can be made with expensive gear? 

Kevin: When we were kids making tracks, we were like, “Ah the Chemical Brothers use that compressor, I’ll be like the Chemical Brothers if I just had that compressor!”  

It’s curious isn’t it? It’s almost like a consumerist drive. “If I just get that I’ll be happy.”

Perpetuated by all the sound magazines. It’s this thing that this person uses. I’m sure the gear is wonderful but it ain’t gonna make you that person. You’re better off keeping what you’ve got, what you know, and learning the shit out of it. Don’t have 50 reverbs, 50 EQs, they all do the same kind of thing. They’re all the same whether it’s got a slightly different pretty interface on it or not… 

But I say this with great certainty after many years of buying lots of kit and chasing that dream. We’ve all done it. We’re not above that.

It’s also not like a normal listener notices this stuff. 

Cass: It’s snobbishness.

Kevin: Absolutely. And it’s definitely perpetuated by the older generation that haven’t embraced new technology. We hear kids that make the most insane-sounding records with literally Logic and no third-party plugins. It’s what you do with what you got, not what you’ve got. So I’m a huge advocate of less is more.


Are there any projects you’ve worked on that you’re particularly proud of? 

Kevin: I mean, my Kenya Grace number one, “Strangers,” last week. Purely because I’ve worked directly with her in the studio. No record company involvement. Me and her, no producers, no writers. That’s how it should be. That’s how you make music. 

And I would say that the Avicii album I did after his death, that was an amazing project to be a part of. To be entrusted with that by his dad. To work with those producers. And again, no record company involvement because it was just the estate saying, “We know you’ll be respectful of his work. Do what’s right.” I think the less involvement I have from a committee the more I like it. That’s not how you make art, by committee. 

Cass: I’ve just finished the second CamelPhat album. I’ve worked with them for eight years and they’re just really nice guys and I absolutely love the music.

Kevin: When you become friends with the artist that changes everything because now you’re doing stuff with your mates. 

Cass: They are great songwriters, really good fun to work with. They pick great sounds. Everyone wants to sound like CamelPhat, that kind of proggy sound.  

How about challenging projects? 

Kevin: Working with artists where it’s so and so featuring so and so X so and so. When you’ve got four artists and four lots of management and maybe three record labels involved—that for me is challenging. When they want a mixdown and a week later you’re on your sixth set of vocals and the third different singer, that’s the most challenging. 

Cass: I’m doing a big collab at the moment. One of the artists loves version 1. The other one loves version 5. And the first artist hates the v5!  

There are some people who like stuff quite open and dynamic. And other people like stuff pushing in your face. There’s no right or wrong. It depends what you like. 

You’ve worked on so many massive tracks. Can you usually tell when something is going to be a hit? 

Cass: No!

Kevin: We get it wrong all the time. There’s songs that I think, that’s going to be massive—

Cass: —and they sink without a trace. 

Kevin: Then there are other ones where I think, yeah that’s alright, and they become huge. So I am absolutely no A&R man. I mean, “Head And Heart” by Joel Corry and MNEK. Everyone said, “That’s a big song.” And yeah, I knew it was a big song. But no one knew it would be that big. If they said they did, they’re liars! 

Looking to the future, do you still have aspirations or milestones that you want to reach? 

Kevin: We’re training the next generation because we don’t want to be here 70 or 80 hours per week. 

Cass: We’ve put a hell of a lot of time and money into this business and it’s been great but it takes its toll. 

Are you still working crazy hours? 

Kevin: Most days I’m in by 10AM and I can’t think of a day that I’ve left before 9PM this year. So that’s a lot of hours each week. I never worked weekends. I’ve got a family. We have clients from all over the world, so when you’re finishing in Europe people in LA are just getting up. 

Cass: By the end of the week you’re exhausted, it really catches up with you. I love it here. I love the job. I love the people, the space. But it is still work. 

Kevin: Aside from that, I’d like to win a Grammy. I got close with the Fisher project. I’d like to win one so I can take that to my grave [laughs]. That’d be nice, to get some sort of validation. 

It’s something even a layperson could understand the significance of. 

Kevin: Something my mum and dad could be proud about. I did some mixes for Gary Barlow and mum knew who he was. Normally you get, “Who do you work with?” You say Swedish House Mafia and if you’re not into dance music you probably haven’t heard of them. It’s nice doing all the things that—God bless her because she’s not around anymore—but things that your granny has heard of.

Text: Ryan Keeling