They've spent little time in their Brooklyn homes this year, performing to tens of thousands of fans at dance music festivals like Electric Zoo and Paradiso, and embarking on tours that last for months across Canada and America.
Cooper's been so busy he loses track while name-checking this year's best shows: "Las Vegas Electric Daisy Carnival, Paradiso, Seattle, New York, Canada, Washington, all of Texas, Colorado, Denver, Atlanta ..." They've also found time to release EP Walking on Air, finish a full-length album set for release in early 2014, add orchestral elements to their live show, and open for Lorde at her first major New Zealand show back in September.
And they'll be ending 2013 with a summer tour around New Zealand, taking in four beachside spots and a Christchurch show alongside a revolving cast of support acts including State of Mind, the Upbeats, Minuit, Diaz Grimm and Broods.
"It's gonna be choice as. I'm definitely looking forward to the New Zealand summer and wearing my jandals," Cooper laughs. He's not kidding when he says he's trying to time tours so that he spends all year in summer weather.
There'll be two major changes fans will notice from Mt Eden's last summer tour here two years ago: firstly, they've dropped the 'Dubstep' from the end of their name and are now known simply as Mt Eden.
Cooper says he and Rayner wanted to expand their sound beyond the traditional elements associated with the dance music trend that first hit in the late 2000s. But the dubstep tag has been a hard one to shake.
"We're actually stuck with it. As much as we tried to get rid of it, it keeps coming back. I think everyone thought, 'Oh, Mt Eden - it's dubstep' [but] we didn't want to be restricted to that."
That's where the next change comes in: they enlisted string arranger Larry Gold (whose credits include Kanye West, Eminem and Jay-Z) to help expand their sound, giving them 45 minutes of material to perform with a full orchestra, something they'll be doing at their upcoming summer shows.
That's been Mt Eden's reaction to a changing dubstep scene, which has seen audiences tire of the tried-and-true cliches like the gigantic drops, waves of chest-rattling bass and grimy squelches that the genre has become known for.
Cooper says many dubstep acts are instead turning to house music to keep their audiences, but Mt Eden are ignoring that trend, instead concentrating on writing proper songs, adding atmospheric elements and including live musicianship. "A lot of the dubstep acts are jumping ship," he says. "You'll see a dubstep act drop a house beat and it just goes off a little bit more - especially for girls.
"We're getting really musical, playing piano, adding some live elements to it, and using real drums instead of generic dubstep drums.
"Don't get me wrong - I like a filthy drop every now and then, but with the evolvement of dubstep a lot of artists are moving to the dancey house scene.
"We're trying to change it up and [do] something different."
It's a sound that will be explored on their new album, which is finished and just waiting on artwork before being released on Ultra Records - home of dance giants like DeadMau5 and Calvin Harris - in early 2014.
Cooper says it's going to include elements of classic dance music, "moombahton" and more guest vocalists - but one person you won't see on there is DMX after an awkward encounter with the wayward rapper when the duo shared a stage with him in Atlanta.
Cooper declared it Mt Eden's worst show of the year.
"DMX was like, 'Who the f***'s Mt Eden'. We got kicked out of our green room because of him. He had six bouncers around him, plus his entourage, which was insane.
"It was just a really weird show."
It was a rare low point for the band, who have come a long way since Cooper asked his girlfriend's little brother to upload the band's epic first single Sierra Leone on to YouTube.
That song, recorded in his bedroom when he worked as a builder, became a YouTube phenomenon and allowed Cooper and Rayner to quit their day jobs and call Mt Eden their career.
But Cooper admits they're so sick of Sierra Leone they only include snippets or remixes of it live - even though it's a guaranteed crowd-pleaser.
"I've played that song live like 10,000 times. I'm getting sick of it, I'm over that tune. We play a little snippet - 30 seconds to a minute - then fade away."
And Cooper sighs when he's asked what his plans for 2014 are: they're embarking on a North American tour taking in 40 to 50 shows over two-and-a-half months.
He admits that he finishes tours like that feeling "shattered"- and it sometimes causes arguments between him and Rayner.
"We get a little bit moody at times. But we're guys, we just get over it. It's like, 'Sweet as, let's do the show'."
Who: Mt Eden
What: Hard-working electronic duo touring over summer
Dates: Mangawhai Tavern, Dec 26, Coroglen Tavern, Dec 28; Riwaka Hotel, Dec 31; The Dux Live, Christchurch, Jan 2; Waihi Beach Hotel, Jan 5
- TimeOut
