Whangarei quarry rocks to revolutionary beat

As a sound machine, it's a little hard to explain — but its inventor says people don't have to understand how something works to have fun.

Not that techno upcycle artist, sculptor and robot repairer Robert Carter thinks there is anything complicated about his pedal-powered sound machine, dubbed the Dub Cycle.

It is a great name for an instrumental machine that generates dub beats, or perhaps it's trip hop electronica, or a trance-ish cross between Massive Attack and the Dr Who theme.

Dub Cycle comprises three found-on-roadside exercycles connected to an amplifier and speakers, one wired up to produce drum sounds, one for the ''cowbell'' and the third for the drone. Green and red buttons on each exercycle's handlebar adjust the sound modulation.

The more pedalling, the more beats per revolution.

''That's how exercycles work,'' says Carter, although in this case it applies not just to heartbeats.

''Everytime I do one rotation it knows, there's a sensor ticking, it makes the beat.''

He is explaining this during a demonstration at the Quarry Arts Centre.

He and two other cyclists on this Tour de Quarry, volunteer Ellenor Pryor riding the cowbells and the Quarry's manager Bronwyn Dalley on the drone, are pedalling up a unique musical composition, with Carter the conductor.

''Faster. Push the green button. Where's the cowbell? Here we go. There! Did you hear that cowbell come in? A bit more drone, please.''

It's one of the week's hottest days. Under the blazing sun, they're pedalling their hearts out, having a three-person rave party, and raising a sweat.

''Now all Rob needs to do is wire up a water sprinkler that runs off one of these,'' Dalley puffs, as her exercycle drones on.

Carter's Dub Cycle will be among interactive demonstrations at the Quarry's open day tomorrow and he looks forward to people sharing the music-making fun.

A range of artists will show their work and open their studios on the day, which promises to provide unique Christmas gifts for sale as well as a range of entertainment.

Carter has had a studio there for three months, where the ''inter-disciplinary'' artist creates a range of technology-based artworks, mostly using cast-off items.

Although he went to university and later to art school, ''I really didn't learn this kind of thing there.''

He describes himself as self taught, having played around with technology and electronics since he was a young kid. Now he's an old kid, still playing with techno toys, as is fitting for an inventor with a sign on his studio wall advertising ''robot repairs''.