The concept behind ‘drone supergroup’ N + [BOLT]’s “15 Amps” is a remarkably prosaic one, putting their combination of rich atmospheric hums and drones, ambiences, reverbs and guitar sound-shaping into a format that feels quite scientific.

It was originally a live installation performance recorded in 2016, in which each member of the trio could direct their live performance to any combination of five amplifiers each (hence the “15 Amps” total). All the amplifiers were arranged in a circle, as per the cover art diagram, so their individual contributions were evenly distributed. The audience would hear a different mix of these many layers that would vary depending on their position in the room, making each listener’s experience just marginally unique.

Four years on, this recording has now been rationalised down to a stereo LP. For the first side, this is done by simulating a work around the edges of the room, with individual elements slowly rising and falling and taking their turns at prominence. By the middle of the second side, there is more sense of standing in the middle, with a wall of sound coming at you from all sides- a wall which begins to feel more gritty and abrasive over time, but never overwhelming- but this is bookended by a long period of calm on either side, including a very gentle exit indeed.

(Incidentally the LP is split into two sides, but digitally it is available as one single work, just under 48 minutes.)

Musically, it’s uneventful- a steady piece of washing drone full of familiar steady builds and rumbles that feels like a very established sonic format, bordering on formulaic- but mesmerising nonetheless if your frame of mind lets it wash over you.

The press release says that this is the act’s final collaboration with Midira, for undisclosed reasons. Hopefully the reasons behind this are positive and more of this work will not be too far away.