Dome of distinction

I was at the Dome at the weekend (O₂ arena to use its corporate title) watching a band that shall remain nameless to preserve a modicum of my street cred — although said band were actually excellent.

Given the fact the dome was an abysmal failure as a conference / attraction centre — and my experience with places such as the NEC and other stadiums have been mediocre at best — I didn’t envision it being much cop as a concert hall.

How wrong was I?

A sound engineer’s dream

Allow me to get all geeky for a moment and put my sound engineering hat on. The stage itself was in the usual location at one end of the oval. A speaker stack thrust sound pressure waves at the audience around the edge of the space with very little perceivable delay between the action on stage and the perception of the sound. Usually there’d be a delay of around 1/8 – 1/4 of a second while the sound caught up or was reflected around the arena in unwanted directions.

In this case the delay was probably close to 1/16th second, which was impressive.

After the support act had left and we were waiting for the main act I did my usual thing: try to figure out how something works. I looked up.

Hanging from the ceiling was a semi-circle of baffling — at about the same distance from the stage as the people in the first set of tiered seating. This I figured was catching the main crux of the sound and preventing nasty reflections muddying the sound space.

In addition, down the long central spine of the roof were an array of fat, higgledy piggledy tubes — each probably about a metre in length. They appeared to be covered in some absorbent material; a bit like thin lagging. While they may have been accidental, functional or structural, they were acting like a giant diffuser and helping to bounce the sound harmlessly away in unexpected directions.

Over one side of the arena — just under halfway along its length and offset from the centre — hung another huge circular speaker array. At sporadic intervals around the periphery (but just inside the semi-circle of baffling) were also hanging a few stacks of three or four speakers.

I suspect — but have no way of knowing — that these additional speaker groups were being used as repeaters (or maybe pre-repeaters / echo cancellation), delaying or pre-empting the sound by a fraction of a second and adding a small amount of music to the overall mix. My guess is this would work rather like the way your surround sound speakers work in your home cinema system, by exploiting the perception of sound in 3D space via alteration of the time sound takes to reach your ears.

Designed for audio

The combined result was like nothing I’d ever heard in a live environment: clean, crisp, tight, perfectly balanced and virtually echo-free sound delivered to all corners of the arena.

Going back to the minimal delay aspect, it also meant a far better experience for the crowd: an example became clear when the artists on stage raised their hands above their heads and clapped in time to the beat for the audience to follow suit. The arena design alleviated the smudged mash of 18 000 people clapping at very slightly delayed intervals as they tried to either follow what their eyes told them vs what they could hear.

I well and truly tip my hat to the team of designers at the arena who were clearly listening that day in Sound Engineering school. You help everyone to rock.

The infrastructure worked too

Not only did it sound good but the arena pretty much emptied in five minutes after the end of the gig. No waiting around for people to mill about or go up and down badly positioned staircases. Nope. Just no-nonsense, well-planned exits and great facilities. We’ll of course gloss over the fact that a small bottle of Coca Cola cost £2.70.

On the whole though, the place is one smooth operation. It’s an amazing venue and you deserve to check it out.

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