It’s the reflections that make the sound in the recording sound so different. And a similar effect is at play in a concert hall. “Improving the acoustics is a matter of getting the right mix of direct sound and reflected sound, especially the first reflections,” says Lund. First reflections are the sound wave that bounce off a surface just once before they reach you ear. Sound waves that hit several surfaces before reaching you are known as reverberation.
The trick is getting the right amount of early reflected sound from the right directions without too much reverberation. Too many strong reflections confuse the brain's processors and you can’t figure out from where the noise is coming – or where the tiger is in the forest.
The problem of reverberation is exacerbated by the fact that direct sound waves tend to run out of puff (and hence can’t be as well heard at a distance) relative to reflected soundwaves. The level of reverberation tends to stay the same regardless of where you are in the hall – and if you’re seated up the back it can even overwhelm the direct sound and first reflections coming from the stage.
The changes to the Concert Hall are designed to do two main things – get sound back down to the orchestra so players can hear themselves and each other, and get more first reflections into the stalls and up into the circle. The results of the tests in late 2016 will be comprehensively studied before work on the Concert Hall begins in earnest in February 2020. The works are expected to take up to two years.
Feedback to the testing of the prototypes from players in the Sydney Symphony Orchestra has been encouraging. Chris Tingay, a clarinettist, said he could hear other parts of the orchestra better than ever before.
“It’s the biggest change I’ve had in 24 years of playing with the orchestra in this hall. I think the orchestra will improve as it learns to play with a new acoustic.
“It did occur to me that the really great orchestras in the world, they have really great halls. If you look at the Concertgebouw in Amsterdam or the Musikverein and the Vienna Philharmonic Orchestra. They have amazing acoustics to play in. I wonder whether the better the hall, the better the orchestra.”
For Lund, who’s refined his knowledge of acoustics from years of experience, what he wants audiences to feel when the Concert Hall reopens is very easy to explain.
“During the rehearsal I spent a lot of time moving around different seats. I was in 30 different positions around the hall, through all four concerts with Tchaikovsky and Mozart. And I think it was the second concert when I leaned back and just enjoyed it. That’s what I would like people to do. I want people to sit back and think wow, it really sounds good. The quality of the acoustics won’t be for a specialist to hear. It will be for anyone to hear that they’re really improved.”