By Arthur Lewis-Nunes

14 December 2015

Tucked away in a forgotten corner of the sprawling Alexandra Palace complex lays a forgotten treasure.

Eighty years ago the curtains in the grand old Victorian theatre came down for the last time, leading to a long period of neglect. Now it is to recieve a new lease of life, thanks to a major Heritage Lottery funded renovation project. This will bring it back to use as a multi-purpose performance venue.

In the Max Fordham Acoustics team, we have been helping to tackle some of the interesting acoustic challenges this project presents.The auditorium has epic proportions that are responsible for impressive reverberation – it takes over two-and-a-half seconds for loud sounds to die away. While this helps make the space highly atmospheric, it presents a major problem for speech intelligibility – an issue widely reported by the theatre’s past audiences.

We have been working to develop a solution that willl enable the acoustics in the theatre to be transformed at the touch of a button. Sound-absorbing fabric blinds on motorised rollers, located in the roof void, will drop down to line the walls, through the gap around the perimeter of the historic ceiling. The heavy wool serge fabric will soak up excess sound, cutting the reverberation time (to just over one second) and greatly enhancing speech intelligibility. Another key part of our strategy is to extend the stage out from behind the proscenium arch. This will address the issue of sound getting stuck in the volume of the stage house and never reaching the audience.

The beauty of using the aforementioned motorised acoustic banners is that it allows all of the modern acoustic treatment to be effortlessly concealed, returning the space to its former ‘as-found’ appearance.

One problem the Victorian designers of Ally Pally didn’t have to worry about was aircraft noise. Now the site is directly under a flightpath, and the lightweight roof does little to keep the noise out, as is required to create an immersive theatre experience. In addition to the requirement to improve its sound and thermal insulation, the roof also needs to support new trusses and theatre lighting. A highly coordinated approach with the structural engineer and theatre consultants was required to develop a solution which provides maximum acoustic benefit for the minimum amount of additional weight.

With construction due to start in early 2016, it shouldn’t be long now until audiences are once again being entertained in the Alexandra Palace theatre – this time in a fantastic sounding space!