Tackling Cinema Reverberation Time

November 25, 2013

Floorscan have been working on and off all year for the Crosby Plaza Cinema on a programme to improve the acoustics within the building across the 3 screens.

The Plaza cinema in Crosby, Liverpool had experienced problems with sound leakage between its three movie theatres. Clearly this can be a real distraction for the audience. One needs only to think about a romantic moment in one theatre being interrupted with loud laughter from a comedy next door to understand how the cinemagoers’ enjoyment would be disrupted. Many modern multiplexes have proper acoustics and sound proofing built in, but when classic movie theatres were built much less was known about the science of cinema acoustics.

Tackling the sound leakage first

The first stage at the Plaza was to tackle the problems being experienced with cinema soundproofing in the building. This was achieved by installing a system of independent wall linings on the outside wall of the two smaller theatres. The frames were then filled with sound absorbing material, covered in an outer shell and painted to match the main auditorium colour scheme. More acoustic absorption materials were installed behind the screens. The cinema soundproofing phase was a success, with staff reporting a distinct performance uplift.

Getting the cinema acoustics right; tackling cinema reverberation time

The next stage was to work on improving the overall cinema acoustics in the main theatre and specifically the cinema reverberation time. This is especially important in cinemas, where too much reverberation can significantly decrease the clarity of the film’s soundtrack.

Getting the cinema reverberation time right would improve the cinema-goers’ experience of the film and also let the soundtrack be heard the way the director intended. Extensive testing revealed an issue to the rear of the main screen and a bespoke acoustic absorption unit was designed and installed. Special Sonata Aurio absorbers were also installed onto the walls inside the mini theatres to either side of the main auditorium. Although the sound quality is vital, cinema is clearly an experience that involves other senses too, so the units were colour matched with the cinema’s branded seats to achieve a pleasingly coordinated look. The atmosphere of the cinema is also important, so special acoustic doors have been built to reflect the Plaza’s Art Deco interior.

Experiments with movie sound quality

The effect of cinema acoustics in delivering a high quality movie experience cannot be overstated. In fact, experiments have shown marked differences in the way a film is interpreted when viewed in theatres with different qualities of sound systems. In one study, a sample group was divided into two groups and shown the same film, ‘Six Degrees of Separation,’ which is rich in dialogue. The group that was shown the film in good acoustic conditions stayed attentive enjoyed the movie and could give an accurate account of the storyline. Some 70% said that they would watch the film again. The second group, shown the film in poor acoustic conditions, were not able to give a good account of the story and none wanted to see it again. Interestingly neither group mentioned the sound quality, which only shows how cinema acoustics can affect enjoyment even subconsciously.