Theatre acoustics: designing drama spaces for speech and music

Turku City Theatre, which was in desperate need of modernization, was completely renovated over two years. The theatre was reopened to the public in August 2017.

Turku City Theatre was built in 1962. It is located in the heart of the City, by the Aura River. Shakespeare’s The Tempest was chosen as the first play to be performed there.

Turku City Theatre has always been a traditional repertory theatre, staging multiple plays on three stages at the same time.

Great Small Stage

The flagship of the contemporary theatre is the Small Stage. It is a 250-seat, "black box" that is highly versatile in presentation technology. The sound technique, lights and acoustics are just as good as they can be. Akukon Ltd's acoustic designer and architect Anssi Ruusuvuori is partly responsible for that.

Mr. Ruusuvuori has always been well familiar with his hometown's venue. His article The new experimental stage of the Turku City Theatre (1999) was published in The Journal of the Acoustical Society of America.

Eight meters above Small Stage's seat level lies a tight steel mesh.
– The biggest benefit of that net-roof is that you can walk everywhere and move your equipment safely. If this space was only equipped with a traditional bridge, it would not be so modifiable. The steel net roof also gives you the opportunity to place the lighting exactly where you want it. No compromising is needed, says Mr. Tapio Ilomäki, a consultant at Akukon's presentation technology.

As the most important thing for Small Stage, Ilomäki picks up the invisible acoustic curtains not shown to the public. All the curtains have been integrated into the walls.

Contractors at each other's interface

When almost EUR 40 million and two years are used for the renovation of a preserved cultural building, it is clear that many contractors are seamlessly working on the site. The list of those taking part extends to several paper sheets.

The contract boundaries were defined in a separate document, and work commentary by Anssi Ruusuvuori and engineer Lauri Vikström from the Turku office of Akukon Ltd described the requirements that need to be taken into account in all such installation work that punctures or immerses sound-insulating structures. Specifically, this involved installing pipes, ventilation ducts and electrical wiring.

The interfaces between presentation technology and other works were carefully examined. Contractors should pay particular attention to the careful carrying out of the work and at several points ask for advice or permission if the execution of the work phase was likely to affect Akukon's acoustical requirements.

According to Mr. Ruusuvuori, the situation was good because "I got free hands as a designer and the customer really had understood about the acoustics".
– The seven-meter-high sliding doors, which were supposed not to leak absolutely any sound at all, really stood out. They were acoustically measured several times, and gradually, adding different structures and fill-ins, all were met to meet the requirements.

Acoustic requirements apply to all devices that cause or may cause noise with sound levels exceeding Akukon's values, or vibrations that may pass through the building's body to other areas and cause noise there.

Special mechanics and fiery presentation technology

The facilities were quite challenging for the AV-designer.
– Very heavy cabling into rather small gadgets' rooms gave us a lot to seriously think about, remembers Mr. Ilomäki.

From the customer's point of view, obtaining the design of presentation technology, acoustics and mechanics from one firm, Akukon, added value. In this respect, the budget remained as planned, and city's decision-makers did not have to worry about the real cost of presentation technology.

Turku City Theatre used to be Finland's oldest municipal theatre. In 2014, the municipal theatre was turned into a limited company. The city now owns 100% of Turku City Theatre Ltd.’s stock.

Partnership rules

The procurement of presentation techniques and mechanics was split into several contracts. The mechanics were operated by Insta Automation, Bosch Rexroth and Raita Katsomot Ltd. The main contractor of the presentation techniques was Bright Sales and Installations.
– They did an absolutely mindblowing good job. Cable terminating, clocking, wireless microphone upgrades, effects output systems, camcorders and monitors, lists Mr. Ilomäki.

Meyer Sound's system for the Big and Small Stage was carried out by Studiotec Ltd. In addition, almost all of Finland's leading importers participated in the delivery of equipment; Equipment Acquisition Program had a total of 4200 actions or devices.

Through Riedel's command system, all stages can be combined, if necessary. The Big Stage audio system is in the theatre world quite rare solution made by AVID.

The rising floor of the stage

The specialty of mechanical design can be found on the ascending floor of the Small Stage. It was designed by M.Sc. Timo Risku from Akumek Ltd as Akukon's sub-consultant.

The floor machinery works with a group of six lower and six upper stands that cover most of the entire stage. The stands can be lifted high, leaving the entire room height between the stands.

All the stands are independently operated, so the group of stands can carry out very diverse runs.

Value yli 30 million ¤
Gross floor area 14 525 m2
Start August 2015
Completion August 2017
Construction period 24 Months
Acoustical designer Akukon Ltd, Anssi Ruusuvuori
Lighting, sound and video systems Akukon Ltd, Tapio Ilomäki,, Juha Storm, Toni Poikonen, Jussi Vartio, Mira Pykälistö
Mechanical systems Akukon Ltd / Akumek Ltd, Timo Risku
Architect LPR-Arkkitehdit Ltd
Project management Skanska Talonrakennus Ltd
Builder's representative Turku municipal property corporation
Builder Turku City Theatre Real estate company

Text: Jukka Sundholm

Turun Kaupunginteatteri 1 big stage

Only a few modifications to the structures were allowed. Still, some new solutions had an impact on main stage's appearance and sound.

Turun Kaupunginteatteri 2 small stage

Small stage's reverberation time can be adjusted by curtains designed by Akukon's Anssi Ruusuvuori. The audience only sees the black metal grille in front of the curtains.

Turun kaupunginteatteri 5 net-roof

The biggest benefit of that net-roof is that you can walk everywhere and move your equipment safely.