Grieghallen – renovated acoustic celebrity

It could have gone very badly. The structure of famed Danish architect Knud Munk was basically unsuitable for song and music – his dream of a Roman atrium cannot be easily combined with beautiful symphonies in rainy Bergen. Salvation came in the form of Director of Research Helmer Dahl from the Chr. Michelsen Institute and the fact that funding problems delayed completion of the concert hall.

Grieghallen – renovated acoustic celebrity

"Grieghallen isn't that empty when you let a Norwegian composer in. – Follow my gaze, and you will see the full Philharmonic Orchestra and its conductor working on one of my pieces." Harald Sæverud

Harald Sæverud composed a special piece for the opening in 1978. The text below this photo was written by Sæverud himself a few years after Grieghallen opened. The photo was taken by Erik Eknes, Helmer Dahl's right-hand man during the Grieghallen project. Sæverud listened to the Bergen Philharmonic Orchestra rehearse his new piece before the opening of Grieghallen, and Eknes took this photo.

"Coincidentally, Sæverud's son Sveinung was our daughter Marit's piano teacher. Anne-Sofie, who found this photo, and wanted to keep it in her press clippings book for Grieghallen, asked Harald Sæverud to sign the photo, and this is what he wrote," says Eknes, who spent large parts of his days at the concert hall from 1976 to 1978. This was necessary in order to make the hall good enough to enjoy music.

The Grieghallen Project

Let's go back to the early days of the building – the 1960s and 1970s. Hundreds of years fighting for a concert hall in the city were coming to an end. The building was designed and the frame was built, but then the project came to a halt. The shell stood empty for five years. However, one person with a positive attitude towards the project was Helmer Dahl. CMI's Director of Research, who was responsible for ensuring that the acoustics in the theatre were good enough for the Philharmonic and the royal guests of the Bergen International Festival would take advantage of the time to ensure that the building was perfect for sound and music. Helmer joined the construction committee in 1963.

 

Grieghallen and photo of the interior of the shell and scaffolding, taken in the seventies. (Photo: Erik Eknes)

 

Quote from Dagbladet, 7 February 1974: "Grieghallen was meant to be the pride of Bergen culture, but for years has been a symbol of Bergen's megalomania."

 

The lack of funding that delayed completion had a positive impact on the acoustics at the concert hall. (emphasis)

In the board's reports to the Institute, Helmer Dahl clearly stated it was good that the construction of Grieghallen was delayed. This gave him the chance to obtain enough knowledge to get the acoustics right.

Helmer brought in the best experts in the country, and they looked for solutions to improve the concert experiences of the people of Bergen. They visited opera houses and centres of expertise around the world: England, Japan, Salzburg, and naturally also the new Oslo Concert Hall.

"But there was little to be gained in Oslo," says Erik Eknes, Helmer Dahl's right-hand man at the Chr. Michelsen Institute:

"I went to Oslo with Helmer, project manager Finn Sandrup and an electronics expert. The plan was to gather information in different fields. We all agreed that we wouldn't use the same solutions they had chosen," says Eknes.

Helmer Dahl and Erik Eknes inside Grieghallen 1978. (Photo: Jan M. Lillebø, BT)

This view was shared by Professor Asbjørn Krokstad from the Norwegian Institute of Technology. Eknes explains that he attended an acoustics conference in Sandefjord, and when the Danish experts talked about the Oslo Concert Hall, Kroskstad stood up and said something like: "I can't understand the use of money at the Oslo Concert Hall. From a professional perspective, it's absurd." (Eknes' recollection of Krokstad's statement).

Eknes explains how also the Oslo Concert Hall's auditorium was later fixed to get the acoustics right.

The visit to the BBC was also illuminating.

 "Helmer had good contacts in England, as he had worked there during the war with Professor Appleton and designed the radar systems that wiped out the German submarines. He got straight to the top of the BBC. When they unfolded the drawings, their head acoustician shook his head and said, 'This won't be easy.'" (Source: Eknes and quote from a lecture by Erik Eknes, Nordic Acoustics Symposium, Bolkesjø, 25–28 October 1979)

New drawings were needed. "Things got heated during the construction meetings", says Eknes, especially in the early stages of the process, when Svein Strøm of the Norwegian Institute of Technology informed Munk that the saddle roof and walls needed to be altered.

"Sandrup clearly told Munk to return to Denmark and devise new drawings. We didn't see Munk any more after that, but we worked with an incredibly clever young Danish architect/artist from Munk's office during those last two intense years," says Eknes, and adds, "Our communication with the young Danish architect was very good."

Munk had also drawn simple lightweight doors, and refused to do anything about them. Everyone understood that they wouldn't work in an auditorium, and facing a very busy street.

"That's when Helmer asked me to draw the doors the way we wanted them to work, but for the drawing to be so ugly and lumpy that Munk would get the point."

"We got what we wanted, and the result works."

There was an item on the Stockholm Concert Hall at a later Nordic Acoustics Seminar. It had been renovated after many years' use, and great modernization was required. The lecture was very interesting, and Eknes struck up a conversation with the people in charge, and he, Helmer and the Grieghallen electronics consultant were invited to Sweden. They received many good tips, and they returned home and changed many of the electrical plans for Grieghallen.

Read more about technical facts in Applied Acoustics 1985

Missing pipe trenches


Grieghallen 2015: Rolf Skogstrand and Erik Eknes meets again. (Photo: Gunn Janne Myrseth)

Rolf Skogstrand events manager at Grieghallen takes Erik Eknes on an inspection. Erik has not been here for many years. The memories come flooding back, including about the laying of cables in non-existent pipe trenches. Luckily one of the sound boys was small enough to squeeze into the floors. Eknes also remembers the rostrum for King Olav: "It was made for the formal opening of Grieghallen. When we tested it the night before the opening, a very unpleasant noise came out of the speakers. After a thorough search, we had to give up and place a temporary solution (microphone stand – Ed.) in front of the rostrum. We later learned that the rostrum had been placed over the emergency power supply below the floor."


Inside Grieghallen in May 1978: To the left King Olav at the new rostrum. To the right The King and his son and his wife, later on they became King Harald and Queen Sonja. (Photos: Erik Eknes)

 


Inside Grieghallen the night before the grand opening. A  guitarist in an empty auditorium. (Photo: Erik Eknes)

The sound man (Erik doesn't remember his name) sat in the middle of the auditorium the night before the opening and tested the sound by playing a guitar solo. “That's when we agreed that this was going to work," says Erik.

New seats

Time has passed since 1978, and the seats were worn. The same was true of the floor and other elements that needed to be modernized. For Skogstrand, who worked at Grieghallen in 1978 and still works there, also the renovation project was nerve-wracking: "We did not want to destroy the mood and our acoustics. The work performed by Erik and his colleagues back in 1978 provided the foundation for what we had become."

Grieghallen hired the foremost acoustics experts in the country, Brekke & Strand. They also felt a sense of reverence.

Magne Skålevik, Brekke & Strand, confirms this: "To the best of my knowledge, the 1968 article in the Journal of Sound and Vibration is the most-quoted article ever from the Norwegian Institute of Technology/Norwegian University of Science and Technology," says Magne Skålevik.

QUOTE emphasized: "The 1968 article in the Journal of Sound and Vibration is the most-quoted article ever from the Norwegian Institute of Technology/Norwegian University of Science and Technology" link to PDF article ("Calculating the acoustical room response by the use of a ray-tracing technique ..." (1968) by A. Krokstad, S. Strøm, S Sørsdal, J. Sound Vib

Abstract : "The distribution of early reflected sound over the audience areas in concert halls is investigated, especially with respect to the shape of halls. The study is based on geometrical acoustics, using a ray tracing technique. The sound intensity is calculated by digital computer, and a graphical representation obtained. Test results for a rectangular and a fanshaped hall are given."


Erik Eknes tries the new seats in 2015. (Photo: Gunn Janne Myrseth)

In 1983 new facts was published: "Fifteen years’ experience with computerized ray tracing", by A. Krokstad, S. Strøm, S. Sørsdal:

Skålevik was one of Professor Asbjørn Krokstad's students at the Norwegian Institute of Technology, so he took a reverent attitude towards renovating Grieghallen in 2012. The work of CMI's Helmer Dahl and Erik Eknes, with expert contributions from Svein Strøm and Asbjørn Krokstad of the Norwegian Institute of Technology, is well known in Skålevik's circles.

This was the first time they used computer simulations to help construct a concert hall as large as Grieghallen. Mathematical formulas, sound and light simulations the like of which had never previously been seen were used here. This is documentation that is still useful for researchers around the world as a learning resource. Strøm, Helmer and Krokstad used computers or electronic data processing as it was called at the time, to perform advanced ray tracing.


In light of the era and the basis provided by the architecture, Skålevik believes that the auditorium gives listeners a good experience. "The fan form is not a good auditorium shape. To achieve enough side reflection to give the music depth of acoustics, you must build using rectangular forms to give the auditorium a shoebox shape," says Skålevik.

With Skålevik about to fix what in principle is a cutting-edge job carried out within the frames of the building's construction, all of the old documentation was dug out. Every detail about seats, walls, wall panels and all the material used in the hall was analyzed. The drawings and the 1978 article in Applied Acoustics (Dahl, Krokstad, Strøm, Eknes) were particularly useful.

"The seats that had been originally installed and were now going to be replaced were custom-built. Every aspect of them was charted, and compared with the seats from 1978. This is a conservation project," points out Skålevik.

However, in modern eyes, Grieghallen is not among the best concert venues. "The auditorium projects too little early lateral sound. The sound level in the auditorium declines as you move away from the stage and up," explains Skålevik.


Erik Eknes and wife Anne Sofie with collegues celebrating Grieghallen in 1978. (Photo: Erik Eknes collection)

For two years Erik Eknes spent large parts of the day in the concert hall. His wife Anne-Sofie Eknes made her own press clippings book; a book that now allows us to look at the history of the concert hall through the eyes of newspaper articles.

Helmer Dahl

Helmer Dahl worked with acoustics in Grieghallen for over 15 years. He joined the construction committee in 1963. He was never paid for his work for Grieghallen. As he wrote in CMI's 1978 annual report: "... this was part of my work as a member of the Chr. Michelsen Institute, and which is why my wages were never charged to Grieghallen. This means that CMI made a substantial contribution to the erection of Grieghallen. My workers' time and expenses were treated as a regular engagement."

"But it was difficult to predict that the ceiling of the auditorium, which had a budget of NOK 2 million would finally cost NOK 6 million. Neither was NOK 11 million in overtime budgeted for. A building's progress plan is normally adjusted two or three times during the construction period. On this project, it was completely reworked about twenty times. This gives an idea of how difficult and demanding the Grieghallen project really was." (Source: CMI 1978 Annual Report) 

On the grand opening to the right Helmer Dahl enjoyed the party with his wife Ellinor, in front. (Photo: Erik Eknes)

 

Link quote BT article BT 26 June 1979:

"Grieghallen is a complex auditorium, but computer technology made it possible to identify a design that created excellent acoustics.

This success comes from precise calculations. And it is computer technology that has shown the acousticians at the Chr. Michelsen Institute what the auditorium needed to look like in order to achieve good results.

The problem was the following: the sound in an auditorium is reflected 10–20 times in the walls and ceiling before it dies down – in reality when it reaches the listener's ears.

Every element in the auditorium must be adapted to achieve an even distribution throughout the whole seating area during the entire reverberation time. Due to the great distance to the walls on the sides, it was particularly difficult for Grieghallen's acousticians to ensure that the middle of the auditorium received good coverage. The sound on every level was ray traced in time, space and throughout the entire seating area. All of the information was then fed into a powerful computer program and finally the dispersal profiles were read and adapted to the hall's construction in order to meet the music's needs for reflection."