History preserved at the Sommerro

A huge refurbishment project in Oslo tasked the integrator with supplying invisible AV to fit with the original 1930s art deco architecture. Paul Milligan finds out how it was done.

Occupying the former headquarters for Oslo Lysverker (the city’s electrical company) Sommerro is the latest venture from Nordic Hotels & Resorts. Situated in the elegant Frogner neighbourhood, the building dates back to the 1930s. The Old Oslo Lightworks once housed the first electricity distribution centre in Oslo, before later serving as the largest indoor pool and spa in the city, the Vestkantbadet. This rebirth features a hub of restaurants and bars, a library, a small private cinema, and the city’s first rooftop pool, sauna and terrace with views over the Norwegian capital.

In a project costing more than 250 million euros, it has been meticulously restored in cooperation with the director of cultural heritage in Oslo. It now features 231 rooms and suites, a full medical spa and pool area with adjoining gym, a rooftop sauna and swimming pool, six restaurants, seven event halls, four boardrooms, a selection of meeting rooms a library, a movie theatre, a piano bar, and two live stages. 

all images: Francisco Nogueira and Chris Aadland


These facilities required an extensive AV system that would remain discreet and maintain the 1930s-style décor. Following a tender process, Oslo-based system integrator Bravo were awarded the project. Once on board, what was the initial client brief to Bravo? “Initially the biggest concern for them was that this is a historic site, there are quite a few restrictions when it comes to the equipment that we could put in there. It couldn’t be very visible, it had to extremely high quality with low maintenance, but the main concern for them was that they wanted to have a modern hotel with all the facilities and nightclubs etc but they didn’t want to see any of the equipment,” says Mikael Osen, CEO, Bravo. The scope of what the client wanted to deliver to the guests was quite wide explains Osen. 

“They have a self-playing Steinway piano playing to two different areas in the hotel, it’s everything from background music all the way through to full-on nightclubs in the same area. They wanted flexibility and ease of use at the same time.”

Both the meeting rooms and larger event and meeting areas in the Sommerro are used for both board meetings and normal meetings, but also a lot of weddings and live eventsin order for those areas to become an extra revenue stream.

Audio for the project was supplied by local distributor, First Audio, and includes a total of 295 K-array products, making the Sommerro project the largest K-array installation to date. The K-array system was chosen for its discreetness and the availability and range of models which could fit the variety of use cases throughout the Sommerro.

The Ekspedisjonshallen restaurant, which offers all-day dining, features a wall fresco by Norwegian artist Per Krogh, so maintaining the aesthetics of the restaurant was the highest priority. The dining hall hosts a live band every weekend, followed by a late-evening DJ, so these requirements were also taken into consideration during specification. Here, the installation comprises ten Python line array loudspeakers and four K-array Vyper loudspeakers, alongside four K-array Rumble and two Thunder subwoofers to enhance the low-frequency range.

The system is driven by a single KA208 Kommader amplifier. The Sommerro also offers an on-site cinema, library room and theatre space. The cinema seats 28 in art deco lounge chairs and offers regular screenings of everything from Norwegian and foreign films to classics. Movies are shown on a 138-in LG LED screen, the immersive audio system supplied here by Bravo includes a Yamaha RX-A8A Musiccast receiver which serves as the central hub, providing connectivity andcontrol for the entire audio setup. The main audio system is comprised of three K-Array Python metre-long line array elements, plus Python half-metre loudspeakers for surround sound.

Amplification is provided by K-array’s Kommander-KA34 and Kommander-KA104. The wellness floor at Sommero, named Vestkantbadet after the public swimming pool originally at the site, is a 1,400-square-metre space comprising an infrared sauna, cold plunge pool and modern gym. Subtle background music is provided here via three K-array Domino KF26 loudspeakers, driven by a Kommander KA14 amplifier, whilst two Spherina Air pendulum loudspeakers provide even sound distribution.

Much of the third floor is dedicated to a series of meeting rooms, audio here is handled by K-Array’s Azimut system, composed of two Vyper loudspeakers, a Truffle-KTR26 subwoofer and a KommanderKA02 amplifier. Audac ceiling speakers and amps were also specified in different areas of The Sommerro, for some of the more architecturally sensitive rooms, to keep that ‘invisible’ look. Control throughout all the spaces in handled by Crestron NVX. Control is handled either by hotel staff in each room via a Crestron touchpanel or on the move using a tablet or phone.

All of the audio is being run on a network over Dante, to give the venue more options says Osen, “It gives them the flexibility, for instance if they have a DJ on the roof and they want to showcase that across the entire hotel.”

Bravo chose ZetaDisplay as the display signage provider for the hotel, and worked with LiveQube on the curated music for the hotel. Bravo also collaborated with a company called Waved, which is an experience platform that can dynamically adjust the volume of the music depending on the intensity of the room. Osen explains how it works; “For instance, if they have an afternoon tea and they want to have that very low key, if the volume gets too high or the music is too intense, they can bring it down to something more suitable.” Bravo chose Sennheiser to provide all microphones in both the meeting rooms, boardrooms and live stages. In some of the larger meeting rooms Avonic PTZ cameras with 20x zoom were installed to offer the option of streaming video around the hotel to different areas or to stream to the outside world. Bravo has also installed a podcast studio in one of the boardrooms, so they can be recorded in high-end style and comfort. The meeting rooms feature a mix of Samsung Flip 3 75-in interactive displays and LG 75-in OLED displays, with Teams video conferencing enabled via a Bose VB1 videobars.

Testing of the AV was done on-site mainly because of time restraints of the project. “We did all of the racks off-site and we moved that into the hotel when we did the final install. We did backend testing, but all of the sound was done on-site. Our window got shrunk as the opening date approached,” admits Osen. 

The biggest challenge for Bravo was the main exhibition hall, with all of the listed elements and acoustic issues within that room, “This was the biggest hurdle we had to get across. We weren’t able to test really anything until opening day, at least not with all of the interiors in place. It was minutes before the first guests arrived.” The room may look stunning, but a mixture of glass and hardwood material meant there was very little there that could soften the acoustics. “It came down to th  placement and the tuning of the system really more than anything else, and also trying to narrow where the sound bounced off from. It was a large tuning job,” admits Osen. 

One of the briefs Bravo had to meet in this project was that the system could be used by anyone. The Sommerro hosts live music every day, and while there is some internal resources to handle this, the day-to-day AV operations are run by general hotel employees. To enable non-trained employees to do this Bravo has provide “a  lot of programming” to make the system as easy as possible to use. “We have a button on one of the control panels which just says ‘band on stage’, with one push of a button it mutes every other audio and turns on the PA and all the lights,” says Osen. To get to this point involved a lot of meetings and discussions with the client to find all the different scenarios it would need and “How they really want the system to perform. That was quite a large job really,” adds Osen. 

Has Bravo provided any training to The Sommerro? “It’s fairly easy to use, but we have different user levels, depending on what you can do and are allowed to do. Some of the super users, when they want to do something with the signage for instance, we work closely with the in-house marketing team to make that as seamless as possible.”

Bravo was involved in the project for six months, with the last 45 days of that period involving the bulk of the installation. How was Bravo able to achieve what it has on this project within a condensed timeframe? “We have often had the experience where we get involved too late in projects, but in this project we got involved well before the concepts had landed from the interior design team (Grecodeco), so we got to have our say along the way. And I think that’s the main reason why this became such a success.” How was it for Bravo working in a listed building where the design requirements could sometimes be restricting to installing AV equipment, and where such a high level of design was the clear priority? “The interior design team understood they had to deliver a working hotel. They knew we had to bring in a lot of AV equipment for this to be a functional hotel. Sometimes interior designers don’t want to have any AV equipment at all, but that was not the case in this instance. They understood that they had to work with us and wanted to find solutions that could accommodate high-end AV equipment. In addition to the nice interior elements that they worked on,” explains Osen.

The hotel officially opened in September 2022, has anything happened since then that Osen didn’t expect? “How much the system is used has surprised me actually, more than anything else. We didn’t want to give them advice and install stuff that they would end up not using. We feared that a little bit in the installation because we delivered so much equipment, but they really utilise everything, and that’s nice to see."


Allen & Heath SQ-5-X digital mixer
Audac Cira 824 ceiling speakers, EPA254, CPA24, SMQ350 and SMQ750 amplifiers, speaker, Noba subwoofer
K-array Kommander KA34, Kommander KA208, Kommander KA14 amplifiers, KK52, Tornado KT2C, KP52, KV52, Python KP102 I, Lyzard-KZ14 loudspeakers, KU212, KS3P I,
KU26, KS2P I, KU44 and Truffle-KTR26 subwoofers
Sennheiser EM 6000-D receiver, SK6000 transmitter, SKM6000 mics
Xilica R22-WP-X and R22-WP-M Dante interface panels, Solaro XC-SLO and CX-SML audio output cards
Yamaha DXR12and DHR12M monitors, RX-A8A AV receiver,

Control & Video
Avonic PTZ 20x zoom cameras 
Bose VB1 videobars, ControlSpace EX-440C conferencing signal processor
Crestron NVX-360 encoder, NVX- 363 decoder, HD-RX-2000-C receiver, TSW-770 touchpanels, UC-CX100-T Flex integrator kit, RMC4 control processor
LG LED 138-in display, 77EV960H UHD OLED displays
Samsung Flip 3 75-in WMA Series displays, QMR85R 85-in displays

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