14.03.19

Fraunhofer IDMT shows off high tech test facility

anechoic chamber
Fraunhofer IDMT has one of the largest anechoic chambers in Europe

Anna Mitchell heads to the heart of Germany to explore Fraunhofer IDMT’s Ilmenau facility.

Ilmenau, a seemingly sleepy small German town that is home to just 36,000 people, is punching above its weight when it comes to audio technology development thanks to the Fraunhofer Institute for Digital Media Technologies IDMT.  

Located in the town, the research institute is where the Planar loudspeaker was conceived; and it’s where Wave Field Syntheses (WFS) has been pioneered, from inception through to successful use in a number of global projects. 

When InAVate got a chance to take a look behind the scenes, we jumped it. The tour guide for the day was René Rodigast - business manager of the resarch unit Acoustics at Fraunhofer IDMT’s Professional Audio Group and we began in the 3D presentation room, the institute’s largest experimental room [pictured below]. 
test room
Here, researchers primarily focus on R&D into the Spatial Sound Wave technology. The room is circled by a ring of Kling & Freitag CA106F loudspeakers that were made specifically for Fraunhofer (the F at the end of model number is Fraunhofer). These are supported by Alcons loudspeakers suspended from the ceiling on height adjustable lifts. In total 120 loudspeakers are installed in the room. 

Eight subwoofers are also deployed and there are plans to add two line arrays for testing of conventional sound systems. A DiGiCo S21 mixing desk is on hand and the entire set up is powered by a bank of recently installed Dante-enabled Powersoft Ottocanali amplifiers. 

WFS is object focused, which means audio can appear to come from a specific object (which may be moving), and not the speakers so it was essential that the room had loudspeakers installed in a three-dimensional space. 

The room had to be flexible and able to be configured to the requirements of the team working in it. Rodigast notes that Dante networking technology allows the speaker set up to be switched quickly and easily. 

Room reverberation times can be altered in order to simulate different room types. Ambient sound is captured by mics suspended from the ceiling so that reverberation times can be captured, measured and manipulated. At the touch of a button the room can change from cinema, to opera stage, to home set up for example. 

Behind the scenes is a rack room. “You can see how technology has changed over the years,” says Rodigast as we enter. What he means is immediately evident. On the left is a bank of analogue equipment and it’s huge. Over time it’s been replaced by digital technologies, installed to the right, and you can see how the kit required has slimmed down. PCs equipped with Dante and Madi cards handle control. Every change on the PC, prompts a change in Q-Sys. 

powersoft ampsThere are 16 Powersoft Ottocanali amplifiers [pictured left] in the rack room. Two more are located at the back of the experimental room to power the subs and another two are in the room, available for flexible applications. 

Rodigast opted for Powersoft for the flexibility the units offered and Ottocanali is an upgrade from M Series units. “We needed the flexibility of being able to use Dante or Madi,” he notes. 

The institute invested in 29 Ottocanali 4K4 DSP-D amplifiers in total and use additional units as back ups and in other research rooms around the building. 

Powersoft’s Armonia software was also a draw. “When you are dealing with a lot of channels, you need user friendly, flexible software. Fraunhofer’s Spatial Sound Wave user interface is browser based like Armonia so we can handle both in the same environment,” says Rodigast. 

While not crucial, Rodigast says the power to size ratio of Ottocanali amplifiers was a bonus. 

Opposite the experimental room is one of the largest anechoic chambers in Europe, measuring 10m x 9m x 8m. It’s a sought after facility for researchers from academia, other Fraunhofer institutes and businesses and when you hear what goes into construction of this spaces it’s no surprise. Essentially a building-within-a- building, it’s encased in concrete and takes up three floors. 

Rodigast then sets off through a winding maze of corridors. Behind the doors we pass are researchers’ offices and a myriad of additional test spaces. Three rooms in the facility meet the ITU-BS 1116 standard for listening rooms. Here, reference speakers and codecs can be compared. The institute has opted for Klein und Hummel O500 C and O900 Subwoofer studio monitors. 

The team is working on VR testing at the moment, delivering sound through loudspeakers and headphones so audio better matches the visual content shown. In one application an astronaut crashes on a planet. Through headphones instructions are given, while loudspeakers provide the sounds of the outside environment. 

A VR room contains Seeburg speakers that are active versions of the TS Nano and made for Fraunhofer IDMT. Three LCD displays and VR glasses are used for visual immersive simulation. 

Opening another door, I’m surprised to find a pristine Audi Q7 with a Christie projector mounted on its roof. Fraunhofer IDMT has worked with Audi to equip the car with loudspeakers and developed software to deliver immersive in-car audio. 

Finally we enter the mixing studio where Rodigast takes me through the process of mixing object-based audio tracks. It’s kitted out with Neumann 0 300 loudspeakers and an Avid S3 mixing console. 

The facility is a mecca for audio researchers and engineers. Rodigast estimates that there are more than 300 loudspeakers installed here, there are numerous studios certified to high standards, the recent addition of 29 Powersoft Ottocanali amplifiers has added power and flexibility and then there’s the anechoic chamber. 

But, while it looks like an engineer’s playground, there are no games being played here. Research in Fraunhofer IDMT is influencing and driving forward commercial audio technologies in practical applications the world over. 29 Ottocanali 4K4 DSP-D amplifiers were installed at Fraunhofer IDMT is influencing and driving forward commercial audio technologies in practical applications the world over.