Huge Modern Penthouse Is Acoustical Nightmare; Are Line Source Speakers the Solution?

Case Study: The Golf Loft penthouse in Brussels is a huge, open space with 108 feet of floor-to-ceiling glass walls, which presented acoustical challenges until the integrator turned to line source speakers for the audio.


The Golf Loft penthouse in Brussels, Belgium is aptly named for the private golf course that sits on the rooftop terrace. Housed in the building of a former tribunal court, the almost 10,000-square-foot space had been remastered as a large, open living space offering impressive views of downtown Brussels. The owner, a real estate developer, envisioned a high-end space that was not only high-tech but also the perfect backdrop for hosting and entertaining clients. There was just one problem for the integrator — choosing loudspeakers for such a wide, open, acoustically-challenged space.

Part of the modern appeal of the room is the roughly 108 feet of floor-to-ceiling glass walls and roughly 3,229 square feet of marble flooring. While these surfaces offer an impressive view and complement the historical architecture outside, they were an audio hurdle for Jan Martens, integrator on the project and founder of Belgian installation company Woelf.

The client wanted a distinct audio zone for the bar and dining area. He envisioned his guests mingling at the space’s bar, dining table or pool table while enjoying music. 

The challenge for Woelf was finding a speaker solution that would deliver incredible audio without reflecting off these surfaces and overwhelming the room — and the guests — and degrading the audio experience.

Point Source Speakers vs. Line Source Speakers

A traditional point source speaker wasn’t a feasible solution because the technology pushes sound out in all directions, encountering and reflecting off the ceilings, floors and walls.

Listeners would hear more sound bouncing of the room that sound directly coming from the speakers, which would result in poor clarity and intelligibility. The louder you play the more reflection you bring which quickly becomes unpleasant. The further away from the speaker the harder it would be for guests to hear any direct sound at all.

Instead, Jan selected line source speakers from Wisdom Audio, specifying two Wisdom Audio line source freestanding loudspeakers. Featuring a slim, elegant design, the speaker met the client’s aesthetic requirements.

Because the speaker uses line source technology, Martens solved many of the acoustical challenges of the highly reverberant space. The line source technology provides more direct sound versus reflected sound.

It propagates sound in a line versus a sphere like a traditional point source speaker, eliminating floor and ceiling reflections that can distort the audio. Sound is pushed directly where it needs to go — the listener’s ears.

High ceilings and glass windows posed an acoustical challenge for integration firm Woelf. See more photos.

This kind of speaker is ideal for large rooms and open spaces, or those with architectural challenges including cathedral or coffered ceilings, hard floors, high ceiling and glass walls.

The result is high resolution, low distortion and great dynamic range at any volume level. 

Throughout the bar area, the volume stays almost uniform throughout the space, preventing guests who are closer to the speaker from being blasted at high levels and allowing those farther away to hear and enjoy music at almost the same level.

“Although the space is breathtaking, it was visually and quality wise very difficult to integrate. With the line source, the result is beautiful and everyone have can the same listening experience and carry on conversations anywhere in the room,” says Martens. “My client was astonished because he thought he’d have to sacrifice the audio quality and have the room be really noisy. It was a great experience making the connection between high-end audio and design.”

Check out the photos here.