FLEX Back At Top Of The Club Scene With Premium Sound

Sound demo at FLEX, 4x BC543 + 8x QR24 + 2x QM24 at main stage – photo credit Alisa Larchenko

The club FLEX is an institution of Vienna’s nightlife. Uniquely located in a closed metro tunnel, FLEX has been delivering danceable beats and live concerts by newcomers and international acts of various styles since 1990. FLEX is not only one of the most famous clubs in Europe, but also known for the finest sound in the Austrian capital. The latter does not come by chance, but from Alcons.

The sound system evolved with the club, and over the years various installations have been made – since 2007 all planned and installed by Pro Performance, Alcons distributor in Austria.

Minimum space and maximum power

Initially, in 2007, 6x Alcons QR36 (6x 6.5”) modular pro-ribbon line source array column loudspeakers were installed on the main floor and two additional QR36s were installed in the café, which is located in a porch adjacent to the club entrance. Three Sentinel 10 Amplified Loudspeaker Controllers were available at this time to drive the Alcons systems. In addition, the main floor horn subwoofer system received an update at this time, with five bass speakers being added to the café’s sound system. In 2007, the requirements were obvious: minimum space requirements and maximum power. Alcons’ pro-ribbon technology led the market then, as it does now, when it comes to finest sound quality paired with maximum power.

Finally, FLEX was due for its next evolutionary step, which involved a comprehensive update of all sound systems. The eight QR36 loudspeakers, of which not a single one had failed in 15 years of operation, have since been moved to the club’s large outdoor area – a true Viennese summer hotspot – where they are being powered and controlled by an Alcons ALC amplified loudspeaker controller.

Main floor equipped with Alcons pro-ribbon QR and QM systems

Since 2022, sound reinforcement duties on the main floor are being shared by 8x Alcons QR24 full-range modular pro-ribbon line source loudspeakers (4x QR 24/80 and 4x QR 24/110) with 2x Alcons QM24 modular line source LMF array extensions. These modular elements form two left and right arrays of 3,3m/10.8-ft. tall each.

Four BC543 (triple 18”) cardioid bass systems are placed on the stage, 2 stacked on both sides, with wideband FRPA absorbers from another manufacturer. The specially constructed horn subwoofer system is a concrete bass system with 4 15″ chassis on either side, which gives a deep, belly-felt low-end feeling. The BC543s are cardioid subs keeping the bass off the stage (rearward) and work together with the horn (forward) to produce the powerful bass feeling that FLEX has always been known for.

photo credit Alisa Larchenko

The QR24 is a modular 2-way column loudspeaker to be used as vertical array system, with 4x 6.5” neodymium LF and 2x 12“ pro-ribbon driver HF. It combines a perfectly natural, dynamic sound reproduction with superb intelligibility and throw, in even the acoustically most challenging environments. The QM24 “array fill” module is a modular, limited bandwidth column loudspeaker which provides extended frequency control and increased LMF throw as an extension to QR arrays.

“The customer needed an extremely flexible solution, as FLEX hosts both live events and concerts as well as club nights. The main floor has a great geometry and offers a magnificent sound in combination with the horn subwoofer system. The great length of the room is perfect for Alcons’ innovative QR24 system. As in any club, at FLEX it’s about consuming as little space as possible with any kind of installation, of course,” says Wolfgang Sauter from Pro Performance.

“The system at FLEX has convinced both me and the numerous technicians of the international bands to hundred percent and also receives a lot of praise from the audience after the concerts. In this respect, I am happy to be able to mix on the system every day anew, says Andi Bogner, sound engineer at FLEX

On the main floor, the generous QR24 and QM24 update now offers significantly more headroom as well as better processing. The line source speakers also blend well into the design of the room and combine perfectly with the horn subwoofer system, which has also been upgraded with new high-performance speakers.

FLEX Café’s sound system optimization

In the popular FLEX Café however, completely different requirements had to be met. The room previously had sound emission problems. For this reason, the Pro Performance team chose an end-fire configuration for the bass speakers to maximize bass cancellation at the rear. At the same time, bass traps were installed (at 20, 25 and 35 Hz) to guarantee the desired volume in the café. This in turn required additional power in the form of an Alcons LR18 double 8” pro-ribbon line array system. In addition to the bass systems, the café’s sound system now consists of 2x 3 Alcons LR18/90 left and right from the stage, 2x Alcons ALC4 and a Sentinel 10 Amplified Loudspeaker Controller.

LR18 in FLEX Café – photo credit Alisa Larchenko

“The FLEX Cafe has a low ceiling. We chose the LR18s here because they provide exceptional sound that is evenly distributed across the horizontal plane,” adds Wolfgang. “They combine very well with the bass systems to provide a clear, punchy sound. In total, seven bass traps are used in the café, which significantly improves bass absorption and allows the music to be cranked up even more.”

Andi Bogner, sound engineer at FLEX, says about the sound system: “The system at FLEX has convinced both me and the numerous technicians of the international bands to hundred percent and also receives a lot of praise from the audience after the concerts. In this respect, I am happy to be able to mix on the system every day anew.”

Wolfgang Sauter – photo credit – Jessica Roes

“Alcons is the sound of Vienna, at least at nightclub level,” Wolfgang notes. “FLEX was the first club in the world to use Alcons loudspeakers. The reliability and overall manufacturing quality were a major reason for the customer to choose Alcons. In recent years, we at Pro Performance have installed Alcons Audio solutions in a whole range of venues in both Vienna and across Europe, with the installation at FLEX being something very special. Back in 2007, a loudspeaker shootout was held at the club, which Alcons won not only because of the excellent sound quality, but also because there were no other vertical column loudspeakers available on the market at the time. And in 2022, Alcons is still ahead with its QR24 series.“

He concludes by saying: “FLEX is very satisfied. The café had always been the venue with acoustical sound issues. Now it has transformed into a floor that can easily compete with the finest Vienna has to offer. Together with the incredible main floor, FLEX is undoubtedly reporting back to the top of the European club scene.”

For more info: www.properformance.at und www.flex.at

Alcons products involved:

• QR24/80
• QR24/110
• QR36
• QM24
• BC543
• LR18
• Sentinel10
• ALC4

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