Thalia Theater Hamburg Enhances Sound System

Hamburg’s Thalia Theater had already chosen an Alcons QR36 pro ribbon line-source column loudspeaker system to solve its sound reinforcement challenges in 2007. At that time, it was still designed for mainly spoken word performances. In the meantime, however, the theatre evolved into a very musical stage. Accompanying this transformation was the growing desire of the sound engineering department, headed by Rewert Lindeburg, for more precise bass reproduction and more headroom, which was initially met in 2021 with a first bass extension. Subsequently, a new sub-bass system was installed following the plans of Stefan Flad, sound engineer at the Thalia Theater. Once again, Alcons Audio proved to be the first choice.

Complicated starting points
Already during the first Alcons installation in 2007, the special acoustic challenges of the theatre became apparent. The very high auditorium has very little floor space, and the geometry of the room makes uniform sound reinforcement pretty difficult. In addition, there are the usual problems of getting sound under the galleries. The first installation of Alcons QR18 pro ribbon column loudspeakers (3x 6.5”), QR36 pro ribbon line source column loudspeakers (6x 6.5”) and small format LR7 pro ribbon line array systems (1x 6.5”) provided initial relief to that situation.

“At the time, we were looking for something compact and extremely precise that would only cover the audience and nothing else,” recalls Ben Schröder, sound engineer at Thalia Theater. “That works perfectly with the installed Alcons systems up to this day. Since then, we have been able to project significantly more direct sound into the last rows without long arrays or too many reflections. What we lacked over the years, however, was headroom in the low mids and high lows. We wanted to be able to perceive the low ends as a direct impulse. And this is where the trouble began…”

“With the addition of BF121s for the high bass and the new amps, we were able to turn a speech PA with deep bass into an inherently more balanced-sounding musical PA with enough headroom from the lowest ends all the way up to the high-resolution highs, without having to design a whole new PA system”. Ben Schröder, sound engineer Thalia Theater.

Meeting light and sound demands
“So initially in 2021, we tried to expand the front basses by adding a small BF121 mkII (1x 12”) sub to each top, while at the same time revamping the upper tier sound reinforcement. This worked quite well from a sonic perspective and also provided the desired increase in headroom for live music. But there was another problem: We were always in conflict with the lighting, specifically the follow spots, because the PA was just hanging too low.”

Therefore, four LR7 pro ribbon line array systems were added, allowing to split the center array and provide more flexibility in collaboration with the lighting.

New sub-bass system
To achieve better low-frequency imaging, a new sub-bass system was installed next. It consists of 4x Alcons 1x 15” BF151 mkII subwoofers (installed as a 2×2 cardioid pair above the gantry, two more under the upper tier sound truss and another two units above the upper tier sound truss, with all eight woofers calibrated in two positions as one mono system. After 15 years in operation, the existing amplifiers also had to be replaced, so four analog ALC2 and ALC4 amplified loudspeaker controllers were exchanged for 6x Sentinel10 amplified loudspeaker controllers from Alcons Audio.

Stefan Flad explains, “We chose Alcons’ small 15” woofers because we didn’t have a lot of space available and could only add limited weight to the roof. It was a long evaluation process, but in the end it became clear that there were hardly any other alternatives to achieve the desired low frequency imaging and more headroom in our particular situation.”

Endfire bass center cluster
The new bass cluster is installed in endfire configuration. This allows for a variable configuration of eight 15” BF151 mkII woofers, each of which can take on different tasks as a pair. This approach still required a lot of sensitivity with regard to the lighting. So an additional loudspeaker was added to the center cluster, to be used only in those situations when the lighting would hang so low that it obstructs parts of the center cluster.

“Especially with the lighting in mind, we came up with the idea of building a cluster made of small woofers. The BF151 mkII are doing a fantastic job here! Such a deep, rich bass response with lots of dynamics from such a compact 15” system – that totally blew us away,” Ben Schröder laughs. “After all, a 15” is never enough for a subwoofer system, right? Except with Alcons. Even the 12” BF121 is a sufficient woofer and incredibly loud with no audible distortion. With the whole system up and running, you can actually hear the difference quite clearly when you turn that BF121 on. That’s remarkable.”

He says that the new central upper bass led to an ability to turn down the other woofers by 5dB while maintaining the same volume in the stalls. “Now we not only have more bass from the ceiling, but the overall distribution in the house is fantastic, and we’re really having fun at the mixing desk. The musicians are also thrilled,” adds Stefan Flad.

“Alcons knows what deep bass is”
When asked why Alcons Audio was still the first choice for the Thalia Theater, Ben Schröder replies, “If you like ribbon tweeters, Alcons is certainly the top choice. For us, this technology has advantages because we need a lot of low end. And the Alcons woofers are simply outstanding. Alcons really knows what deep bass is. The small, deep-sounding BF151s and the sophisticated woofer system designed by Stefan Flad and Heiko von Wallis made this extraordinary sound reinforcement concept possible in the first place.

The result is a truly remarkable sound reproduction. “In January / February 2023, we hosted the Lessingtage [Lessing Days] with a wide range of performances. The visiting artists were consistently enthusiastic and kept asking us about our great sound system. That really feels good after the very delicate system planning phase,” adds Ben Schröder.

Industrial Arts GmbH from Glinde, Germany, installed the system. Heiko von Wallis (echo image) was in charge of calibrating the system and gave precious inputs throughout the whole planning phase, which also required some custom solutions.

“It was only thanks to the dedicated efforts of everyone involved that a very convincing solution could be achieved and the requirements of the lighting department could be balanced with a modern bass reproduction for the audience,” concludes Stefan Flad.

Alcons system setup at Thalia Theater
Stalls:
1x Alcons QR36 and 1x Alcons BF121 per side (used as one loudspeaker).
2x BF 362 (sub bass for the whole theater in combination with the BF151 array).

Box tier:
1x Alcons QR18 and 1x BF121 per side, (used as one speaker)

Middle tier:
1x Alcons QR36 per side

Upper tier:
4x Alcons LR7 and 1x BF121 per side, (used as one system).

Center 1:
8x Alcons LR7 for stalls, box tier, center tier.

Center 2:
3x Alcons LR7 for upper tier and
1x LR7 (If upper part of center 2 is blocked by spotlights, this speaker is used as center for the middle tier. In this case, the entire upper tier sound system is moved mecha-nically).

Sub array:
4x Alcons BF151 (two cardioid pairs above the gantry)
2x BF151 under the upper tier sound reinforcement truss
2x BF151 above the upper tier sound reinforcement truss (all calibrated as one system).

Amplification and drive
6x Sentinel10 amplified loudspeaker controllers newly installed
1x ALC6 (inventory)

More information on www.thalia-theater.de

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