When Matthias (Teese) Gohl was asked to create the perfect sound for a five-week run of the powerful show “Antigone in Ferguson” at the Harlem Stage in New York (Sept 13 – October 13, 2018), he contacted Frank Filipetti (a longtime friend and colleague, as well as a multiple GRAMMY® Award-winning producer, engineer and mixer) to consult on the project. The challenge was to capture clean sound from multiple microphones in close proximity in a very high SPL environment using wireless beltpacks (which allowed performers to move freely) without compromising the powerful and passionate vocal performances.

Additionally, the Harlem Stage theater is surrounded by mobile cell towers, and operating “traditional” wireless microphones, even in the 500MHz band, in this environment is difficult and unreliable.
Filipetti, who was involved in developing and testing a new microphone technique he thought would work well with a high-powered choir, recommended Gohl call upon Alteros, an Audio-Technica company, to provide both microphone and wireless solutions. Using the Alteros GTX 6.5 GHz Ultra Wide Band digital wireless microphone system, the Alteros team connected custom prototype microphones to Alteros GTX24BP transmitters, turned them on, and that was simply “it.” The novel microphone technique combined with the solid reliability of the GTX series wireless, plus GTX’s outstanding, real-time, companderless digital audio, was a match that provided unparalleled quality. Filipetti exclaimed, “This is the wireless mic system for people who hate wireless audio!”

The show utilized 18 GTX24 wireless beltpacks, and the system was set up and fully operational in only two hours. 11 GTX32 transceivers were positioned to create a coverage mesh for the stage/performance spaces plus the green room and backstage hallway. Guest actors wore GTX24 beltpacks with traditional “speech” microphones. Choir members and soloists wore custom microphones utilizing what Alteros President and CTO Jackie Green affectionately calls the “Filipetti PPO,” a “perceptually performance-optimized” approach. Instead of utilizing the typical small theater microphones, which would never stand up to the high-intensity voices of the soloists in this performance, Alteros employed Audio-Technica U853R microphones with hypercardioid capsules positioned on a custom over-the ear mount. The capsules are placed directly in the line from the performer’s mouth to ear against the face. This allows for pickup of only the individual performer’s voice, rejecting even the sound of the neighboring performers as they stand in the choir and rejecting the sound from the monitor wedges and from house sound reinforcement as the soloists venture into the audience with their intensely moving performances.

Why the “PPO” label? The U853R capsule is interestingly close to the same diameter as the human ear, and the microphone length is also roughly similar to the ear canal. The microphone is placed in the exact path of the performer’s own voice to ear – perfectly placing the microphone to capture sound that has been optimized by the performer in an adaptive response to their own perception of sound quality.
The GTX24BP transmitters are the perfect match for this new high-quality microphone option. Operating in a fully native digital format, the GTX24 immediately converts the microphone signal to digital and then transmits in 500MHz wide pulses. A patented sync algorithm pulls every transmitter back into full audio sync every digital frame. This allows for the audio – even the over-the-air signal – to remain in perfect sync. Latency for the entire system is under 3mS, and there is no compander. The result is a high-bandwidth, high-dynamic-range, low-latency, full-frequency response signal that is superior to other wireless methods. Performers singing on this system often make statements such as “This is the first time I feel comfortable singing on wireless,” or “This is the first time I sound like me.”

“The Alteros system was remarkable – the most natural sound I’ve ever heard on a wireless system,” stated Filipetti. “What I noticed was I never once heard any crackling, popping, or snaps coming from the microphones. In a super-challenging environment, we got the best, most emotional choir vocal sound I have ever experienced. Because of where the mic was placed on the performers, we got absolutely no breathing noises, no overloads on the microphones, none of the sputtering that happens when you have one of those small mics in front of the vocalist’s mouth opening which can overload the mics, and you get low frequency distortion that compromises the sound. Because of that you usually end up needing a hi-pass filter well into the vocal range.” Such microphone artifacts, he continues, “combined with the compression and expansion of the traditional wireless system, just makes them highly undesirable and very difficult to mix. Using the Alteros system, without doing any equalization or compression, as the singers got louder and louder it didn’t get brittle, it literally just got louder.”

Alteros’ Green believes that many theater and opera performances would benefit from this new microphone method. “Some performances are fine with hidden ‘baby mics’ – but you don’t put singers like this into miniature microphones on beltpacks with companders and compromised audio performance. No more baby mics! And, no more RF interference and coordination problems. Alteros is honored to be part of this outstanding show and part of this real-world proof of Frank Filipetti’s concept.”