San Fransico Ballett Selects Lectrosonics

Dual TM400 systems provide wireless freedom for 9-foot concert grand piano


Kevin Kirby with two UH400TM transmitters installed in the grand piano.San Francisco, CA – March 2008… For the San Francisco Ballet’s 75th Anniversary Gala, the prospect of microphones or microphone stands being visible to the audience was more than one of the venerable company’s choreographers could bear. For Kevin T. Kirby, the San Francisco Ballet’s FOH engineer, whose responsibilities encompass running all audio, video, and communications systems in addition to implementing the technical requests of the company’s Artistic Director and its choreographers, the task of resolving this challenge was dependent upon discrete microphones and wireless transmission capability. He resolved the issue with a combination of products from Earthworks and Lectrosonics.

Kirby was already well aware of the Lectrosonics TM400’s performance attributes, as he had successfully deployed a single TM400 on the same piano using a boundary microphone. “We had been using a boundary mic attached to the underside of the piano’s lid for quite some time,” said Kirby. “While the sound quality was acceptable, the microphone’s plate was clearly visible and, hence, was considered distracting. I was aware that Earthworks manufactured a dedicated piano microphone system, so I decided to look into this as a possible solution.”

With assistance from Michael Moore at Leo's Pro Audio in nearby Oakland, Kirby secured the Earthworks PM40 PianoMic system for evaluation. “Upon receiving the demo system,” Kirby noted, “I proceeded to test the equipment using conventional wired connections. The results were impressive. Not only did the piano sound fantastic, there was absolutely no hint of a microphone being present as the system straddles the piano’s harp just behind the hammers. The microphones are only visible from above.”

“At this point,” continued Kirby, “I realized that by adding a second Lectrosonics TM400, the dual mic Earthworks system could be completely wireless. The Earthworks system sounds better than the single boundary mic we used previously while the Lectrosonics wireless equipment would resolve the aesthetic concerns of the choreographer. Within a very short timeframe, the SF Ballet placed the order for both the Earthworks microphone system as well as the additional Lectrosonics TM400. Our new wireless setup has been operational since mid February.”

The two Lectrosonics UH400TM transmitters are positioned on the upstage side of the piano along with the Earthworks PM40 adapter box, which converts the system’s proprietary 5-pin XLR connector into twin 3-pin XLR connectors for the individual microphones. Short XLR jumpers from the two UH400TM transmitters provide 48 volt DC phantom power to the microphones.

According to Kirby, “I originally purchased the Lectrosonics TM400 for acoustic measurement as part of a SMAART system for optimizing the interaction between sound systems and acoustic spaces. Since the TM400 is designed for precise acoustic measurement, it also functions extremely well as a high-end wireless system, and this is why we began using it on the grand piano. Since there’s no companding, the system’s dynamic range is extremely musical. Of equal importance, the TM400 performs very well in congested RF environments.”

“While we’ve only had the system a short while,” said Kirby, “our experience with the gear has been superb. We’ve received many positive comments on the sound of the PM40 and the way that sound is conveyed by the TM400’s. When people are told the piano is wireless, they’re amazed. This is a true ‘no compromise’ way of maintaining the aural integrity with the visual aesthetics the SF Ballet requires.”

About Lectrosonics Digital Hybrid Wireless™ technology found in the TM400 Wireless System for Test and Measurement
Lectrosonics’ Digital Hybrid Wireless technology uses a proprietary algorithm to encode 24-bit digital audio information with no compression and low distortion into an analog format that can be transmitted in a robust manner over an analog FM wireless link. The result is much higher dynamic range—free from sonic artifacts— than wireless systems using a compandor are able to offer. Digital Hybrid Wireless technology delivers long operating range, graceful signal decay, and a small spectral footprint, facilitating more channels to be operated simultaneously.

About the San Francisco Ballet

As America’s oldest professional ballet company, the San Francisco Ballet enjoys a long and rich tradition of artistic “firsts” since its founding in 1933. The company gave the first American productions of Swan Lake and Nutcracker, as well as the first 20th-century American Coppélia. The San Francisco Ballet is one of the three largest ballet companies in the United States. For additional information, visit the organization online at

About Lectrosonics

Well respected within the film, broadcast, and theater technical communities since 1971, Lectrosonics wireless microphone systems and audio processing products are used daily in mission-critical applications by audio engineers familiar with the company's dedication to quality, customer service, and innovation. Lectrosonics is a US manufacturer based in Rio Rancho, New Mexico.