Tech Focus

Tech Focus: New Bose SoundComm B40 Headset Joins The Arcadia Theater Intercom System

Seats for 1,150, a crew of over 100, nearly a dozen resident companies and a nonstop production schedule – there’s a lot to coordinate at the Arcadia Performing Arts Center in Arcadia, CA.

The venue’s technical director, Keith DeLuca, and production manager, Martyn Tyler, manage whirlwind of scheduling, hiring, equipment, tech support, client relations and beyond. Running the theater has never been an easy job.

“The ability to stay together and be on the same page, at the same time, with the same intention is what drives our shows,” says Tyler. “Without unity, there can be no cohesion, no coordinated timing, and no accurate and efficient production.”

Efforts to improve coordination and communication led Arcadia Theater to adopt the Bose SoundComm B40 headset to a setup already equipped with Bose RoomMatch line arrays.

The SoundComm B40 shares technology with the Official Headset of the NFL – the Bose SoundComm B30. Features from Bose military and aviation headsets were also incorporated into the B40, and the resultant combination of active noise cancellation, active equalization and ergonomic design is Bose’s first offering to the broadcast communication and production market.

Bose produces dual- and single-earcup versions of the B40, both available with binaural 5-pin XLRM or mono 4-pin XLRF connectors. In order to address their need, Arcadia ordered a mix of nearly 20 single- and dual-cup 5-pin XLRM headsets for their Clear-Com intercom system.

“Since we added SoundComm B40 headsets and RoomMatch line arrays into our theater, we have a whole new outlook on Bose’s ability to hit the needs of the pro audio consumer,” DeLuca says.

Active Noise Cancellation

Bose may be best known for its consumer products – active noise cancelling headphones like the QuietComfort 35 are ubiquitous on public transportation across the globe. Professional-grade Bose products apply the same concepts of noise cancellation and clarity, but scale up drivers, add compressors and boost other capabilities to withstand the extreme SPLs professionals face.

“What stood out about the SoundComm B40 was the active noise cancellation. The ability to just flip a switch and turn off the world around me is incredibly powerful,” Tyler says.

Active noise cancellation works by monitoring outside noise, then creating an opposite audio signal to cancel it. The most common visualization associated with noise cancellation depicts one audio waveform heading left, another equal but opposite waveform heading right. When they overlap, the waves cancel one another.

Putting it into practice is more complicated. The B40 uses a proprietary feedback microphone system to collect noise data inside the earcup. It then runs that data through a control loop, then summarizes and compares it to outside noise and the incoming audio transmission. The modified result – clear intercom audio, and very little else – is then produced in the earcup through an optimized driver.

Key Differences In Technology

The frequency range Bose engineers have dubbed “the crossover point” – where active noise cancellation becomes less effective and passive noise cancellation becomes more effective – define, in part, their approach to active noise cancellation.

Passive headsets lock out noise by clamping large earmuffs around users’ heads. It’s an effective approach, especially for blocking higher frequencies – but the downside is a lack of long-term comfort.

Bose active noise cancellation strives to cancel a wider range of noise equally by complementing the high-frequency passive reduction with excellent active noise cancellation for low frequencies, allowing them to produce a headset with less clamping force and greater overall noise reduction.

According to the staff at Arcadia, the Bose approach is effective.
“If you’ve not used a headset with active noise cancellation before, you might think you know what it’s like,” Tyler says. “But you can’t even imagine putting the B40 on and hearing everything just disappear. It’s really, really powerful. It’s really good.”

Active Equalization

Bose has performed significant research to understand what makes communication or audio intelligible – and it’s not the typical full bandwidth that you’d want to listen to the Boston Symphony in.

By lowering the intensity of extreme high- and low-frequency audio, active equalization highlights the range from ~300 to ~6,000 Hz – human voice range – thereby boosting clarity and adding intelligibility.

In developing the B40’s active equalization, Bose engineers carefully considered the production ecosystem. What a user hears is the sum of several different EQs – the unique frequency picked up by the transmitting microphone, the EQ from the intercom and then finally the headset that the user is wearing.

The design of the B40’s active equalization is based on the knowledge of what makes for intelligible audio and the typical intercoms and systems in the market today. Electronic circuitry shapes and equalizes incoming audio signals, bringing transmissions into the range of frequencies most clear and intelligible for the human ear.

“I’ve been thoroughly impressed with the audio quality of the SoundComm B40. It’s the crispest, cleanest audio signal that I’ve ever had from a communications headset,” Tyler says.

Dynamic Microphone

The B40 incorporates a fairly standard directional dynamic mic, with a couple of key differences – the biggest being that it is virtually waterproof, and the second is that it falls in the middle of the typical impedance range, 150 Ohms.

When properly adjusted, the directional mic rejects noise that didn’t come directly from the wearer’s mouth, limiting the amount of unwanted background noise on the intercom system.

“The first time I put on the B40 headset was at NAMM in Anaheim,” recalls DeLuca. “I was on the packed and noisy show floor with a Bose representative, and we could talk back and forth at a very low volume. Someone standing right next to me couldn’t hear what we were talking about. It was incredible to hear the clarity.”

High Standards

DeLuca and Tyler have high standards, and the crew at the Arcadia Theater say the B40 helps them meet the expectations.

“Perfection in production is impossible. But as close as we can get to it, that’s what we strive for,” Tyler says. “But it really is something special when you can look back and say, ‘Maybe that was the one. Maybe that was the closest I’ve ever been.’”

Find out more about the Bose SoundComm B40.