Bowers & Wilkins’ Noise-Canceling Headphones

Walk into any electronics store and you will see an entire aisle devoted to noise-canceling headphones. A multi-billion-dollar business, headphones continue to grow at a rapid pace in the marketplace. So, what does an established audio brand need to do to stand out and gain market share in this lucrative and highly competitive space?

Bowers & Wilkins, a high-end audio manufacturer, famous for their signature line of speaker systems, believes it has the answer – deliver excellence in sound engineering, high performance, and low power consumption. With the help of their longtime technology partner, Analog Devices (ADI), Bowers & Wilkins overcame daunting technical challenges, bringing their signature sound to a wider audience. Working collaboratively, ADI and Bowers & Wilkins brought a new line of adaptive noise-canceling wireless headphones to market – the PX5, PX7, and P14 – giving listeners music in all its glory.


At a Glance

Company/Industry:

Bowers & Wilkins is a leading global manufacturer of high-performance audio technology for more than 50 years

Applications:

Precision home speaker systems, headphones, custom installations, and performance car audio products

Challenge:

Employ low power consumption while extending battery life, reducing latency and maintaining high-performance

Goal:

Achieve industry-leading noise cancellation without compromising Bowers & Wilkins’ signature sound. Provide an unsurpassable, personal music listening experience.


The Trajectory of a New Market

Bowers & Wilkins had its ear on the drumbeat of changes in the marketplace – headphones equipped with analog audio jacks were a dying breed. Feeding this worldwide trend were efficient, rechargeable battery power sources and “active” technology that enabled headphones to perform numerous functions, including noise cancellation.

It was this last point of noise cancellation and changes in the behaviors of the market that piqued Bowers & Wilkins’ interest. Previously utilized mostly by heavy airline travelers, younger users were using headphones more and more to isolate themselves from their surroundings and those near them – on a train, in an office, and even at home – creating their own personal, immersed space. Bowers & Wilkins reasoned that the trend would only increase as our cities grew larger, people experienced longer commutes, and the quality and quantity of digital information and entertainment increased.

“Keep out the world so you can live fully in yours.”

Bowers & Wilkins


The Opportunity and the Challenge

Bowers & Wilkins recognized an opportunity to extend its brand to the “isolation” market. But several challenges needed to be addressed first. Consumers demanded high performance and long battery life for extended listening time, while Bowers & Wilkins was focused on developing noise-cancelling algorithms while retaining the quality of its signature sound to exacting standards. Incorporating these requirements would not be easy.

While Bowers & Wilkins are leading experts in acoustic sound design and signal processing, they needed a partner with expertise in the technical integration and implementation of systems solutions to develop the high-performance signature sound, noise cancellation headphones they envisioned. They turned to longtime partner, ADI.


True Collaborators

A history of working collaboratively enabled ADI and Bowers & Wilkins team members to share an affinity and like-mindedness. “Bowers & Wilkins had a good understanding of our capabilities. They knew precisely what they wanted to achieve with their software and presented us with requirements that needed to be translated back to the spec,” said Rajeev Morajkar, Product Applications Engineer Manager, Healthcare and Consumer Systems, ADI. “We understood what they wanted to do and developed an integrated solution to achieve their goals.”


Creating a Digital Hybrid

Analog noise cancellation has existed for years, but ADI was one of the first to pioneer a digital hybrid. Hybrid, in this case, meaning feedforward and feedback – having tiny microphones monitor sound outside the headphone and another to monitor the sound inside the headphone. Bowers & Wilkins integrated the technology into their noise-canceling headphones.


active noise cancellation
The ANC (active noise cancellation) chip is simultaneously listening through built-in microphones to the noise created by an external source AND the sound that is created by the headphone speaker playing into the ears.


algorithm
Employing feedback and feedforward, Bowers & Wilkins developed custom algorithms, built-in microphones and included an ANC chip that actively “listens” for unwanted external noise (A), then plays sound that is 180 degrees out of phase (B), so the noise is “removed” (C) by the time it reaches your ear. To accomplish this task, digital processing must be fast.


Efficient Noise-Cancellation and Low Power

Josh DeStefano, Public Relations Manager, Corporate Marketing & Customer Experience at Analog Devices said, “ADI’s power supply solution offers the lowest power consumption by far for this type of technology. And, the overall playback path offers the lowest power implementation. The combination enabled Bowers & Wilkins to develop a brand new noise-cancelling headphone platform with multiple levels of ANC, some of the longest playtime available, and all while further improving the Bowers & Wilkins sound all music and movie lovers can appreciate.

“Our PX5 adaptive noise-canceling headphones offer 25 hours of playtime on one battery charge. And the PX7 headphones offer 30 hours of playtime,” said Ron Vitale, Sr. Director, Headphone Product and Portfolio Management, Bower & Wilkins. “What stands out here is our practical ability to hit these performance levels at extremely low power. It’s our mixed-signal and domain knowledge that lets us be so efficient,” said Josh DeStefano.

Rajeev Morajkar, ADI said, “The underlying digital technology opens the door to the sheer number of features and capabilities this type of noise-canceling and noise filtering can achieve. Not just the quintessential noise-canceling “‘drowning stuff out’” other competitors can produce, but the ability to customize sound extensively.” For example, the system can “listen in” and try to figure out if you in a meeting room, in an airplane, or walking around a mall and adjust the parameters. As both a listener or manufacturer, it allows you to adjust how aggressively it does that and let voices through.


The Advanced ADAU1787 Chip

ADI’s new ADAU1787 chip was tapped as the core technology to build Bowers & Wilkins’ headphones. “When the ADAU1787 chip was first being designed, Bowers & Wilkins was given the opportunity to take a hard look and offer ADI feedback,” said Matt Windmill, Key Account Manager, European Sales, Analog Devices. “We incorporated several of their suggestions, which improved the design.” Bowers & Wilkins not only gained valuable insight into the design of the hardware as a result of the iterative development and review process but an understanding of the choices that were made, and how they could exploit the chip’s capabilities to deliver their custom software and signature sound.


ADAU1787 simplified block diagram
ADAU1787 simplified block diagram.


The ADAU1787 technology enables ADI customers to create cool, new features – allowing in certain sounds, canceling out other sounds, or automatically adjusting to certain parameters and reacting to the environment. The low-power codec with a programmable Fast DSP (digital signal processor) engine enabled advanced features and provides reliable digital signal processing solutions suitable for many audio and speech applications including speech enhancement, noise reduction, echo cancellation, level control, acoustic feedback cancellation, microphone arrays, and active noise and vibration control.

“Bowers & Wilkins had an outsized impact in the original design of the ADI ADAU1787 chip and in the specs that we targeted. They were able to get better access to the innards of the chip and put out a better product because we had given them access to the details of the technology.”

Rajeev Morajkar, Analog Devices


Enabling Bowers & Wilkins’ Signature Sound

Low power consumption, long battery life, low latency, high performance—when all was said and done, none of it would have mattered at all if Bowers & Wilkins couldn’t deliver their signature sound faithfully to the listener. To that end, ADI integrated its Sigma Studio configurable software into the systems solution, enabling Bowers & Wilkins to develop their custom software and shape the sound delivered to the listener’s ear to exacting standards. A graphical programming tool, Sigma Studio allows one to drag blocks to produce code. Josh DeStefano, ADI, said, "The advantage is you don't need an assembly language programmer to work with the software. If you are knowledgeable in acoustics but not coding, you can easily do what you want.”

Sigma Studio can be used to tunes speakers, process voice, and enable more signal processing. With eight digital microphone inputs and two analog differential audio outputs, it can do more than competitive brands and was perfect for Bowers & Wilkins’ signature sound requirements.


SigmaStudio® graphical development tool.
SigmaStudio® graphical development tool.


Bowers & Wilkins Delivers Music in All Its Glory to the Market

In September of 2019, Bowers & Wilkins achieved its goal of launching an acclaimed industry-leading noise-cancellation headphone series without compromising its famous signature sound. The PX5 and PX7 were released into the market to outstanding reviews from the audio industry.

“Bowers & Wilkins possessed expert acoustic knowledge we could leverage, and we had the deep domain knowledge, and systems integration and technical know-how to make what they wanted to do, practical,” said Matt Windmill. Collaborating and combining expertise enabled ADI to quickly develop the high performance and specific audio functionality Bowers & Wilkins needed to stand out in the marketplace. As a result, ADI amplified its domain knowledge in acoustics while raising Bowers & Wilkins’ understanding of what can be accomplished using ADI’s chips, system solutions, and technology.

Ron Vitale, Sr. Director, Headphone Product and Portfolio Management, Bower & Wilkins, said, “We’ve both worked extremely hard to create a line of headphones that absolutely represents Bowers & Wilkins’ exacting audio quality and attention to detail, while also providing the latest in noise-cancellation and battery saving technology – for an experience every headphone user can absolutely appreciate.”


PX7 over-ear noise-cancelling headphones.
PX7 over-ear noise-cancelling headphones.


“Pressing the button on the headphones’ left cup allows you to cycle through modes ('low,' 'medium,' and 'high'). ‘Low’ is fine for keeping office chatter and background noise out, while ‘high’ effectively cocoons you in silence, even during the noisiest real-life scenarios.”

WhatHiFi.com


About Bowers & Wilkins

Bowers & Wilkins, famous for its signature sound, has been at the forefront of high-performance audio equipment for more than 50 years. Founded in Worthing, West Sussex, England, in 1966, the company has researched, designed, and manufactured high-quality speakers and headphones, setting the standard for innovation and sound quality and earning numerous awards and endorsements from the world's leading recording studios, musicians, and audiophiles. In 2018, Abbey Road Studios, a global music icon, named Bowers & Wilkins “Official Speaker and Headphone partner” and the preferred speaker of their award-winning engineers.