How Sonos built a more open-minded, smart speaker during the Big Tech era.

When Sonos decided to build a voice-controlled speaker, it was a strategic shift as much as it was a new product. Not only did our team face the challenge of creating a voice-enabled speaker for a multi-room sound system, something no one had done previously, we were now also going head to head with some of the biggest technology companies in the world. Thankfully, Sonos has been focused on reinventing home audio for over 15 years.

Brendan Welch, Product Creation Leader
Brendan Welch, Product Creation Leader

That track record of innovation and experience leadership would lend itself well to the task at hand; building a new way of listening. There are plenty of so-called smart speakers out there, however, the first insight in our product development was that these remarkable devices were not actually built for listening. They use voice-control and AI mostly to speed up productivity, make shopping easier, and add depths to engagements with certain Big Tech platforms. (And yes you could also listen to music on them.) We were determined to make a smarter speaker, one that would have the joy of listening as its primary objective.

The first and probably most difficult principle that we had to adhere to in order to achieve this objective was openness. Sonos has always been open to different music services, in order to live up to our experience standard in this new product, we realised we would also need to be open to multiple voice assistants so that people could craft their own sonic experience.

We also noticed that many smart speakers are designed in a way that diverts your attention from the music to the tech instead. The speaker obviously had to look good but we always focus first and foremost on making sure our speakers fit naturally into people’s homes. That means they don’t need to be in the centre of the room to sound great and they don’t need to grab your attention with a bunch of lights and alerts.

To make this ambitious vision a reality, a relatively small team grouped together and dreamed up what would become Sonos One and the groundbreaking software experience behind it. Its creation, retold here by several insiders, represents a leap forward not just for Sonos as a home sound system, but as a platform upon which new and exciting things can be built.

Built from the ground up (well, almost).

First, a voice-enabled speaker requires a voice assistant. We knew that Amazon had a lot of expertise in this area. The Echo experience was inspiring and Alexa had grown into a remarkably capable voice-control platform, with the support of some of the most sophisticated machine learning technology in the world. And rather than keeping Alexa in a closed box all to themselves, Amazon had turned it into an open platform that others can easily work with. So it was only natural for Alexa to be our first voice control partner.

Before we could build any parts for a voice-enabled speaker, we needed to determine just what it would look like. “We ultimately decided to build on the backbone of the Play:1,” Product Manager Allan Velzy explains, “From an experience perspective, the Play:1 was our most popular speaker at the time not only because it sounds amazing but also because it can go in any room.”

Allan Velzy, Product Manager
Allan Velzy, Product Manager

Despite looking nearly identical, Sonos One and Play:1 only share two of the same parts: the feet and base. “Because we were adding microphones and lights, everything had to be redesigned,” says Velzy. These additional elements are a major part of a design where every millimetre counts, tweeters and woofers are tailored to the unique architecture of the speaker.

The team studied the Echo and thought about how to refine the Sonos One experience. “One of the more interesting challenges was we knew we wanted to offer the opportunity to turn the mics off,” he explains. They noted that when you turned the mic off on the Echo, the speaker would light up red. “It felt kind of scary and negative. We didn’t want that, so we just paired a microphone icon – no line through it – with a small LED light. If the light is off, the mic is off. We also hardwired the microphone array with the LED, so there’s no way for the microphones to be on without that LED on. It’s a little privacy feature but great for security.”

We wanted to make Sonos One visually quiet but sonically awesome.

They also reviewed the Echo’s highly visual interface. For example, when you say “Alexa” it lights up blue. Sonos took a different approach. “We wanted to make Sonos One visually quiet but sonically awesome, so we went with an audible interface,” Velzy continues. “When you say ‘Alexa’, it makes a little chime, signalling it can hear you.”

A speaker that listens as great as it sounds.

Teaching Sonos One to hear voice commands proved to be a challenge. After all, before this project the team only had to worry about the sound coming out of speakers, not what was going into them.

Brendan Welch, who helped prepare Sonos One for production, played a key part on the hardware side, helping to build the microphones into the speaker. “First, we had to get the electrical design right so there’d be no interference with voice signals,” he explains. “Then we had to select a microphone that’s sensitive enough to pick up a voice but robust enough to handle the very high sound pressure levels output from the speaker.” Finally, the microphones had to be properly sealed with a transparent acoustic barrier to maintain consistent performance and withstand external contaminants.

Klaus Hartung, Director of Smart Audio and Voice
Klaus Hartung, Director of Smart Audio and Voice

Klaus Hartung, Director of Smart Audio and Voice, worked with his team on software that could distinguish a voice command from music, conversations and all the other sounds in a room. “People think we can just subtract the music from the microphone signal. It is much more complicated,” says Hartung.

If we wanted to let people place the speaker wherever they wanted in a room, we had to apply echo cancellation. “Every room and every placement is unique,” explains Hartung. “Depending on the size of the room, the placement of the speaker, the materials in the room and even where people are, the sound waves change.”

Before Sonos One can “subtract” the music, it must account for those changes using an algorithm, which creates a filter that simulates the acoustics of the room. Using what’s called a beamformer, the Sonos One is able to suppress unwanted sounds, such as noise from appliances. Another algorithm ensures that the speaker only reacts when it hears the famous wake word, “Alexa.”

A smart speaker that’s actually smart.

Developing voice control for a whole home sound system was something no one had ever done before. So, it tested both the Sonos and Amazon Alexa teams to make sure Sonos One would be able to do whatever command follows “Alexa”.

Mieko Kusano, Senior Director of Product
Mieko Kusano, Senior Director of Product

“With the Echo, you can say ‘Alexa, play The Beatles’ and the device will start playing. We wanted the same short and sweet experience,” explains Mieko Kusano, Senior Director of Product Management. The added complication of multiple rooms, however, demanded a deeper integration with Sonos than Alexa had with any other partner. “Otherwise a command would have looked something like, ‘Alexa, tell Sonos to play the Beatles on Spotify in the bedroom’. I think we can all agree that’s not very natural,” Kusano laughs.

Together, the teams worked to cut out all the unnatural, excessive phrases. “Instead of ‘tell Sonos’, you simply link Alexa to Sonos during the setup. Instead of ‘on Spotify’, you can set your preferred music service in the Alexa app. And while you can specify ‘in the bedroom’, you don’t have to. The speaker will assume you are speaking directly to it and any other speakers grouped with it,” explains Kusano.

 

We want the listener to enjoy their home life without tech feeling like a burden.

 

Dayn Wilberding, Creative Director of Experience
Dayn Wilberding, Creative Director of Experience

Another part of making the user experience easy and intuitive was implementing continuity of control. That means, however, that the listener chooses to control Sonos through our app, via partner apps like Spotify, the buttons on the speaker, or by using their voice, it should work flawlessly, even when people jump from one control mechanism to another.
“We want the listener to enjoy their home life without tech feeling like a burden,” says Dayn Wilberding, Creative Director of Experience at Sonos. “People shouldn’t have to think about how music started or determine the ‘right’ interface for a task. Everything should just stay in sync.”

Even better things to come.

Lidiane Jones, Senior Director of Software Product Management
Lidiane Jones, Senior Director of Software Product Management

Sonos One was designed not only to work every time, but also to get better with time. This is why we built our own platform to manage the voice experience, making sure it could keep up with the rapid pace of technological development. Of course, Alexa will get even smarter over time, but so will the entire Sonos platform, as new AI-powered voice assistants are added.

Voice lets the technology fade away…

“Voice control is still in its infancy,” explains Lidiane Jones, Senior Director of Software Product Management. “We built Sonos One with the flexibility to innovate and evolve.” Over time, with updates, customers will get support for Google, voice control for an expanded set of music services and additional features in the Sonos app. We knew we wanted to support multiple voice services the same way we support multiple music services.”

Chris Kuruc, a Principal Product Manager
Chris Kuruc, a Principal Product Manager

For a relatively small company, that started by the beach in Santa Barbara and that still operates outside the orbit of Silicon Valley, building a product as complex as Sonos One, in a short time frame, came with some inherent and unprecedented risks. Most daunting of all was the possibility that the user experience wouldn’t match the high expectations of customers. After wrapping up many months of concerted, almost frantic effort, the team collectively exhaled and awaited the response.

“The best-sounding smart speaker you can buy,” declared one reputable technology news site. “Alexa gets the sound quality she deserves,” wrote another. Almost across the board, the consensus started to emerge: Sonos One managed to combine voice control, flexibility and sound quality in a way that no one else had.

Michael Papish, Director of Platform Marketing
Michael Papish, Director of Platform Marketing

For Sonos, this achievement wouldn’t have been possible without an unprecedented effort on the part of multiple teams across the organisation, all of which flowed from the moment that they realised just how powerful voice could be.

“It was like magic,” Michael Papish, Director of Platform Marketing recalls thinking of voice control when the project began. Now there’s less mystique surrounding the technology, but that sense of wonder remains unshaken. “The real magic was in the teamwork and focus on the customer coming together in this technology that will keep getting better until it feels like it just disappears,” Papish continues. “We’re in a new world.”

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