How WWDC students made an app that turns iPhones into a surround sound system | Cult of Mac

How WWDC students made an app that turns iPhones into a surround sound system


Photo: Jim Merithew/Cult of Mac
Photo: Jim Merithew/Cult of Mac

While sitting in on a session at Apple’s Worldwide Developers Conference last year, Nick Frey, Chris Galzerano, and Veeral Patel got an itch to make something. As part of iOS 7, Apple had introduced “Multipeer Connectivity,” a framework for communicating with nearby devices.

Frey and his friends were at WWDC on student scholarships given by Apple, a tradition that provides the opportunity for hundreds of grade school and college students to attend the expensive conference for free each year.

Nearly a year later, the result of their shared itch is Audibly, a nifty iPhone app that can chain together iPhones to create a wireless sound system.

“We got up and left during the session from the front row because we were so excited to do something with the technology, and after some brainstorming this idea just came to us,” Frey told Cult of Mac, referring to when the idea for Audibly was born at WWDC last year.

By creating a peer-to-peer WiFi network that other iPhones can join, one person can play music from an iPhone and have it stream to all connected iPhones simultaneously. The host device acts as the broadcaster, and other devices join as listeners. Music needs to be locally stored on the broadcasting device for things to work smoothly.

One person can play music from an iPhone and have it stream to all connected iPhones simultaneously

“By the end of the week, we ended up having a really barebones prototype that played preinstalled songs with basically one device acting as a remote,” says Frey. “We demoed it to some engineers, and decided to keep going with the idea.”

Development of the app took longer than expected. But it gave the team an opportunity to dive into some of Apple’s core APIs and learn a lot about audio streaming, which Frey describes as an “immense learning experience.”

In an age where it seems like everything is connected via Bluetooth, it’s curious that Audibly works over WiFi. Frey and his team found that Bluetooth’s data transfer speeds are still not fast enough for streaming audio to multiple devices at once. But any iOS device that’s new enough to have a Lightning port can use peer-to-peer networking, which is much smoother for Audibly’s purpose.

At first glance, the idea behind the app, which launched in the App Store last month for free, seems a little gimmicky. But its creators and users have found some real use cases. Frey explains that one user plays the same music for he and his wife during their morning jog each day.

Frey lists a couple more scenarios where the app could come in handy. You could be sitting in class with headphones on and a group of people could listen to the same music from your iPhone. Long car rides with the family could be made more bearable by sharing music with your sibling in the backseat.

Get enough iPhones together in the right place, and Frey believes that Audibly could facilitate a party. “On a larger scale, you could output music to a line of cars with their stereos blaring and really make some noise.”


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