Apple's new stereo sound implementation on the iPhone 7 series of phones utilizes the bottom speaker in conjunction with a balanced earphone on the device, instead of a second edge-mounted speaker.
With the iPhone 7 family, Apple has implemented stereo on-device for the first time. Apple hasn't published full speaker specifications yet, but claims that the new speakers deliver two times the volume of the iPhone 6s, and "increased dynamic range."
AppleInsider has spoken with several audio engineers, and all of them agree that Apple's implementation of on-device stereo will be good enough for close listening, but the stereo channels will be indistinguishable at a range of greater than about four feet from the device.
"From what I've seen, Apple looks to have worked out the balance issue with the little iPhone speakers," one engineer told us. "If you want consistent stereo channel separation from any phone, though, stick with headphones."
The iPhone 7 Plus has a slightly wider distance between the speakers than the iPhone 7. We were told by the engineers we asked that it would make no appreciable increase in the maximum range from the phone that users would still be able to pick out discrete stereo channels.
AppleInsider will be examining the stereo performance as soon as possible.
"If you're listening to your music on any phone's speakers or most Bluetooth streamers, you're not that concerned about audio quality, generally."
The iPhone 7 has not included the legacy headphone jack, causing some consternation by consumers post-release. A post-release interview by Apple Senior Vice President of Worldwide Marketing Phil Schiller and Senior Vice President of Hardware Engineering Dan Riccio explained the shift to the Lightning connector, and focused on wireless streaming and engineering considerations.
Beyond just internal space considerations on the iPhone, reliance on the Lightning connector for audio out opens up possibilities for higher bitrate audio, and lossless streaming to external devices. Legacy Bluetooth devices are supported by the new W1 wireless chip, and vice versa — a W1-equipped speaker set can sync to conventional Bluetooth phones as well.
"Most Bluetooth speakers are compact, with decent sound, but lack channel separation," we were told by the same engineer. "If you're listening to your music on any phone's speakers or most Bluetooth streamers, you're not that concerned about audio quality, generally."