Apple looks to have worked out the balance issue with the little iPhone speakers. “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. 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.
The iPhone 7 & iPhone 7 Plus has not included the legacy headphone jack, causing some consternation by consumers post-release. The shift to the Lightning connector, and focused on wireless streaming and engineering considerations.
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.
“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.”