iPhone vs. Android via USB-C sound quality difference is huge

[2leftears]

Throughout this thread, I had no idea what was being discussed because the wrong word was being used. Of course a difference in sound between two devices might likely be due to a software issue in a DSP. But a "cable" shouldn't be having software issues.

Yes, calling it a dongle would have been more appropriate I think. But the OP was quite clear in their first post that they were talking about a USB cable with integrated DSP.

These days there are quite a few "cables" that have some active protocol conversion circuitry or other active circuitry hidden inside one of the plugs, because they can be made so small. Remarkable really: the circuitry that fits unnoticed inside a modern cable plug can be more computationally powerful than a desktop computer from the 80's...

 

[CK Moustache]

I haven't read the entire thread but only skipped through some of it.

Imo these two scenarios are quite possible:

• Either of the smartphones applies some processing to the digital signal before it is sent to the DAC. Quite likely actually. That's also why the maximum volume is lower from the iPhone than from the Android device.
• The iPhone puts out less power through its USB-C port and the DAC dongle is therefore in a different gain mode and you've just not fully volume-matched to the Android device wherefore the sound is slightly quieter and therefore perceived as less dynamic.

If you want to, you can play around with RMAA and Audacity and see if there's a difference in basic things like frequency response, distortion or volume in general. Just see my post in this old thread of mine (no need for a y-divider/split cable or connecting the headphones for this test, just use the bare dongle DAC, just the test files, a sound card/mic input, a 3.5 mm male to 3.5 mm male cable and free software are necessary): https://www.head-fi.org/800208/#post-12386879

Never mind, forget what I just wrote. After I had posted this, I realised that the DAC is integrated into the IEMs' cable itself, therefore you cannot measure the output with the method I linked to.