Issue Connecting Boya BY-M1 Mic to iPhone 15 via Type-C Adapter

The core of the problem lies in how the mic outputs its signal and how Apple’s USB-C to 3.5mm adapter handles audio input. The BY-M1 outputs a TRRS (4-pole) signal designed for analog mic input, which worked fine with the Lightning adapter because it had built-in analog audio pass-through. But with the USB-C adapter, Apple seems to be treating that port as digital only, or it's just not offering full TRRS mic support like before.

In addition, the Boya BY-M1 is a powered mic that uses the TRRS configuration to route the mic signal properly, but the iPhone 15’s USB-C adapter likely expects either a digital mic or a headset with a mic that follows Apple’s specific signaling expectations. That mismatch causes the mic to be ignored or not recognized at all.

One potential workaround would be to try using a USB-C audio interface that explicitly supports TRRS analog input, such as the Sabrent USB-C External Stereo Sound Adapter or something from RØDE (like the AI-Micro).