“Then, it’s just as simple as looping over the mp3 files, and if it’s contained in the image, running mp3gain on the file and then replacing it in the image with the gain-modified version. I used an adjustment of -19.5 decibels.”
Tozo’s T6 earbuds blast a pairing chime with no volume control, and Tozo said there was nothing it could do. The fix took sniffing the app’s traffic, identifying an Airoha AB1562 chipset through a Reddit clone-AirPods community, and patching mp3 files inside the firmware image. The vendor’s own update server handed over the firmware. A few changed bytes did what customer support said was impossible.