Here are some lesser known facts about wired headphones that I wish I had known earlier:

- there are TRS (3 rings) and TRRS (4 rings) connectors

- TRRS has integrated mic, also ofen implements playback control via buttons

- Apple headphones volume controls won't work on non-apple devices, because they implement a proprietary protocol based in an ultrasonic chirp authentication chip[1]

- 1more headphones seem to have implemented this auth protocol, but it does not work reliably

- Headphone remotes on apple devices have tap codes (in my opinion a huge benefit), that can be used to

  play/pause (.)
  next chapter / track (..)
  prev(...)
  fast forward (._)
  rewind (.._)
  even navigate menus (_, then + or -)
  
  ---- legend ----
  .=click
  _=hold 
  +-=vol
- The same tap codes are also implemented on hardware buttons (e.g. iPod) - while fast forward and rewind only work for devices iPod Nano 6th or later (iPod Classic 2009 only has next and prev)

- Apples USB-C 3.5 Adapters work with Android and iPhones and all headphones, Android does only implement play/pause and volume

- headphones remotes are fundamentally broken on Android because Google reserves longpress (button hold) for voiceover

- there are also balanced (often 4.4mm) outputs for much higher quality, often used in high res daps from fiio or shanling, etc

1: https://tinymicros.com/wiki/Apple_iPod_Remote_Protocol

Technically TRS only has one ring (Tip Ring Sleeve) and TRRS only has two rings (Tip Ring Ring Sleeve). It does have four separate contacts though, separated by bands.

That's correct... I meant this more visually :-)

i use an android app called keymapper (by sds100) that lets you remap the volume buttons so that a long press will change the track.

my wired earbuds only have 1 button on the in-line remote but the app can detect the button being pressed whether its a single, double tap or long press, and you can just assign whatever you want to them