Samsung
Change Ringtone for Calls auf Samsung
The default call ringtone on Samsung phones is buried in the sound settings, not in notification settings, which is why many people never find it.
To change it, go to Settings ➔ Sounds and vibration ➔ Ringtone. This screen lists all built-in ringtones and lets you preview each one before applying it.
On a dual-SIM device, Samsung shows a SIM picker first: Choose a SIM card (Dual SIM). Each SIM line keeps its own ringtone, so switching the tone for SIM 1 will not affect calls coming in on SIM 2. This is useful if you want to hear instantly which number is ringing without looking at the screen.
After picking the card, tap Set a Ringtone to confirm your choice. Custom audio files do not appear in this list automatically. They need to be copied to the phone storage first, usually into a Ringtones or Music folder, before the system recognizes them as selectable tones.
If the ringtone still does not play during incoming calls after this, check that the ringer volume is turned up and that Do Not Disturb or a Focus mode is not muting calls separately.