For this to work you have to turn up your phone’s volume to max and set you Pocket operator to SY-4.
Turning your volume up to max is the most important thing. 99% of the time, if it doesn’t work, its because either your volume isn’t at max, or there’s some setting preventing it from being at max.
On iOS there’s a setting in “Sound & Haptics” on your phone called “Headphone safety” – in there, there’s an option for “Reduce loud sounds” – you’ll need to turn that off.
On some android phones you can enable “sound amplifier”, in Settings > Accessibility > Audio
From here I enabled “Sound Amplifier”. Make sure Amplifying is set to “sound on your phone” and then raise the boost parameter.
Also, if you’re on android make sure any third party apps that affect audio (e.g. some sort of EQ) or things like that are all turned off.
Unfortunately, all android phones are different, so some may have other settings you need to mess with to get the volume as loud as possible – look for anything to do with hearing protection. I wish I could buy every android phone and make individual instructions for each one but assuming each one cost $100, that would set me back $1,000,000, which I can’t afford at the moment.