DIAGNOSIS Trueplay is hypersensitive to background noise and needs a very specific environment. Common culprits are HVAC systems, fans, fish tanks, refrigerators cycling on, or even too much hard furniture in the room.
FIX Do it at the quietest time of day. Turn off all air conditioners, fans, and humidifiers. Close the windows. Put your phone on silent, not vibrate. Hold your iPhone naturally at ear level while walking around—don't cup the phone or cover the mic array. Walk slowly and deliberately through the entire space.
IF THAT DIDN'T WORK The Beam Gen 2 only supports Trueplay tuning with iOS devices. If you're trying with an iPad, make sure it's a model with the necessary microphones (most do). Android phones cannot perform Trueplay tuning, period. Also, ensure your iPhone's iOS is up to date.
HEADS UP If you have thick carpets and curtains, Trueplay might actually make the sound too dull for your taste. You can always turn Trueplay off in the app after tuning. It's not a mandatory setting.