Audio system pop on startup, 2018 Cooper S
 

Hello folks,
I've searched the various threads and not finding a similar issue.
We have a standard 2018 Cooper S, standard audio system. My wife noticed that on pressing the start switch, she'd get a loud pop from the audio system. The audio seems to work fine after that initial pop.
Could it be a loose connection somewhere? It doesn't seem to originate from a specific speaker.
The only way I can think to trace it may be to check the fuses, pull the radio (if easily done), check those connects or check for an audio module to see of those connections are tight. I'm pretty handy with a wrench and meter.
I'm open to any reasonable suggestions.
Thanks in advance for your help.
Cheers !