Front speaker open circuit found in VCDS

[HPsauce]

I rarely have the radio (or music) on so hadn't noticed anything amiss.
SatNav directions were sounding normal.

Testing the speakers by changing balance and fader I've narrowed it down to the nearside front (door) speaker(s) which are producing just a faint tinny sound.
Drivers side is good as are the rears, which is why I hadn't really noticed.

Where would you start trying to track down and fix this. Have the RNS out and reseat the speaker plugs first?
I can't recall exactly how the plugs fit but I don't expect it's easy to swap left and right.

Note: Probably relevant/important that this is NOT a Bose system so I think the front speakers are driven directly by the RNS.
So it should be the 8-pin connector next to the multi-block/multi-colour connector and specifically the pair nearer the fuse.