Hi Adam, thanks for the reply.
I don’t suspect it’s the capacitors in the crossovers. The problem was present before changing them over and the values were all correct in the replacement kit sent by Danish Sound Parts. My hope was that changing the capacitors would resolve the issue, but this has not been the case unfortunately.
I’ve taken a look at the foam previously and it looked good at first glance. I’ll try adding extra padding to see if this fixes the issue and report back.