Zoe at ProAc Loudspeakers UK and Bryce Allan at The Sound Organization (US ProAc importer)
I'm probably starting to sound like a broken record by this point, but Zoe at ProAc UK and Bryce at The Sound Organization in the US have been incredibly helpful in my search for a suitable replacement for my long-departed Response 1SCs (selling them was one of the dumbest things I ever did). They were more than willing to provide timely, knowledgable advice even when I asked them about now-discontinued models that I was considering purchasing used. Both are terrific representatives for the storied UK brand.
A year or so back, I reached out to The Sound Organization looking for replacement drivers for my ProAc speakers. I'm still waiting. I'm glad your experience was more satisfying than mine.

