From 23:48 on he compares the four speakers one by one with a 57 with astonishingly different results. I wonder if the weaker sounding speaker is even in a good working order. Is this a quality issue with Celestion nowadays or what? Aren't they supposed to sound more or less the same? And it clearly couldn't have been the issue of "not being broken in yet" as all four are in the same cab that must have gotten its fair share of studio use.