So, here's the short version: I've heard an upper midrange "clank" on the plain strings of all my guitars (PRS Standard 22, much modded MIM Strat, Eastman T386), especially the Eastman, since putting my current rig together. I play 99% of the time at home and at church in a "no stage volume / iso cab / IEM" situation, so I don't need much volume. Setup is guitar>pedalboard>Blackheart Little Giant head>Lopo 2x12. The speaker in the Randall iso cab is a Vintage 30. The "clank" doesn't happen with the iso cab, but there is so much other stuff going on in the signal path (mic, PA, etc), I never really connected the dots to the speaker. A few weeks ago, I took the Eastman (since it's the worst offender) to a local Fender/Peavey/Blackstar dealer and plugged into a bunch of amps. No clank. Gotta be my speakers, yes? The speakers in the cab, which I bought used at MGR for next to nothing, were Eminence model 12730 (used by Fender and, perhaps, Mesa), and carry no OEM branding. So...lucked into a couple of WGS speakers locally on FB, a Veteran 30 and a Reaper, in nearly new condition. The resulting tone is just fantastic! All the clank is gone, there's more volume (the WGS stuff is more efficient), and I can actually is the treble knob on my amp and pedals. I'd read here that speakers make a bigger difference than many expect - I'm a believer!