Updates: 9/16/19. Replaced 400i with updated Sundara. Added K240 to Budget Open Back. Added K712 to Open Back Top Tier. Added PM3 to Planar Magnetics. Replaced 600/650 with 6XX. Added HD599 to Mid-Tier Open Back. Added Table of Contents. 9/17/19. Grammar, spelling cleanup. 8/3/20. InnerFidelity and Tyll’s graphs all re-direct to Stereophile now, as the