One song I've heard that brings out flaws, distortion, and clipping is Outside the Glass - by The Black Heart Procession. Small band, but brought out the distortion in my z340s, muddy bass in yamaha 3-ways, and other flaws. It has moog synth far a bass effect and voice modulating (right term?). Another would be Nectars of Eden by Ebony tears. The songs phases through celtic music and hard rock, Really showing off flaws or perfection in treble and huge range. It really shows off tonal seperation in good speakers, bad ones turn it into a tidal wave of distorted guitar. Those are my suggestions. Happy hunting 😀.