Most of us judge a system on the music we already love.

That can be a trap. A rig voiced entirely on a jazz trio can sound like heaven on a jazz trio and fall to pieces on a full orchestra. Lean only on close-mic'd female vocals and you'll never discover that the bottom octave is a mess, because nothing you played ever went down there.

A cook who only ever makes one dish gets very good at one dish. Hand them a different cuisine and the gaps show instantly.

So feed your system everything. Orchestral and small ensemble. A solo voice and a wall of electronic bass. Acoustic guitar, where you can hear the pick on the string, and a dense rock mix that most systems smear into mud. Each kind of music stresses a different part of the chain, and the whole picture only shows up when you range across all of it.

One more thing, and it matters: use recordings that are actually good. A beloved track that happens to be badly recorded teaches you nothing except how to compensate for its flaws. Reach for reference-quality material—the Octave Records catalog was built for exactly this—so that what you're hearing is the system, not the mastering.

What does your system do with music you'd never choose on your own?

That's where it tells the truth.

Variety is the only test that can't be fooled.