Koss was founded in 1958, so it’s as old-school American hi-fi as you can get, and I’d bet lots of older audiophiles have fond memories of their Pro4AA headphones from back in the day. Koss still makes that headphone, and sound-wise, it’s about as subtle as a 1970 Chevelle SS 396 muscle car. As for this new Pro4S, it’s closer to a new Camaro—the sound is far more refined. The sharply sculpted, cast-aluminum ear cups are the first clues; the handsome design has a contemporary look and feel. The sound balance was just a tad warm, but the Pro4S wasn’t lacking in resolution as I played familiar tunes. The sound was right on the money. Not only did my audiophile tracks from Reference Recordings, MA Recordings, and Chesky sound open and clear, the harshest, most overcompressed downloads didn’t tear my ears off. The Pro4S lets the music speak for itself.
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