When you pick up a pair of Koss's Pro4AA Titanium headphones, you'll know they're something special. The $99 model weighs a substantial 21 ounces, and that inspires confidence in its build quality. Its titanium-coated, high-polymer diaphragms promise accurate sound, and the ear cups' Pneumalite cushions provide maximum bass and isolation from your environment. While the extrasquishy pads certainly promote a tighter headphone seal, they can be uncomfortable in warm weather. Like its step-down brother, the Pro3AA, this model's coiled 8-foot cable is fitted with a 1/8-inch stereo miniplug, but a screw-on 1/4-inch adapter is included for use with home stereos.
We watched a few DVDs to check out the Pro4AA's sound. Phone Booth is a fascinating thriller about a psycho sniper taunting a man in a pay phone. The headphone's exacting precision took us deep inside the mix, so we heard sonic details lost over all but the very best speakers. For example, we were aware of the claustrophobic sound of the booth, and the more open quality of the other actors' voices. Ah, but when we compared the 4AAs to the Pro3AAs, we preferred the less expensive model. Yes, the 4AAs were more detailed, but the 3AA's top-to-bottom balance was superior.
We repeated the comparison with CDs and again preferred the 3AAs. Morphine's The Night CD has a huge bass sound, and it came over the 3AAs with greater definition and impact; the 4AAs had oodles of bass and top-end detail, but the midrange was recessed, which rendered comparatively thin-sounding vocals. However, that's our taste; we're sure some listeners will opt for the Pro4AA's punchier sound.