Moondrop - Aria 2 vs Sennheiser - IE 600

The Aria 2 edges ahead on the Mars Score (65.4 vs 61.5), but the 3.9-point gap is small enough that the right pick comes down to which spec advantages matter to you.

Pick the Aria 2 if you care most about sensitivity. The biggest gaps in its favor are sensitivity. The single most decisive one: Sensitivity — 3.39% more. 122 dB vs 118 dB.

Pick the IE 600 if you care most about impedance. Its strongest claims are impedance. The single most decisive one: Impedance — 14.00 Ω less. 18 vs 32.

Both ship with comparable driver count, detachable cable, so those specs do not separate the two — focus on the differences below.

Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.