Audio-Technica LS ATH-LS400iS

The ATH-LS400iS hits the 94th percentile for sound quality, making it one of the best-sounding in-ears in our database. But comfort, build, and usability scores are among the lowest we've seen for a product in this price tier. Unless $600 gets you into a pure audio nirvana and you don't mind a wire, you're likely better off with a feature-rich wireless alternative.

This is one of the best-sounding in-ears we've tested, landing in the 94th percentile for audio quality. That puts it ahead of nearly all wired and wireless buds in our database, which is frankly impressive for something that isn't a custom monitor. But that sound-first focus comes at a steep price: build quality lands in the bottom third, comfort in the bottom third, and the inline mic is below average. It's a specialist's tool.

If you're a music purist who wants analytical, reference-grade sound without an amp and doesn't mind a wire, the quad balanced armature setup here is stellar. Just know that the $598-$998 price bracket puts it smack in competition with feature-packed true wireless earbuds that offer active noise cancellation and app support. You're trading convenience for raw fidelity.

The quad balanced armature driver array, two for lows, one for mid, one for high, delivers outstanding detail and separation. Our measurements bear out the 94th percentile sound score: bass is tight, mids are articulate, and treble extends cleanly without sibilance. It's an analytical tuning that benefits well-produced tracks, and it'll embarrass plenty of IEMs costing over a grand.

The catch? Everything around that sound is mediocre. The plastic-heavy housing doesn't inspire confidence, and the fixed, non-detachable cable limits durability and replacement options. Comfort is hit or miss, with the 28th percentile ranking meaning you might not love it for long listening sessions. Still, if pure audio performance is the only metric you care about, this is near the top of the class.

Pricing swings from $598 to $998, which makes value a game of where you buy. At $598, you're getting near-summit-fi sound for the cost of a premium wireless bud, and that's a solid deal for a dedicated music player. At $998, you're stepping into custom IEM territory where better comfort and durability are standard. If you can snag them from a retailer like Newegg at the lower end with fast shipping, they're a niche steal; otherwise, the price balloon raises tough questions.

Stack these against the Sony WF-1000XM5 or Bose QuietComfort Ultra, and the Audio-Technica's 94th percentile sound score towers over Sony's 85th and Bose's 79th. But those true wireless buds bury the ATH-LS400iS in every other metric: ANC, comfort, connectivity, and build. The Sennheiser MOMENTUM True Wireless 4 and Technics EAH-AZ100 also offer better all-around scores. This is a one-trick pony; it outsings the lot, but if you need a daily driver for commutes or workouts, you'll hate the wire and lack of noise cancelling.

Fitness fans, commuters, and anyone who wants one pair of earphones for everything should steer clear. The fitness score sits at a dismal 15.3 out of 100, comfort is poor for moving around, and there's no sweat or water resistance. If you rely on active noise cancellation, wireless freedom, or all-day wear, you'll be thoroughly disappointed. This is strictly an at-home critical listening tool.

The ATH-LS400iS is a wired IEM for the sound extremist. Its 94th percentile audio performance is extraordinary, delivering detail and accuracy that trounce nearly everything in its path. But the poor build, middling comfort, and sky-high price make it a tough recommendation for anyone but the most dedicated sit-down listener. If you can find it around $598 and care only about music, grab it. If not, the latest flagship wireless buds from Sony or Sennheiser offer a far more livable package.