Test results were nothing short of shining, with zero audible distortion, an expertly balanced frequency response, huge isolation numbers, and a handful of other great marks to boot.
The AKG K 323XS in-ear headphones (MSRP $59.95) are as portable and sleek as they come. Pop them in and treat yourself: The XS produces huge sound marked with prominent bass, supportive mids, and very healthy highs.

Moreover, these are some of the best passive isolators I've ever tested, and I didn't measure even a speck of audible distortion. High-five, AKG: These things are top-to-bottom winners.

When measuring and assessing a frequency response, we're determining how a set of headphones emphasizes various notes along the audible listening spectrum. In this case, we found a very balanced sound profile that's sure to satisfy plenty of listeners.

Instead of blasting volume throughout bass and sub-bass regions (a trend for many consumer headphones), the XS produces more of a flat response. Meanwhile, mids and upper mids dip slightly in volume, and very high notes get a boost in emphasis. The resulting shape mimics an equal loudness curve (ELC), or one that emphasizes all frequencies in a such a way as to equalize them in volume for the human ear.

The XS's soundscape therefore has firm bass support, and lots of detail throughout the middle and high range, as well: tiny headphones, really big soundstage.

A win for the busy listener

These AKGs are tiny, good-looking, and comfortable enough for most. We tested the white pair, but they also ship in blue, orange, yellow, green—the list goes on. Aesthetics aside, if you're searching for the perfect travel companion, you'll want to give these a close look. In fact, the XS are a friend to commuters and athletes alike.

The form is just perfect for multitasking in general: The Android version packs a one-button universal remote, and there's also a three-button version for iOS. The XS's teeny form factor, featherweight frame, and small carry case are additional on-the-go perks.

Users get four different speaker covers.

The cable is simple, but of decent quality. It's shorter than most cords—just 3.5-feet long—which makes it very manageable for busy listeners. There could be better reinforcements around the jack and earpieces, though, so definitely keep these AKGs wrapped up in their carrying case for safekeeping.

Users get four different speaker covers, too: extra small, small, medium, and large. Take note, Goldilocks.

Tester's pet

Basically, the XS in-ears do everything right. Time in the lab revealed a straight-A student: I discovered solid engineering, and just all-around great performance.

Listeners will enjoy big, thumping bass that doesn't obscure subtler instruments like violin.

Thanks to moderate bass notes and very prominent middle and high notes, music sounds both full and balanced. From classical, to jazz, to hip hop, every genre benefits from this even-handed sound quality. Listeners will enjoy big, thumping bass that doesn't obscure subtler instruments like violin and piano.

These tiny in-ears aced distortion tests, too—you won't find one drop of unwanted or distorted sound on the XS. They balance volume properly in the left and right speakers, and the isolation results crushed it. The amount of outside noise that these things block is comparable to some sets of active noise cancelers—very impressive.

Part of the XS's high score is on account of its distortion test results: These are phenomenal measurements. In general, we hope to find no more than an average of 3% total harmonic distortion throughout the entire spectrum, but the XS keeps that number below 1%.

That means that at no point along the response will listeners ever hear any unwanted garbage in their music—no clipped notes, no added mechanical noise, just pure, clean tunes.

Of course, if you have no sense of precaution and you crank tunes upwards of 107dB, that measurement climbs to above the 3% mark. Just practice safe listening and this won't be a problem.

Talk about a noise-blocking beast—the XS blocks the kind of noise that you'd normally need active noise cancelers for. On average, these tiny headphones block 28dB of outside sound.

Specifically, bass noises like rumbling vehicles are reduced by more than half. Midrange outside sounds are shrunk to more than 1/4 their original loudness, and very high-pitched bothers are hushed to more than a whopping 1/32.

Premium product, perfect price

The K 323XS really shines, even in a crowded market. It's hard to pick which glowing attribute to praise first: The massive, well-balanced sound stage? The distortion-free listening experience? The $59 price tag? The monster isolation? The tiny, portable design? These AKGs are simply Aces, and online sale prices of around $40 kick everything up another notch.

If you're searching for ultimate durability, removable cables, or piles of flashy extras, you'll want to keep shopping.

Then again, you've got to tip your hat to a soundstage this big and balanced from something this tiny and inexpensive.

Other Tests...

Meet the testers

Virginia Barry

Virginia Barry

Former Managing Editor

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Virginia is a former Managing Editor at Reviewed.com. She has a background in English and journalism. Away from the office, Virginia passes time with dusty books & house cats.

See all of Virginia Barry's reviews

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We use standardized and scientific testing methods to scrutinize every product and provide you with objectively accurate results. If you’ve found different results in your own research, email us and we’ll compare notes. If it looks substantial, we’ll gladly re-test a product to try and reproduce these results. After all, peer reviews are a critical part of any scientific process.

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