Many of the portable Bluetooth speakers we test are rugged and made for outdoor use, but the Harman Kardon Onyx Mini feels more like a portable speaker for the house. At $199.95 it’s not cheap, but it delivers audio worth the price. You won’t be getting booming subwoofer-like bass out of the Onyx Mini, but it packs a rich, full low frequency response, along with excellent higher frequency clarity. For its size, the speaker gets exceptionally loud, and does so without distorting. Throw in speakerphone functionality and a thoughtful design that includes upward-angled drivers, and there’s plenty to like here, earning the Onyx Mini our Editors’ Choice award.
Available in a black, blue, or gray design that measures 5.7 by 6.2 by 3.7 inches (HWD) and weighs 1.3 pounds, the Onyx Mini has a circular, convex front-facing panel that is covered entirely in speaker grille, with the Harman Kardon logo featured prominently across the center. Behind the grille, the speaker’s dual 45mm, 8-watt drivers are angled slightly upward, making the Onyx Mini a solid choice for a desktop or tabletop speaker, as the audio is more aligned with your ears than it would be if the drivers fired straight outward. While this is technically a portable speaker, there’s no pouch or tote included, nor is it necessarily meant for outdoor use—think of it as portable in the room-to-room sense.
The back panel and flat base are covered in a matte rubber material, with a passive bass radiator situated at the center of the back panel. Along the top of the speaker are controls for power, volume (which works in conjunction with your mobile device’s master volume levels), Bluetooth pairing, and a Telephone button for utilizing the speakerphone function. There’s a battery indicator LED at the top of the back panel, near the controls. At the bottom of the back panel, there’s a 3.5mm aux input (though no audio cable is included—an annoying oversight given the price) and a micro USB port for the included charging cable. The cable can charge the speaker via a USB computer connection, or with the included USB power adapter.
We are nitpicking here, but it might have made more sense for the Telephone button to have a different kind of marking—if you don’t look at the manual first, you might not realize that it is also the play/pause button, as well as the track navigation button, depending on how many times you tap it. In other words, it’s a typical multifunction button (and it’s great that you can skip tracks and pause music), but labeling it with the telephone icon seems like an odd choice.
If you buy two Onyx Minis, you can link them and make one the left and one the right speaker for true stereo separation. This is easily accomplished by holding the Bluetooth button in for five seconds.
Harman Kardon estimates battery life to be up to 10 hours, but your results will vary based on your volume levels and your mix of wireless and wired playback. The speaker will automatically re-pair with the most recently paired in-range mobile device when powered up.
For starters, the relatively small Onyx Mini can get impressively loud. On tracks with imposing levels of sub-bass, like The Knife’s “Silent Shout,” the speaker doesn’t distort, but it definitely sounds like its drivers and radiator are being pushed to the brink at top volumes. Also, the deepest bass on this track sounds relatively thin through the speaker—it’s the more moderate bass ranges, above 100Hz, say, that sound more powerful through the Onyx Mini. At those levels, the speaker delivers a solid amount of bass punch, and the lows are well balanced with high frequency presence.
Bill Callahan’s “Drover,” a track with far less deep bass in the mix, gives us a better idea of the Onyx Mini’s overall sound signature. The drums on this track can easily sound too powerful and thunderous on heavily boosted systems, but here, they take something of a backseat—they don’t receive added sub-bass depth because it seems the Onyx Mini doesn’t reach down that low. The speaker is still capable of providing a rich bass experience, however—Callahan’s baritone vocals have a commanding presence through the Onyx Mini’s drivers. The lows and low-mids, therefore, seem dutifully represented, while the frequencies typically handled by subwoofers are less a part of the equation. This isn’t surprising—the Onyx Mini isn’t large enough to really deliver that kind of low-end thump. It does well with the bass it can reproduce, however, so that despite having a strong high-mid and high frequency presence (lending some nice treble edge to the vocals and the guitar strums), the mix sounds balanced and full, not thin.
On Jay-Z and Kanye West’s “No Church in the Wild,” the kick drum loop gets an ideal level of high-mid presence, highlighting its sharp attack and allowing it to slice through the mix as a prominent force. The loop also gets plenty of bass thump, while the sub-bass synth hits that punctuate the beat are delivered with a little less intensity—we get a decent sense of their depth, but we hear more of the higher frequency raspy edge to the hits. All three vocalists on this track have a clear presence through the Onyx Mini—there’s never any added sibilance, and despite the beat’s powerful presence, it never feels like the vocals are doing battle with it for the spotlight.
Orchestral tracks, like the opening scene in John Adams’ The Gospel According to the Other Mary, get an added low frequency presence that brings the lower register instrumentation a little forward in the mix—but not so much that they graduate beyond their supporting role. The higher register strings, brass, and vocals have commanding high-mid and high frequency presence through here. It’s a bright sound, with plenty of anchoring in the lows, but nothing in the bass department gets boosted to unnatural or ridiculous levels.
The Harman Kardon Onyx Mini is one of the better desktop Bluetooth speakers we’ve tested lately. It delivers a very healthy bass response in the above-100Hz realm, and thus sounds quite rich. Pair that with bright, crisp high frequency response, and you end up with a very pleasant balance—and powerful performance for the size. If you’re looking for more bass depth, consider something a bit larger, like the Marshall Kilburn or JBL Xtreme. If portability is more of a concern, the B&O Play Beoplay A1 and the less expensive Sony SRS-XB3 are both more portable, outdoor-friendly models. That said, the Onyx Mini gets just about everything right, and earns our Editors’ Choice.