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Harmon Kardon Onyx Studio 6

 & Tim Gideon Contributing Editor, Audio

Our team tests, rates, and reviews more than 1,500 products each year to help you make better buying decisions and get more from technology.

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Harmon Kardon Onyx Studio 6 - Harmon Kardon Onyx Studio 6
3.5 Good

The Bottom Line

If you like intense bass depth, the waterproof Harman Kardon Onyx Studio 6 will help you forget that it’s a fairly pricey mono speaker.
Best Deal£240

Buy It Now

£240

Pros & Cons

    • Intense bass depth and crisp highs
    • Handsome, waterproof design
    • Easy to operate
    • Heavy
    • Mono
    • No app or adjustable EQ

Harmon Kardon Onyx Studio 6 Specs

Bluetooth
Built-In Voice Assistant None
Channels Mono
Physical Connections 3.5mm
Portable
Water-Resistant

The Harman Kardon Onyx Studio 6 is portable, waterproof Bluetooth speaker that looks more like a design piece than something that can get soaked in the rain and continue working. Pricing for the Onyx Studio 6 is certainly confusing—a list price of $479.95 is replaced by permanent sale prices of anywhere from $200 to $300, including from Harman Kardon itself. At that lower price range, the speaker is a solid value. Anyone seeking an accurate mix should steer clear, but mega-bass lovers looking for rumble in a portable, outdoor-friendly design will be pleased.

Design

The Onyx Studio 6 is an upright, circular speaker with a cutout, rubberized handle, making it look like a designer handbag from some angles. Available in black, blue, or gray, the 11.2-by-11.5-by-5.0-inch (HWD), 6.5-pound speaker has considerable heft, so the handle is pretty much a necessity.

Almost hidden against the backdrop of the cloth grille is an array of rubberized black buttons, including Bluetooth, power, volume plus/minus, and a playback control that skips a track when pressed twice (but oddly doesn't navigate backward when pressed three times).

Below these controls, there’s a tiny status LED that shines through the grille, and an array of powerful drivers, including a single 4.7-inch woofer and a single 1-inch tweeter that combine for 50 watts and a frequency range of 50Hz to 20kHz. The speaker is compatible with Bluetooth 4.2, and supports the SBC codec only. Two Onyx Studio 6 speakers can be wirelessly connected to form a stereo pair

A covered port on the back protects the connections for the included power supply, as well as a 3.5mm aux input (no cable is included for that input). There’s also a micro USB service port.

An IPX7 rating means the speaker can technically be submerged up to a meter in water, though Bluetooth signal doesn't do well underwater. The point is, it should be fine poolside or in the rain. Just make sure the cover for the connections port is closed.

Harman Kardon Onyx Studio 6 in kitchen

Harman/Kardon estimates battery life to be up to eight hours, but your results will vary with your volume levels.

What's missing? The speaker has so much bass depth, an app with EQ would really have been helpful. And some users might might appreciate a speakerphone function—there’s no mic on the Onyx Studio 6.

Performance

On tracks with intense sub-bass content, like the Knife’s “Silent Shout,” the Onyx Studio 6 delivers palpable deep bass that will vibrate most of the surfaces you place it on. At top volumes, the bass doesn’t distort, though it does thin out a but—the DSP (digital signal processing) kicks in to prevent distortion.

For tracks that don’t have bonkers sub-bass like this one, but still pack some serious low-frequency punch—like nearly every track on the new Fiona Apple record, Fetch the Bolt Cutters—the Onyx Studio 6 still delivers thunder and then some. Luckily, it doesn’t overwhelm the mix, but playing the this record at high volumes has an almost live venue PA feeling to it, with intense bass on the kick drum hits.

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Bill Callahan’s “Drover,” a track with far less deep bass in the mix, gives us a better sense of the Onyx Studio 6’s general sound signature. The drums here sound like thunder, or a Godzilla-sized timpani. Low-frequency fiends will get their fix, but anyone seeking an accurate mix will be disappointed that there’s no app to dial things back. Luckily, the higher frequencies are still represented, so what we have is a somewhat balanced, hollowed out mix with powerful bass and sculpted highs to match.

On Jay-Z and Kanye West’s “No Church in the Wild,” the kick drum loop receives enough high-mid presence for its attack to retain its punchiness, but it also gets some serious added low-frequency heft. The sub-bass synth hits that punctuate the beat are delivered with slightly less intensity, though, so we know the limits of this speaker’s low-end. It can reproduce The Knife’s sub-bass to a degree, but it thins out at top volumes, and it has trouble reaching all the way down to get these really deep bass synth hits. But don’t worry, bass lovers: The rest of the lows are so dialed up you won't notice what’s missing. The drum loop here packs more low-end punch than it would in an accurate reproduction of this mix, by a wide margin. The vocals on this track are somehow not overwhelmed by all the added thunder—they sound crisp and clear, and lack much in the way of added sibilance.

You'd think that orchestral tracks, like the opening scene from John Adams’ The Gospel According to the Other Mary, might be in trouble through this speaker, but the bass doesn't sound quite as crazy on classical and jazz mixes as it could. The higher-register brass, strings, and vocals still retain the spotlight, but even if things are relatively balanced, this is a far from accurate sound signature.

Conclusions

From a purely sonic standpoint, the Harman Kardon Onyx Studio 6 delivers the kind of thump bass lovers are looking for. But in the portable, outdoor-friendly category, it has some worthy competition. The $400 JBL Boombox 2 is powerful and has stereo drivers, and we’re also fans of the $250 Sony SRS-XB43 and the $150 Sony SRS-XB33. All of these speakers can withstand water exposure, and some of them even put on LED light shows. But it’s hard to match the Onyx Studio 6’s main selling point: gonzo bass response. If that’s what you're after, you're sure to be happy.

Final Thoughts

Harmon Kardon Onyx Studio 6 - Harmon Kardon Onyx Studio 6

Harmon Kardon Onyx Studio 6

3.5 Good

If you like intense bass depth, the waterproof Harman Kardon Onyx Studio 6 will help you forget that it’s a fairly pricey mono speaker.

Get It Now
Best Deal£240

Buy It Now

£240

About Our Expert

Tim Gideon

Tim Gideon

Contributing Editor, Audio

My Experience

I've been a contributing editor for PCMag since 2011. Before that, I was PCMag's lead audio analyst from 2006 to 2011. Even though I'm a freelancer now, PCMag has been my home for well over a decade, and audio gear reviews are still my primary focus. Prior to my career in reviewing tech, I worked as an audio engineer—my love of recording audio eventually led me to writing about audio gear.

My Areas of Expertise

  • Headphones and earphones
  • Wireless and computer speakers
  • USB mics
  • Bluetooth headsets

The Technology I Use

Probably because of their prevalence in the recording studios I worked in a long time ago, I am most comfortable on Macs—I'm writing this on the 2019 iMac I use for testing. I also have a MacBook Pro that gets plenty of similar use.

My workspace has a mini recording studio setup, and the the gear I work with there is a mix of items I've used forever (Paradigm Mini Monitors and a McIntosh stereo receiver) and newer gear I use for recording and review testing (such as the Universal Audio Apollo x16).

I'm obsessed with modern boutique analog synths—some of my favorites instruments in this realm are the Landscape Audio Stereo Field and HC-TT,  the Soma Enner, the Koma Field Kit, and the Lorre Mill Keyed Mosstone.

From my studio days, I'm comfortable using Pro Tools, and in recent years have branched out to other realms of creative software, like Adobe Premiere and After Effects.

I stream music, but I also still buy albums, digitally or on vinyl, and encourage anyone who wants fair compensation for musicians and engineers to do the same.

I also play lots of Wordle.

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