Harman Kardon Onyx Studio 9 Review: Iconic Design Meets Refined Sound

The Harman Kardon Onyx Studio 9 continues the brand's tradition of creating speakers that are as much art pieces as audio equipment. The circular silhouette has become instantly recognizable, and this ninth generation maintains that iconic aesthetic while incorporating sustainable materials.

The speaker's construction uses 90% recycled aluminum for its distinctive circular ring, which gives the unit both structural integrity and visual appeal. The acoustic fabric covering the front and rear is now made from 100% recycled materials, demonstrating Harman Kardon's commitment to sustainability without compromising on premium feel.

Measuring 28.9 x 28.7 x 13 cm and weighing 3.33 kg, the Onyx Studio 9 strikes an excellent balance between substantial presence and portability. The integrated handle, cleverly hidden within the speaker's profile, makes it easy to move from room to room without disrupting the clean design lines.

The finish quality is exceptional. Every material feels carefully selected, from the matte aluminum frame to the precision-woven acoustic fabric. This is a speaker that commands attention in any room, serving as both a functional audio device and a conversation-starting design element.

Harman Kardon opts for minimalism with the Onyx Studio 9's physical controls. Six buttons line the top edge of the speaker: power, Bluetooth pairing, volume up/down, play/pause, and Auracast pairing. While the integration is subtle and maintains the clean aesthetic, these buttons can be challenging to locate by touch alone.

The LED indicator sits beneath the fabric on the front face, providing feedback on power status and Bluetooth connectivity. However, its discrete placement means it's often difficult to see in well-lit rooms. While this maintains the speaker's clean appearance, it can leave you guessing about battery level or connection status.

There's no voice assistant integration, which is a deliberate choice that keeps the speaker focused on its primary function: audio reproduction. For users who want Alexa or Google Assistant, this will be a disappointment. For those seeking a more analog, distraction-free listening experience, it's a welcome simplification.

The Onyx Studio 9 relies primarily on Bluetooth 5.3 for wireless connectivity, which provides stable connections up to 10 meters. The implementation is solid, with quick pairing and reliable performance throughout our testing.

The standout connectivity feature is Auracast support. This new Bluetooth standard allows you to pair multiple compatible speakers effortlessly. During testing, we connected the Onyx Studio 9 to a JBL speaker simply by pressing the Auracast buttons on both devices. The pairing was instant, and the synchronized playback worked flawlessly.

For wired connections, there's a 3.5mm auxiliary input on the rear, along with a USB-C port. The USB-C port serves dual purposes: charging the speaker and providing power to charge your devices. It's a thoughtful inclusion that adds versatility to the setup.

The Harman Kardon companion app (available for iOS and Android) offers basic but useful functionality. You can adjust EQ settings with a 7-band graphic equalizer, manage stereo pairing, and access preset sound profiles. The app is straightforward and responsive, though it lacks the depth of features found in some competitor apps.

What's notably absent is any form of network streaming. There's no Wi-Fi, no Spotify Connect, no AirPlay, and no Chromecast support. This positions the Onyx Studio 9 firmly as a Bluetooth speaker rather than a connected audio system. For users invested in multiroom audio ecosystems, this is a significant limitation.

The Harman Kardon Onyx Studio 9 delivers impressive audio quality that prioritizes balance and naturalness over aggressive sound signatures. The speaker uses a single 120mm bass driver complemented by three 20mm tweeters, powered by 50 watts of total RMS output.

The bass response is well-controlled and present without being overwhelming. Low frequencies extend surprisingly deep for a speaker of this size, providing satisfying rumble in electronic music and weight to acoustic bass instruments. Importantly, the bass never bleeds into the midrange or creates muddiness.

Midrange reproduction is the speaker's strongest suit. Vocals sound clear and natural, with excellent detail and presence. Instruments occupy distinct spaces in the soundstage, creating a sense of separation that's impressive for a single-unit speaker. Whether listening to jazz, classical, or rock, the midrange maintains clarity even at higher volumes.

The high frequencies are smooth and refined, though they could use a bit more sparkle. Cymbals and high hats are present but somewhat recessed compared to the rest of the spectrum. This creates a warmer, more relaxed presentation that's easy on the ears during extended listening sessions but might disappoint those who prefer a brighter sound signature.

The automatic room calibration system deserves special mention. The speaker uses internal microphones to analyze your room's acoustics and adjusts its output accordingly. In testing, we noticed genuine improvements in bass response and overall balance when moving the speaker between different rooms. The system effectively compensates for acoustic challenges in smaller or more reflective spaces.

Stereo imaging from a single unit is naturally limited, but the Onyx Studio 9 does better than many competitors thanks to its driver configuration. There's a sense of width to the soundstage, though creating a true stereo pair with a second Onyx Studio 9 would dramatically improve the spatial presentation.

Volume capabilities are excellent. The speaker can fill large rooms without strain, maintaining composure and clarity even when pushed to maximum levels. Distortion only becomes apparent at truly unreasonable volumes.

The Onyx Studio 9 packs an internal battery rated for 8 hours of playback. In real-world testing at moderate volume levels (around 25%), we achieved approximately 10 hours before needing a recharge. Push the volume higher, and that figure drops closer to the manufacturer's claim.

For a speaker of this size and weight, 8-10 hours is adequate but not exceptional. Competitors in this category often offer 12-15 hours or more. Given that the Onyx Studio 9 is designed more as a portable home speaker than a true outdoor companion, the battery life is acceptable for moving between rooms or occasional outdoor use.

Charging happens via USB-C, which is convenient for compatibility with modern chargers. A full charge takes approximately 5 hours. There's no fast charging support, which would have been a welcome addition.

The USB-C port can also charge your devices while the speaker is plugged in, turning it into a charging station for your phone or tablet. It's a nice bonus feature that adds versatility.

Battery level indication is only available through the companion app, as there's no clear visual indicator on the speaker itself. This can leave you guessing when you're away from your phone.

At £250, the Harman Kardon Onyx Studio 9 sits in the premium tier of Bluetooth speakers. You're paying for the iconic design, quality construction, and refined sound signature. Compared to competitors at similar price points, the Onyx Studio 9 trades connectivity features for superior aesthetics and build quality.

The use of recycled materials throughout adds value for environmentally conscious buyers, and the timeless design means this speaker won't look dated in a few years. The automatic room calibration is a genuinely useful feature that improves real-world performance.

However, the lack of Wi-Fi streaming and smart features does limit its versatility compared to similarly priced alternatives. If you need multiroom audio or voice control, you'll need to look elsewhere.

The Harman Kardon Onyx Studio 9 excels at being a beautiful, well-engineered Bluetooth speaker with excellent sound quality. It doesn't try to be a smart home hub or a multiroom audio solution. Instead, it focuses on doing one thing very well: playing music with balance, clarity, and style.

The automatic room calibration system works impressively, the build quality is exceptional, and the sound signature will please audiophiles who value neutrality over excitement. Auracast support future-proofs the connectivity options while maintaining simplicity.

The limitations are real: no Wi-Fi, no voice assistant, and moderate battery life. But if these aren't dealbreakers for your use case, the Onyx Studio 9 delivers a premium audio experience wrapped in one of the most attractive speaker designs available. It's a speaker that earns its place in your home through both performance and presence.