The Harman/Kardon Onyx Studio 9 is a sleek, portable wireless speaker that's meant for at-home use. Its battery and built-in handle make it easy to carry from room to room, and its understated oval design means it will look at home in many different interior decor styles. Like its predecessor, the Harman/Kardon Onyx Studio 8, its dual-tweeter design means it can playback stereo audio without downmixing to mono, and support for Bluetooth multipoint lets you pair it with two devices at once. But the Studio 9 brings added support for a companion app, making it easier to customize its sound to suit your preferences.
Our Verdict
The Harman/Kardon Onyx Studio 9 is okay for listening to music. Due to its size, it's lacking in low-frequency extension, but there's some compensatory emphasis in the low-mids that helps conceal the lack of bass. At higher frequencies, its tuning is balanced, with a bit of extra sparkle in the high-treble. It automatically adjusts to suit your room, and has a bass/treble slider and a built-in EQ. It supports stereo playback and will get loud enough to fill average-sized indoor spaces. Its forward-facing design also means you'll want the speaker facing you for the best sound.
Stereo playback.
Room correction feature.
Forward-facing speaker means sound quality depends on your listening angle.
Compresses bass at high volumes.
The Harman/Kardon Onyx Studio 9 is acceptable for watching movies. It gets loud enough to fill an average-sized room with sound but probably isn't the best choice if you have a larger space. Its frequency response also lacks bass output, so explosions sound anemic rather than rumbly. The speaker automatically adjusts itself to suit your room and also supports stereo playback, allowing stereo positioning information to come through. Latency is low when paired with iOS, but quite high with Android, which may cause lip-sync issues. However, different apps and devices compensate for latency differently, and you can always use the AUX port to get low-latency playback via a wired connection.
Stereo playback.
Room correction feature.
Forward-facing speaker means sound quality depends on your listening angle.
Compresses bass at high volumes.
The Harman/Kardon Onyx Studio 9 is very good for listening to podcasts. The virtually flat mid-range ensures voices sound true to life, and it gets loud enough to fill a medium-sized room. Since it's battery-powered and has a built-in carrying handle, it's easy enough to take with you between rooms. It's a front-facing speaker, so you'll probably want to make sure it's facing you, which might be annoying in some circumstances, but it supports multi-device pairing, so switching between two different playback devices is easy.
Stereo playback.
Room correction feature.
Built-in carrying handle.
Mediocre battery performance.
Forward-facing speaker means sound quality depends on your listening angle.
The Harman/Kardon Onyx Studio 9 doesn't have a built-in microphone.
The Harman/Kardon Studio 9 is not really meant for use outdoors as it's not rated for dust and water exposure, and its six-hour battery life won't get you through a full day at the park. That said, provided you keep it protected from the elements, it'll work well enough in your garden or on your balcony. Just don't expect it to get the party started at your next BBQ, as it doesn't get very loud.
Stereo playback.
Built-in carrying handle.
Mediocre battery performance.
Forward-facing speaker means sound quality depends on your listening angle.
Changelog
- Updated Jul 28, 2026: This review has been updated to Test Bench 1.0.1. This includes the Test Bench 1.0 updates to all of our Sound tests: Frequency Response Accuracy, Raw Frequency Response, Directivity, and Loudness, as well as the revised Low-Frequency Extension calculation and related DRC updates introduced in Test Bench 1.0.1. There have also been text changes throughout the review, including to the usages and product comparisons, where applicable, to match these results. You can read more about these changes in our Test Bench 1.0 changelog and Test Bench 1.0.1 changelog.
- Updated Jul 13, 2026: This review has been updated to Test Bench 1.0, which includes new results for all of our Sound tests: Frequency Response Accuracy, Raw Frequency Response, Directivity, and Loudness. There have also been text changes made throughout the review, including to the usages and product comparisons, to match these results. You can read more about these changes in our changelog.
- Updated Apr 14, 2025: Review published.
- Updated Apr 08, 2025: Early access published.
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Differences Between Sizes And Variants
The Harman/Kardon Onyx Studio 9 comes in two color variants: 'Black' and 'Grey.' We tested the 'Black' variant, and this is its label.
If you encounter any other variants of this speaker, please let us know in the comments, and we'll update our review accordingly.
Popular Speaker Comparisons
The Harman/Kardon Onyx Studio 9 is a sleek and stylish portable home speaker. It's the follow-up to the Harman/Kardon Onyx Studio 8 in a more understated design. The arresting wraparound handle of the Studio 8 is gone, replaced with a more traditional aluminum band that frames the speaker. Still, the Studio 9 brings added support for a companion app that lets you tweak the sound to your liking, and its more traditional design means it takes up less shelf space. If you like Harman/Kardon's balanced sound profile but want a bit more volume, the Harman/Kardon Go + Play 3 is larger and heavier than the Studio 9 but gets quite a bit louder.
Unlike other home speaker brands, Harman/Kardon doesn't tend to include contemporary niceties like voice assistant support, so you'll want to consider something like the JBL Authentics 500 if that's important to you. And none of the Harman/Kardon speakers we've tested are meant for outdoor use, so you'll want to consider speakers from other brands, such as Bose and Ultimate Ears, if you plan to take the speaker outside. The Bose SoundLink Max and the Ultimate Ears EPICBOOM, both rated IP67 against dust and water ingress, are great alternatives.
Check out our recommendations for the best portable Bluetooth speakers, the best home speakers, and the best Bluetooth speakers.
The Harman/Kardon Go + Play 3 is about double the size of the Harman/Kardon Onyx Studio 9, so it's probably unsurprising that it gets a lot louder and has a more consistent bass response. Both of these speakers have sleek yet understated designs that should suit most rooms in your home; their lack of IP ratings means you won't want to take them outside, anyway. They also both have loosely balanced frequency responses that suit a wide variety of audio, from podcasts to music. But if you like to tweak your speaker's sound, you'll want the Studio 9 as it comes with a companion app with a 7-band graphic EQ.
The JBL Boombox 3 and the Harman/Kardon Onyx Studio 9 are meant for different purposes. The JBL is a sturdy, water-resistant boombox that can accompany you on long park hangs or BBQs in your garden, while the Harman/Kardon is a sleek speaker meant to live indoors. Both come with companion apps so you can customize their sound profile. The choice really comes down to your usage here.
The Harman/Kardon Onyx Studio 8 is the predecessor to the Harman/Kardon Onyx Studio 9. Where the Studio 8 stood out for its arresting design, with the entire speaker framed by an aluminum wraparound handle, the Studio 9 has a more traditional, laid-back oval design. Both speakers are easy to carry around your house and sound fairly similar. The main difference is the addition of companion app support to the Studio 9, giving you access to a 7-band EQ to tweak the sound to your heart's desire.
The JBL Authentics 500 and Harman/Kardon Onyx Studio 9 have different strengths. The JBL is quite a bit larger than the Harman/Kardon, so it unsurprisingly gets much louder. That said, the Harman/Kardon is battery-powered and easy to carry around with you, though we wouldn't take it outside as it lacks an IP rating against water and dust ingress. The JBL has a built-in mic, so it's the one to choose if voice assistant support is crucial to you.
Test Results
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