These sit in different size classes, so this is not a straight ranking comparison. The Teufel Rockster Cross ranks #23 of 82 large speakers by sound quality at $199.99; the Harman Kardon Onyx Studio 9 ranks #15 of 76 boombox speakers by sound quality at $189.99.
What the Teufel Rockster Cross does well: Pretty neutral frequency response. The tradeoff: Outdoor mode can sound somewhat harsh due to the 4kHz peak.
The case for the Harman Kardon Onyx Studio 9: An elegant 4.2kg living-room portable with a measured 41Hz -10dB bass point, 101dB maximum level, three tweeters, app EQ, stereo pairing and Auracast multi-speaker linking. The catch: It has no water resistance, aux input or USB playback, and its eight-hour claimed battery life is short for an outdoor portable.
Buy the Teufel Rockster Cross ($199.99) for a large speaker; the Harman Kardon Onyx Studio 9 ($189.99) suits a boombox speaker instead.
Battery life favors the Teufel Rockster Cross: rated for 16 hours against 8 hours for the Harman Kardon Onyx Studio 9.
Water resistance is not close: the Teufel Rockster Cross is rated at IPX5 (water jets), well ahead of the Harman Kardon Onyx Studio 9 at no water resistance.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Teufel Rockster Cross | Harman Kardon Onyx Studio 9 | |
|---|---|---|
| Price | $199.99 | $189.99 |
| Ranked | #23 of 82 in Large Size Portable Bluetooth Speakers | #15 of 76 in Boombox Size Portable Bluetooth Speakers |
| Aux Input | Yes | No |
| Bass Extension (-10dB) | 51Hz | 41Hz |
| Battery Life | 16 hours (Manufacturer specified) | 8 hours (Manufacturer specified) |
| IP Rating | IPX5 | None |
| Power Input | DC barrel jack | AC Power Cable (2-Prong) |
| TWS | Yes | Yes |
| Weight | 5.3 lbs (2.4 kg) | 9.3 lbs (4.2 kg) |
| App | No | Yes (Harman Kardon One app) |
| Bluetooth Codecs | SBC, aptX | SBC |
| Built-in Microphone | Yes | - |
| EQ | No | Yes (App EQ) |
| Party Mode | No | Yes (Auracast) |
| Power Bank | Yes (USB-A) | - |
| Stereo | Partially | Yes |
| Omnidirectional | No | No |
| Bluetooth Version | 5.0 | 5.3 |
| Dimensions | 15” x 6.3” x 5.1” (380 x 160 x 130 mm) | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) |
| Drivers | 5” woofer, 2x textile dome tweeters + 2x passive radiators | 120mm woofer + 3x 20mm tweeters |
| Frequency Response | 50Hz - 20kHz (Manufacturer specified) | - |
| Amplifier Power | 30W | 50W RMS |
| Digital Aux Input | No | No |
| Strap | Yes (detachable shoulder strap) | No |
| Maximum SPL | - | 101dB (measured by Alan Ross Reviews) |
| USB Playback | - | No |
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Prices on this page were last checked September 26, 2026 at 11:14 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Speakers In Full
Teufel Rockster Cross: $199.99 Amazon eBay
Newer model: the Teufel Rockster Cross 2, rated 4.2/5.
Pros: Pretty neutral frequency response. More vocal/midrange-focused than the JBL Xtreme 4, thanks to a larger mid/bass driver - better suited to rock and jazz. Nicer upper-bass detail than the JBL Xtreme 4. Punchy, well-controlled bass that suits rock music, unlike the Soundcore Boom 2 Plus’s overboosted, uncontrolled bass even at stock tuning. Clear, detailed audio with good vocal presence and solid Bluetooth codec support even a couple years after release. Measured bass extension of 51Hz (-10dB).
Cons: Outdoor mode can sound somewhat harsh due to the 4kHz peak. Not as deep or full-sounding in the bass as the JBL Xtreme 4.
Full Teufel Rockster Cross review and specifications →
| Amplifier Power | 30W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | 51Hz |
| Battery Life | 16 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC, aptX |
| Bluetooth Version | 5.0 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 15” x 6.3” x 5.1” (380 x 160 x 130 mm) |
| Drivers | 5” woofer, 2x textile dome tweeters + 2x passive radiators |
| EQ | No |
| Frequency Response | 50Hz - 20kHz (Manufacturer specified) |
| IP Rating | IPX5 |
| Omnidirectional | No |
| Party Mode | No |
| Power Bank | Yes (USB-A) |
| Power Input | DC barrel jack |
| Stereo | Partially |
| Strap | Yes (detachable shoulder strap) |
| TWS | Yes |
| Weight | 5.3 lbs (2.4 kg) |
- Links
- Reviews, Comparisons and Sound Samples
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Harman Kardon Onyx Studio 9: $189.99 Amazon eBay
Older models: the Harman Kardon Onyx Studio 8 (rated 4.1/5), the Harman Kardon Onyx Studio 7 (rated 4.1/5), the Harman Kardon Onyx Studio 6 (rated 4.1/5), the Harman Kardon Onyx Studio 5 (rated 3.9/5) and the Harman Kardon Onyx Studio 4 (rated 3.3/5).
Pros: An elegant 4.2kg living-room portable with a measured 41Hz -10dB bass point, 101dB maximum level, three tweeters, app EQ, stereo pairing and Auracast multi-speaker linking. Reviews praise its balanced, smooth presentation and non-fatiguing treble, making it a more music-focused choice than most party speakers. Measured bass extension of 41Hz (-10dB).
Cons: It has no water resistance, aux input or USB playback, and its eight-hour claimed battery life is short for an outdoor portable. Bass is less deep than some earlier Onyx Studio models, while the slightly recessed mids and rolled-off top end mean it is not the most open or detailed option; it still charges from an AC power cable rather than USB-C.
Full Harman Kardon Onyx Studio 9 review and specifications →
| Amplifier Power | 50W RMS |
|---|---|
| App | Yes (Harman Kardon One app) |
| Aux Input | No |
| Bass Extension (-10dB) | 41Hz |
| Battery Life | 8 hours (Manufacturer specified) |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.3 |
| Digital Aux Input | No |
| Dimensions | 11.4” x 11.3” x 5.1” (289.2 x 287.5 x 130 mm) |
| Drivers | 120mm woofer + 3x 20mm tweeters |
| EQ | Yes (App EQ) |
| IP Rating | None |
| Maximum SPL | 101dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Auracast) |
| Power Input | AC Power Cable (2-Prong) |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| USB Playback | No |
| Weight | 9.3 lbs (4.2 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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