Short answer: the Teufel Rockster Go 2. It ranks #93 of 179 medium speakers by sound quality, rated 3.2/5, at $99.99; the Ultimate Ears Boom 4 ranks #113, rated 2.9/5, and costs $114.99, so there is little reason to consider the other one.
The Teufel Rockster Go 2 is the better-sounding option. A light, rugged waterproof speaker with very long battery life in eco mode, stereo pairing and a tripod mount. It supports AAC Bluetooth, which the Ultimate Ears Boom 4 lacks. Watch for: There is no companion app or 3.5 mm input.
The case for the Ultimate Ears Boom 4: A tough waterproof speaker that floats, with USB-C charging, app EQ and pairing with other UE speakers. The catch: Not much improvement over the old ones.
Buy the Teufel Rockster Go 2. It is rated higher for sound quality than the Ultimate Ears Boom 4 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
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Specifications Side By Side
| Teufel Rockster Go 2 | Ultimate Ears Boom 4 | |
|---|---|---|
| Price | $99.99 | $114.99 |
| Ranked | #93 of 179 in Medium Size Portable Bluetooth Speakers | #113 of 179 in Medium Size Portable Bluetooth Speakers |
| Aux Input | No | No |
| Battery Life | 15 hours, 28 with Eco Mode (Manufacturer specified) | 15 hours (Manufacturer specified) |
| IP Rating | IP67 | IP67 |
| Weight | 1.6 lbs (735 g) | 1.4 lbs (620 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC, AAC | SBC |
| Dimensions | 8.3” x 4.3” x 2.4” (211 x 109 x 61 mm) | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) |
| Drivers | 2x 50mm wide-band drivers + 1x 64mm passive radiator | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators |
| TWS | Yes | Yes |
| Party Mode | Yes (Party Link, up to 100 speakers) | - |
| Built-in Microphone | No | No |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Digital Aux Input | Yes (USB-C sound card) | No |
| App | Yes (Teufel Go) | Yes |
| EQ | Yes | Yes (via app) |
| Power Input | USB-C | USB-C |
| Power Bank | No | No |
| USB Playback | No | - |
| Amplifier Power | 8W | - |
| Frequency Response | 60Hz - 20kHz (Manufacturer specified) | - |
| Charging Time | 2.5 hours (Manufacturer specified) | - |
| Strap | Yes (detachable strap) | Yes (built-in loop) |
| Bluetooth Version | - | 5.1 |
| Maximum SPL | - | 85dBC (Manufacturer specified) |
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