Short answer: the Tronsmart Mirtune C3. It ranks #102 of 182 medium speakers by sound quality, rated 3.1/5, at $29.99; the Ultimate Ears Boom 4 ranks #114, rated 2.9/5, and costs $114.99, which makes this an easy call rather than a real tradeoff.
Why pick the Tronsmart Mirtune C3: A small, light waterproof speaker at a budget price, with Auracast multi speaker sync, stereo pairing, USB-C audio input and app EQ. The catch: In GiT’s three way blind test it came behind the Creative Muvo Go and Xiaomi Sound Outdoor, sounding good only on sparse tracks, and listeners in AudioPro Reviews’ comparison found the JBL Flip 6 fuller with more bass.
What the Ultimate Ears Boom 4 does well: A tough waterproof speaker that floats, with USB-C charging, app EQ and pairing with other UE speakers. It plays in stereo from a single unit, unlike the Tronsmart Mirtune C3. The tradeoff: Not much improvement over the old ones.
Buy the Tronsmart Mirtune C3. It is rated higher for sound quality than the Ultimate Ears Boom 4 and costs less, so only choose the other one for a particular feature it does better.
Want more options? Browse the full Portable Bluetooth rankings.
Prices on this page were last checked November 14, 2026 at 6:17 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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Specifications Side By Side
| Tronsmart Mirtune C3 | Ultimate Ears Boom 4 | |
|---|---|---|
| Price | $29.99 | $114.99 |
| Ranked | #102 of 182 in Medium Size Portable Bluetooth Speakers | #114 of 182 in Medium Size Portable Bluetooth Speakers |
| Aux Input | No | No |
| Amplifier Power | 30W | - |
| App | Yes (Tronsmart) | Yes |
| Battery Capacity | 14.8Wh (7.4V, 2000mAh) | - |
| Battery Life | 12 hours at 50% volume (Manufacturer specified) | 15 hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC |
| Bluetooth Version | 6.0 | 5.1 |
| Charging Time | 2 hours | - |
| Digital Aux Input | Yes (USB-C) | No |
| Dimensions | 7.1”H x 2.8”W x 2.8”D (180 x 70 x 72 mm) | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) |
| Drivers | 1x racetrack woofer + 1x tweeter | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators |
| EQ | Yes (app) | Yes (via app) |
| Frequency Response | 55Hz - 20kHz (Manufacturer specified) | - |
| IP Rating | IPX7 | IP67 |
| Omnidirectional | No | No |
| Party Mode | Yes (Auracast) | - |
| Power Input | USB-C | USB-C |
| Stereo | No | Yes |
| Strap | Yes (lanyard) | Yes (built-in loop) |
| TWS | Yes | Yes |
| Weight | 1.2 lbs (0.53 kg) | 1.4 lbs (620 g) |
| Built-in Microphone | - | No |
| Power Bank | - | No |
| Maximum SPL | - | 85dBC (Manufacturer specified) |
Where the Ratings Come From
- Tronsmart Mirtune C3: reviews by THBOX, GiT and AudioPro.
- Ultimate Ears Boom 4: reviews by Smart Home Sounds and Cameron Dougherty Tech.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
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