Short answer: the Tronsmart Mirtune C3. Both are rated 3.1/5 for sound quality (#102 and #99 of 182 medium speakers), and the Tronsmart Mirtune C3 costs $29.99 against $138 for the Sony ULT Field 1, with sound quality a draw, the lower price decides it.
Why pick the Sony ULT Field 1: A tough, waterproof small speaker that survives drops, with long real world battery life and stereo pairing. It supports AAC Bluetooth, which the Tronsmart Mirtune C3 lacks. Watch for: Upper midrange peak, rolled off treble.
The case for 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. Watch for: 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.
Buy the Tronsmart Mirtune C3. Both are rated the same for sound quality, and it costs $108.01 less than the Sony ULT Field 1.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
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
| Sony ULT Field 1 | Tronsmart Mirtune C3 | |
|---|---|---|
| Price | $138.00 | $29.99 |
| Ranked | #99 of 182 in Medium Size Portable Bluetooth Speakers | #102 of 182 in Medium Size Portable Bluetooth Speakers |
| App | Yes | Yes (Tronsmart) |
| Aux Input | No | No |
| Battery Life | 12 hours (Manufacturer specified) | 12 hours at 50% volume (Manufacturer specified) |
| Built-in Microphone | Yes | - |
| EQ | Yes | Yes (app) |
| IP Rating | IP67 | IPX7 |
| Party Mode | Yes (Party Connect up to 100 speakers) | Yes (Auracast) |
| Power Bank | No | - |
| Power Input | USB-C | USB-C |
| Stereo | No | No |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 1.4 lbs (650 g) | 1.2 lbs (0.53 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | AAC, SBC | SBC |
| Bluetooth Version | 5.3 | 6.0 |
| Dimensions | 8.1” x 3” x 3” (206 x 77 x 76 mm) | 7.1”H x 2.8”W x 2.8”D (180 x 70 x 72 mm) |
| Drivers | 83mm x 42mm woofer, 16mm tweeter + passive radiator | 1x racetrack woofer + 1x tweeter |
| Digital Aux Input | No | Yes (USB-C) |
| Strap | Yes (detachable strap) | Yes (lanyard) |
| Amplifier Power | - | 30W |
| Battery Capacity | - | 14.8Wh (7.4V, 2000mAh) |
| Charging Time | - | 2 hours |
| Frequency Response | - | 55Hz - 20kHz (Manufacturer specified) |
Where the Ratings Come From
- Sony ULT Field 1: reviews by Techder Audios, Jay’s Straight Up Reviews & More and Storytripper HD.
- Tronsmart Mirtune C3: reviews by THBOX, GiT and AudioPro.
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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