Different classes, so treat this as a step-up-or-not question rather than a head-to-head. The Harman Kardon Go + Play 3 ranks #3 of 113 boombox speakers by sound quality at $385; the Sony ULT Field 5 ranks #59 of 120 large speakers by sound quality at $348.
The Go + Play 3 is the better sounding speaker. It has the deepest bass of any boombox in its class, reaching about 35Hz, with a warm and more natural tuning than the Go + Play 2. It is a boombox at 10.4 lbs (4.7 kg) with a 5 inch subwoofer, two midrange drivers and two tweeters.
The ULT Field 5 is built for outdoors. It is IP67 against the Go + Play 3’s lack of any water rating, lasts a claimed 25 hours against 8, and weighs 7.3 lbs (3.3 kg). It supports LDAC, has a 10-band app EQ, Party Connect and a USB-C power bank. Reviews find it energetic and bass focused, with subdued upper mids and highs.
Volume: the Go + Play 3 measures about 103dB, a little over half as loud as the loudest boomboxes. Both have an aux input, a built-in microphone and stereo pairing.
Choose the Go + Play 3 for sound indoors or on a patio with power nearby, and the ULT Field 5 for beach, pool or campsite use.
Buy the Harman Kardon Go + Play 3 at $385 if you want a boombox speaker. Buy the Sony ULT Field 5 at $348 if you want a large speaker instead.
There is a real gap in water resistance: the Sony ULT Field 5 at IP67 (brief submersion) against the Harman Kardon Go + Play 3, which has no water resistance.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
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Specifications Side By Side
| Harman Kardon Go + Play 3 | Sony ULT Field 5 | |
|---|---|---|
| Price | $385 | $348.00 |
| Ranked | #3 of 113 in Boombox Size Portable Bluetooth Speakers | #59 of 120 in Large Size Portable Bluetooth Speakers |
| App | Yes (Harman Kardon One app) | Yes |
| Aux Latency | 112ms | - |
| Bass Extension (-10dB) | 35Hz | - |
| Battery Life | 8 hours (Manufacturer specified) | 25 hours (Manufacturer specified) |
| Built-in Microphone | Yes | Yes |
| EQ | Yes (App EQ) | Yes (App + ULT button) |
| IP Rating | None | IP67 |
| Bluetooth Latency | 120ms | - |
| Maximum SPL | 103dB (measured by Alan Ross Reviews) | - |
| Power Input | AC Power brick | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Weight | 10.4 lbs (4.7 kg) | 7.3 lbs (3.3 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC, AAC | SBC, AAC, LDAC |
| Power Bank | Yes | Yes (USB-C) |
| Party Mode | No | Yes (Party Connect up to 100 speakers) |
| USB Playback | No | - |
| Bluetooth Version | 5.2 | 5.3 |
| Amplifier Power | 160W RMS | 27W |
| Dimensions | 17.3” x 9.4” x 7.6” (439 x 240 x 192 mm) | 12.6” x 5.7” x 4.9” (320 x 144 x 125 mm) |
| Aux Input | Yes | Yes |
| Drivers | 1x 130mm (5”) subwoofer + 2x 70mm midrange drivers + 2x 20mm tweeters | 2x 46mm tweeters + 1x 79mm x 107mm woofer |
| Digital Aux Input | No | No |
| Strap | No | Yes (detachable shoulder strap) |
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