If you were to ask me what my favorite new portable Bluetooth speaker of 2025 is so far, I’d have to say Sony’s ULT Field 5 speaker. When it launched back in April, I called it one of the best-sounding Bluetooth speakers I’ve tested in its size class. However, it cost $330, which is pretty pricey, though I suspected we’d see it discounted in due time. Well, that time is now, as the speaker is on sale for $250 or $80 off its list price for Memorial Day. 

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In fact, a few other Sony Bluetooth speakers are on sale for good prices, including the new ULT Field 3 ($150 or $50 off) and the compact ULT Field 1 ($88 or $42 off). They’re all good portable speakers, but the ULT Field 5 has the best sound of the bunch and is arguably the best overall. 

ULT is short for ultimate or, as Sony says, “The ultimate step into the evolution of its portable audio products.” Power represents “dynamic sound pressure and deep bass.” Sound translates to “as if you were in the front row at a concert.”

In the past, I thought Sony’s Bluetooth speakers were decent enough but not great. However, with the ULT series, Sony’s significantly improved the sound quality of its Bluetooth speakers.

I also like the new designs of the ULT Field 3 and ULT Field 5, which can stand vertically or lay horizontally. Both speakers are fully waterproof, dust-proof, and rust-proof, with an IP67 certification. Both include a new removable shoulder strap, which I ended up using more with the heftier ULT Field 5 than the lighter ULT Field 3. The ULT Field 5 weights 7.27 pounds while the ULT Field 3 weighs 2.65 pounds — a big difference. (Read my hands-on first take review of both speakers).

The ULT Field 3 delivers more bass and volume than you’d expect, given its relatively compact size (and it offers better clarity and bass performance than its predecessor, the SRS-XE300). But the ULT Field 5’s soundstage is noticeably wider and the speaker plays louder with noticeably fuller, richer sound. It also has built-in party lighting with a USB-C charge in-out port so the speaker can be used as a power bank to charge your devices. Battery life is rated at up to 25 hours at moderate volume levels or 10 hours with the party lighting activated. 

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Don’t expect real stereo separation from either the ULT Field 5 or ULT Field 3. To get true stereo separation, you’ll need to link two of them together, creating a stereo pair (Sony has made it easier to link its ULT speakers in both Party Connect mode and stereo mode). Of course, not everybody can afford one of these speakers, let alone two, but it helps that they’re now on sale. 

ULT Field 5 key specs    

• Weight: 7.27 pounds
• Drivers: 1 woofer, 2 passive bass radiators, 2 tweeters
• EQ: ULT1 Mode (deep frequencies), ULT2 Mode (powerful sound), 10-Band EQ, Sound Field Optimization
• App control: Sound Connect app (iOS and Android)
• Price: $330 (on sale now for $250)
• Colors: Available in black and off white
• Predecessor: SRS-XG300
• IP67 waterproof, dust-proof, rust-proof and shock-resistant
• Party lighting 
• Removable shoulder strap
• Up to 25 hours of battery life (10 hours with lighting on)
• Speakerphone (built-in microphone)
• In-out USB-C charge, so the speaker can be used as a power bank
• 3.5mm audio input
• Link multiple speakers with Party Connect or stereo pair