Bose Soundlink Flex 2nd gen vs Sony ULT Field 3

Last updated: September 21, 2026

Short answer: the Bose Soundlink Flex 2nd gen. It ranks #35 of 142 medium speakers against the ULT Field 3’s #60, and costs $21 less at $159 versus $138.

Bose Soundlink Flex 2nd gen vs Sony ULT Field 3

The Flex’s sound is a known quantity. Its pros note it sounds pretty much identical to the first-generation Flex, a speaker that already earned a strong reputation; reviewer Alan Ross Reviews and Joy & Oluv’Sone both have direct sound-test comparisons between the two generations if you want to hear the difference for yourself. The tradeoffs are a warm tuning with overly boosted bass that can drown out midrange detail, and no stereo pairing.

The ULT Field 3 has a tuning conflict that undercuts its extra features. Its cons note it sounds a bit hollow and boosted in the treble, and that the custom EQ and ULT bass-boost button cannot run together: turning on ULT disables the EQ, and bass is very weak with ULT off. It also lost to the JBL Charge 6 in a direct side-by-side comparison despite being the larger speaker.

Where the ULT Field 3 pulls ahead is battery and connectivity. It is rated for 24 hours against the Flex’s 12, and adds stereo pairing, Party Connect for up to 100 speakers, and a USB-C power bank function that the Flex lacks. The Flex counters with its own party mode for linking multiple Bose speakers.

Buy the Bose Soundlink Flex 2nd gen for better sound quality at a lower price, especially if you don’t need all-day battery life.

Buy the Sony ULT Field 3 if you need double the runtime and multi-speaker Party Connect, and can live with its bass-versus-EQ tradeoff.

Want more options? Browse the full Portable Bluetooth rankings.

Buy the Bose Soundlink Flex 2nd gen at Amazon ($159.00) →Buy the Sony ULT Field 3 at Amazon ($138.00) →

Specifications Side By Side

Bose Soundlink Flex 2nd gen Sony ULT Field 3
Price$159.00$138.00
Ranked#35 of 142 in Medium Size Portable Bluetooth Speakers#60 of 142 in Medium Size Portable Bluetooth Speakers
AppYesYes
Battery Life12 hours (Manufacturer specified)24 hours (Manufacturer specified)
Built-in MicrophoneYesYes
EQYes (3 band)Yes (App + ULT button)
IP RatingIP67IP67
Party ModeYes (Bose Party mode)Yes (Party Connect up to 100 speakers)
Power InputUSB-CUSB-C
StereoNoYes
OmnidirectionalNoNo
TWSYesYes
Weight1.3 lbs (586 g)2.6 lbs (1.2 kg)
Bluetooth Version5.35.2
Dimensions7.9" x 3.5" x 2" (201 x 90 x 52 mm)10.1" x 4.4" x 3.1" (256 x 113 x 79 mm)
Aux InputNoNo
Drivers60mm full-range driver with passive radiators1x 20mm tweeter + 1x 86mm x 46mm woofer
Bluetooth CodecsSBC, AAC, aptX AdaptiveSBC, AAC, LDAC
Digital Aux InputNoNo
Power Bank-Yes (USB-C, 5V/1.5A)
Amplifier Power-27W
Buy the Bose Soundlink Flex 2nd gen at Amazon ($159.00) →Buy the Sony ULT Field 3 at Amazon ($138.00) →

How Bose Soundlink Flex 2nd gen compares with other leading options:

Prices on this page were last checked September 22, 2026 at 5:11 AM 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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The Two Speakers In Full

Bose Soundlink Flex 2nd gen ranking card

Pros: A very portable 586g, IP67-rated speaker with a clear, well-balanced midrange that keeps voices and instruments intelligible. The second generation adds a Bose app with 3-band EQ, better-placed controls and stereo pairing with another Bose Soundlink Flex 2nd gen. It supports AAC and aptX Adaptive in addition to SBC, making it a stronger wireless option than most small rivals.

Cons: One Flex remains mono and cannot deliver genuine low-bass rumble; RTINGS also found the elevated treble can turn hi-hats and other high-frequency detail piercing. The claimed battery life is only 12 hours, and some owners report accelerated standby drain after firmware updates. It is expensive for its size, so the added app and codec support, not a transformational sound upgrade over the original, are the main reasons to choose it.

Full Bose Soundlink Flex 2nd gen review and specifications →

AppYes
Aux InputNo
Battery Life12 hours (Manufacturer specified)
Bluetooth CodecsSBC, AAC, aptX Adaptive
Bluetooth Version5.3
Built-in MicrophoneYes
Digital Aux InputNo
Dimensions7.9" x 3.5" x 2" (201 x 90 x 52 mm)
Drivers60mm full-range driver with passive radiators
EQYes (3 band)
IP RatingIP67
OmnidirectionalNo
Party ModeYes (Bose Party mode)
Power InputUSB-C
StereoNo
TWSYes
Weight1.3 lbs (586 g)
Check current price at Amazon ($159.00) →Search eBay for Bose Soundlink Flex 2nd gen →

Sony ULT Field 3: $138.00 Amazon eBay

Sony ULT Field 3 ranking card

Pros: IP67 rated, dustproof and water resistant. 24 hour battery life. App with 10-band EQ. Party Connect with up to 100 speakers. USB-C in/out for charging your phone.

Cons: Sounds a bit hollow, a bit boosted in the treble. Custom EQ and the ULT bass-boost button can’t be used together - turning on ULT disables the EQ. Bass is very weak with ULT off. Lost to the JBL Charge 6 in a side-by-side comparison despite being the larger speaker.

Full Sony ULT Field 3 review and specifications →

Amplifier Power27W
AppYes
Aux InputNo
Battery Life24 hours (Manufacturer specified)
Bluetooth CodecsSBC, AAC, LDAC
Bluetooth Version5.2
Built-in MicrophoneYes
Digital Aux InputNo
Dimensions10.1" x 4.4" x 3.1" (256 x 113 x 79 mm)
Drivers1x 20mm tweeter + 1x 86mm x 46mm woofer
EQYes (App + ULT button)
IP RatingIP67
OmnidirectionalNo
Party ModeYes (Party Connect up to 100 speakers)
Power BankYes (USB-C, 5V/1.5A)
Power InputUSB-C
StereoYes
TWSYes
Weight2.6 lbs (1.2 kg)
Check current price at Amazon ($138.00) →Search eBay for Sony ULT Field 3 →