Short answer: the Bose Soundlink Flex 2nd gen. It ranks #37 of 175 medium speakers by sound quality (rated 3.8/5) at $99.99 and is still sold new; the Ultimate Ears Wonderboom ranks #112 (rated 2.9/5) and is discontinued, so it is only an option used. The Ultimate Ears Wonderboom’s replacement, the Ultimate Ears Wonderboom 4, is rated 2.9/5 at $74.50.
The Bose Soundlink Flex 2nd gen is the better-sounding option. A very portable 1.3 lbs (586 g), IP67-rated speaker with a clear, well-balanced midrange that keeps voices and instruments intelligible. It links with other speakers (Bose Party mode), which the Ultimate Ears Wonderboom cannot. It has an adjustable EQ, which the Ultimate Ears Wonderboom lacks. It charges over USB-C rather than Micro USB. The tradeoff: 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 Ultimate Ears Wonderboom is the lighter option. IP67 rated and floats. At 0.9 lbs (425 g) it weighs noticeably less than the Bose Soundlink Flex 2nd gen at 1.3 lbs (586 g). Watch for: Not stereo, barely any bass, recessed treble.
Buy the Bose Soundlink Flex 2nd gen. It is rated higher for sound quality and still sold new, while the Ultimate Ears Wonderboom is discontinued.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Bose Soundlink Flex 2nd gen | Ultimate Ears Wonderboom | |
|---|---|---|
| Price | $99.99 | $79 Discontinued |
| Ranked | #37 of 175 in Medium Size Portable Bluetooth Speakers | #112 of 175 in Medium Size Portable Bluetooth Speakers |
| App | Yes | No |
| Battery Life | 12 hours (Manufacturer specified) | 10 hours (Manufacturer specified) |
| Built-in Microphone | Yes | No |
| EQ | Yes (3 band) | No |
| IP Rating | IP67 | IPX7 |
| Party Mode | Yes (Bose Party mode) | No |
| Power Input | USB-C | Micro USB |
| Stereo | No | No |
| Omnidirectional | No | Yes |
| TWS | Yes | Yes |
| Weight | 1.3 lbs (586 g) | 0.9 lbs (425 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.3 | - |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) | 4” x 3.7” (102 x 93.5 mm) |
| Aux Input | No | No |
| Drivers | 60mm full-range driver with passive radiators | 2x 1.6” active drivers + 2x 1.8” x 2.6” passive radiators |
| Bluetooth Codecs | SBC, AAC, aptX Adaptive | SBC (inferred; additional codecs unverified) |
| Digital Aux Input | No | No |
| Strap | Yes (built-in loop) | Yes (built-in loop) |
Related Speaker Comparisons
How Bose Soundlink Flex 2nd gen compares with other leading options:
- Bose Soundlink Flex 2nd gen vs EarFun Uboom L
- Bose Soundlink Flex 2nd gen vs Soundcore Motion 300
- Bose Soundlink Flex 2nd gen vs Soundcore Motion+
- Bose Soundlink Flex 2nd gen vs Soundcore Boost “upgraded” 2021
- Bose Soundlink Flex 2nd gen vs Minirig 4
Prices on this page were last checked October 12, 2026 at 4:13 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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The Two Speakers In Full
Bose Soundlink Flex 2nd gen: $99.99 Amazon $99.99 eBay
Older model: the Bose Soundlink Flex (ranked lower, rated 3.8/5). See every Bose SoundLink Flex, Micro, Max and Plus generation.
Same family: the Bose SoundLink Max (larger model, rated 4.3/5), the Bose Soundlink Micro 2 (larger model, rated 3.6/5) and the Bose SoundLink Plus (larger model, rated 4.2/5).
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 →
| Released | Sep 2024 (2 years ago) |
|---|---|
| App | Yes |
| Aux Input | No |
| Battery Life | 12 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC, AAC, aptX Adaptive |
| Bluetooth Version | 5.3 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) |
| Drivers | 60mm full-range driver with passive radiators |
| EQ | Yes (3 band) |
| IP Rating | IP67 |
| Omnidirectional | No |
| Party Mode | Yes (Bose Party mode) |
| Power Input | USB-C |
| Stereo | No |
| Strap | Yes (built-in loop) |
| TWS | Yes |
| Weight | 1.3 lbs (586 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen vs Flex More from Oluv’Sone →
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen & Soundcore Motion 300 sound test
- Oluv Patreon: Bose Soundlink Flex 2nd gen - sound demo
- Alan Ross: Hall of Fame classic vs latest Bose tech! More from alanrossreviews →
- Alan Ross - The Anti Shill!: Small speaker, mighty sound, The Flex gen 2 shatters physics!
- Alan Ross - The Anti Shill!: DBSONO X-Blast F37 vs Bose Soundlink Flex 2 - They all want to be me 😊
- Mateusz Cholewa: JBL Charge Essential 3 SE vs BOSE SoundLink FLEX 2 More from Mateusz Cholewa →
- CEONTHEMAKING: Bose Soundlink Flex 2nd Gen VS Marshall Emberton III - What’s NEW?? More from CEONTHEMAKING →
- Tô Thái Trí Hùng: Unbox & Sound Test - Bose Soundlink Flex 2
- Musou1: JBL flip 7 vs KEF muo vs Bose flex 2
- Head-to-Head Comparisons
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- Bose Soundlink Flex 2nd gen vs Cleer Audio Scene
- Bose Soundlink Flex 2nd gen vs Soundcore Boom 3i
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- See all 146 comparisons
Ultimate Ears Wonderboom: $79 Discontinued eBay
Newer model: the Ultimate Ears Wonderboom 4, ranked higher, rated 2.9/5, released Jun 2024. See every Ultimate Ears Wonderboom, Boom and Megaboom generation.
Pros: IP67 rated and floats. Compact, light, and simple to use.
Cons: Not stereo, barely any bass, recessed treble. Dip at 9kHz. Low mid bass distortion. Not technically a 360 speaker, only front and rear. Discontinued.
Full Ultimate Ears Wonderboom review and specifications →
| Released | Nov 2017 (8 years ago) |
|---|---|
| App | No |
| Aux Input | No |
| Battery Life | 10 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 4” x 3.7” (102 x 93.5 mm) |
| Drivers | 2x 1.6” active drivers + 2x 1.8” x 2.6” passive radiators |
| EQ | No |
| IP Rating | IPX7 |
| Omnidirectional | Yes |
| Party Mode | No |
| Power Input | Micro USB |
| Stereo | No |
| Strap | Yes (built-in loop) |
| TWS | Yes |
| Weight | 0.9 lbs (425 g) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Ultimate Ears Wonderboom vs Ultimate Ears Wonderboom 2
- Ultimate Ears Wonderboom vs Ultimate Ears Boom 4
- Ultimate Ears Wonderboom vs Ultimate Ears Wonderboom 3
- Ultimate Ears Wonderboom vs Ultimate Ears Boom 3
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- Ultimate Ears Wonderboom vs Ultimate Ears Wonderboom 4
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- See all 74 comparisons