Short answer: the Bose Soundlink Flex. It ranks #38 of 175 medium speakers by sound quality (rated 3.8/5) at $159 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 is the better-sounding choice. IP67 rated; rugged enough to survive drops from several feet and floats. It links with other speakers (Bose Party mode), which the Ultimate Ears Wonderboom cannot. It charges over USB-C rather than Micro USB. The tradeoff: Warm sounding with overly boosted bass which drowns out midrange detail.
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 at 1.3 lbs (589 g). The catch: Not stereo, barely any bass, recessed treble.
Buy the Bose Soundlink Flex. It is rated higher for sound quality, and the Ultimate Ears Wonderboom is discontinued, so it is only available used.
Looking for alternatives? See the complete Portable Bluetooth rankings.
Specifications Side By Side
| Bose Soundlink Flex | Ultimate Ears Wonderboom | |
|---|---|---|
| Price | $159.00 | $79 Discontinued |
| Ranked | #38 of 175 in Medium Size Portable Bluetooth Speakers | #112 of 175 in Medium Size Portable Bluetooth Speakers |
| App | Yes | No |
| Bass Extension (-10dB) | 56Hz | - |
| Battery Life | 12 hours (Manufacturer specified) | 10 hours (Manufacturer specified) |
| Built-in Microphone | Yes | No |
| EQ | No | No |
| IP Rating | IP67 | IPX7 |
| Bluetooth Latency | 33ms | - |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) | - |
| 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 (589 g) | 0.9 lbs (425 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 4.2 | - |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) | 4” x 3.7” (102 x 93.5 mm) |
| Drivers | 1x 60mm full-range driver + 2x passive radiators | 2x 1.6” active drivers + 2x 1.8” x 2.6” passive radiators |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC | SBC (inferred; additional codecs unverified) |
| Aux Input | No | No |
| Strap | Yes (built-in loop) | Yes (built-in loop) |
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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: $159.00 Amazon $159.00 eBay
Newer model: the Bose Soundlink Flex 2nd gen, ranked higher, rated 3.8/5, released Sep 2024. It adds adjustable EQ, AAC and aptX Adaptive. See every Bose SoundLink Flex, Micro, Max and Plus generation.
Pros: IP67 rated; rugged enough to survive drops from several feet and floats. Around 12 hours of battery at moderate volume. Measured bass extension of 56Hz (-10dB).
Cons: Not stereo. Warm sounding with overly boosted bass which drowns out midrange detail
Full Bose Soundlink Flex review and specifications →
| Released | Oct 2021 (5 years ago) |
|---|---|
| App | Yes |
| Aux Input | No |
| Bass Extension (-10dB) | 56Hz |
| Battery Life | 12 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Latency | 33ms |
| Bluetooth Version | 4.2 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) |
| Drivers | 1x 60mm full-range driver + 2x passive radiators |
| EQ | No |
| IP Rating | IP67 |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) |
| 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 (589 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen vs Flex More from Oluv’Sone →
- Joy & Oluv’Sone: JBL, Bose, B&O, Sonos, Earfun, SoundCore… which portable speaker sounds best?
- Oluv Patreon: Bose Soundlink Plus & Flex compared
- Oluv Patreon: Soundcore Motion 300 = Bose Soundlink Flex = Earfun UBoom L?
- Alan Ross Reviews: Bose Soundlink Flex or Beosound A1 (1st gen) - ultimate compact speaker 😇 More from alanrossreviews →
- Alan Ross Reviews: Bose Soundlink Flex vs Minirig MK3 and Marshall Emberton - best bluetooth speaker?
- Alan Ross - The Anti Shill!: Small speaker, mighty sound, The Flex gen 2 shatters physics!
- Alan Ross Reviews: Travel Speakers! Soundcore Motion 300 or Bose Flex or Tribit Stormbow Flow
- Alan Ross Reviews: Bose Soundlink Flex Review! vs JBL Flip 6 and JBL Charge 5. Travel heaven?? 🤞
- Alan Ross Reviews: Bose Soundlink Flex vs Soundcore Boost vs Bogasing M4 - cheap or Bose?
- Alan Ross Reviews: Bose Soundlink Flex or JBL Flip 6 (eq adjusted) or Denon Envaya - best speaker for travel!
- Alan Ross Reviews: 1 million views! Best Budget Tws? Tozo Pa1 Review and sound test
- Alan Ross Reviews: Beats Pill vs Harman Luna vs Bose Flex vs Soundcore Motion Plus
- Alan Ross Reviews: Tribit Xsound Mega vs the world! (JBL Charge 5, Bose Flex, Sony XB33, LG PL7) 👍
- Alan Ross Reviews: Tribit Stormbox Flow has deeper bass than the Bose Flex but………..
- Jay’s Straight Up Reviews & More: Tribit Stormbox Flow vs Soundcore Motion 300 (LDAC) 😵 Budget Bose Soundlink Flex "Inspired" Speakers More from JaysStraightUpReviews →
- Danny Pops: BEST Bose Speaker?? Bose Soundlink Flex vs micro, Color II, and revolve + More from DannyPops →
- Danny Pops: BEST Bose Speaker? Bose is getting lazy.
- Patricio Benadon: Bose SoundLink Flex vs. Mini 2 SE. Music audio quality sound test. Listen 4 different genres!
- Head-to-Head Comparisons
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- See all 142 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
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