Short answer: the Bose Soundlink Flex. It ranks #38 of 175 medium speakers by sound quality, rated 3.8/5, at $159. The Ultimate Ears Boom 3 ranks #114, rated 2.9/5, at $134.99, $24.01 cheaper, which does not close the gap in sound quality.
The Bose Soundlink Flex is the better-sounding, deeper-bass choice. IP67 rated; rugged enough to survive drops from several feet and floats. Its bass reaches about 56Hz before falling 10dB, against 91Hz for the Ultimate Ears Boom 3. It charges over USB-C rather than Micro USB. The catch: Warm sounding with overly boosted bass which drowns out midrange detail.
The case for the Ultimate Ears Boom 3: Rich and warm bass without muddying mix, crisp highs, excellent 15-hour battery life, stable Bluetooth connectivity, IP67 rated and floats, rugged fabric shell, can pair up to 150 speakers via PartyUp. It has an adjustable EQ, which the Bose Soundlink Flex lacks. It plays in stereo from a single unit, unlike the Bose Soundlink Flex. The catch: Not stereo, barely any bass, recessed treble.
Buy the Bose Soundlink Flex. It is rated higher for sound quality, and saving $24.01 with the Ultimate Ears Boom 3 does not make up for the sound-quality gap.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Bose Soundlink Flex | Ultimate Ears Boom 3 | |
|---|---|---|
| Price | $159.00 | $134.99 |
| Ranked | #38 of 175 in Medium Size Portable Bluetooth Speakers | #114 of 175 in Medium Size Portable Bluetooth Speakers |
| App | Yes | Yes (Ultimate Ears BOOM & MEGABOOM app) |
| Bass Extension (-10dB) | 56Hz | 91Hz |
| Battery Life | 12 hours (Manufacturer specified) | 15 hours (Manufacturer specified) |
| Built-in Microphone | Yes | No |
| EQ | No | Yes (via app) |
| IP Rating | IP67 | IP67 |
| Bluetooth Latency | 33ms | - |
| Maximum SPL | 96dB (measured by Alan Ross Reviews) | 87dB (Manufacturer specified) |
| Party Mode | Yes (Bose Party mode) | Yes (PartyUp up to 50 speakers) |
| Power Input | USB-C | Micro USB |
| Stereo | No | Yes |
| Omnidirectional | No | Yes |
| TWS | Yes | Yes |
| Weight | 1.3 lbs (589 g) | 1.3 lbs (608 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 4.2 | 4.2 |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) | 7.2” x 2.9” (184 x 73 mm) |
| Drivers | 1x 60mm full-range driver + 2x passive radiators | 2x 2” active drivers + 2x 2” x 4” passive radiators |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC | SBC |
| Aux Input | No | No |
| Strap | Yes (built-in loop) | Yes (built-in loop) |
Related Speaker Comparisons
More worthwhile head-to-heads for Bose Soundlink Flex:
- Bose Soundlink Flex vs EarFun Uboom L
- Soundcore Motion 300 vs Bose Soundlink Flex
- Soundcore Motion+ vs Bose Soundlink Flex
- Soundcore Boost “upgraded” 2021 vs Bose Soundlink Flex
- Bose Soundlink Flex 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.
As an eBay Partner, we may be compensated if you make a purchase.
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
- Bose Soundlink Flex vs Bose Soundlink Flex 2nd gen
- Bose Soundlink Flex vs JBL Charge Essential 2
- Bose Soundlink Flex vs Tribit Xsound Plus 2
- Bose Soundlink Flex vs Huawei Sound Joy
- Bose Soundlink Flex vs Teufel Rockster XS
- Bose Soundlink Flex vs Cleer Audio Scene
- Bose Soundlink Flex vs JBL Charge Essential 3 SE
- Bose Soundlink Flex vs EarFun Uboom Slim
- See all 142 comparisons
Ultimate Ears Boom 3: $134.99 Amazon $134.99 eBay
Newer model: the Ultimate Ears Boom 4, ranked higher, rated 2.9/5, released Jun 2024. See every Ultimate Ears Wonderboom, Boom and Megaboom generation.
Pros: Rich and warm bass without muddying mix, crisp highs, excellent 15-hour battery life, stable Bluetooth connectivity, IP67 rated and floats, rugged fabric shell, can pair up to 150 speakers via PartyUp. Measured bass extension of 91Hz (-10dB).
Cons: Not stereo, barely any bass, recessed treble. You can tell from the micro USB that they are just feeding you the same crap hardware over and over, this is inexcusable for a product released in 2021. Lots of mentions of failing batteries on amazon. Not technically a 360 speaker, only front and rear.
Full Ultimate Ears Boom 3 review and specifications →
| Released | Sep 2018 (8 years ago) |
|---|---|
| App | Yes (Ultimate Ears BOOM & MEGABOOM app) |
| Aux Input | No |
| Bass Extension (-10dB) | 91Hz |
| Battery Life | 15 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 4.2 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 7.2” x 2.9” (184 x 73 mm) |
| Drivers | 2x 2” active drivers + 2x 2” x 4” passive radiators |
| EQ | Yes (via app) |
| IP Rating | IP67 |
| Maximum SPL | 87dB (Manufacturer specified) |
| Omnidirectional | Yes |
| Party Mode | Yes (PartyUp up to 50 speakers) |
| Power Input | Micro USB |
| Stereo | Yes |
| Strap | Yes (built-in loop) |
| TWS | Yes |
| Weight | 1.3 lbs (608 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Ultimate Ears Boom 3 vs Ultimate Ears Boom 4
- Ultimate Ears Boom 3 vs Klipsch Groove
- Ultimate Ears Boom 3 vs Ultimate Ears Wonderboom
- Ultimate Ears Boom 3 vs Ultimate Ears Wonderboom 2
- Ultimate Ears Boom 3 vs Sony SRS-XE300
- Ultimate Ears Boom 3 vs Ultimate Ears Wonderboom 3
- Ultimate Ears Boom 3 vs Tribit Stormbox
- Ultimate Ears Boom 3 vs Ultimate Ears Wonderboom 4
- See all 99 comparisons