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 Megaboom 4 ranks #170, rated 2.1/5, and costs $200, so there is little reason to consider the other one.
The Bose Soundlink Flex is the better-sounding, lighter choice. IP67 rated; rugged enough to survive drops from several feet and floats. At 1.3 lbs (589 g) it weighs much less than the Ultimate Ears Megaboom 4 at 2.4 lbs (1.1 kg). The catch: Warm sounding with overly boosted bass which drowns out midrange detail.
The Ultimate Ears Megaboom 4 is the longer-running pick. IP67 rated, floats, and finally uses USB-C charging. It is rated for 20 hours of battery against 12 for the Bose Soundlink Flex. It has an adjustable EQ, which the Bose Soundlink Flex lacks. Watch for: A lot of distortion at higher volumes.
Buy the Bose Soundlink Flex. It is rated higher for sound quality than the Ultimate Ears Megaboom 4 and costs less, so only choose the other one for a particular feature it does better.
Want more options? Browse the full Portable Bluetooth rankings.
Specifications Side By Side
| Bose Soundlink Flex | Ultimate Ears Megaboom 4 | |
|---|---|---|
| Price | $159.00 | $200 |
| Ranked | #38 of 175 in Medium Size Portable Bluetooth Speakers | #170 of 175 in Medium Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Bass Extension (-10dB) | 56Hz | - |
| Battery Life | 12 hours (Manufacturer specified) | 20 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) | 91dB (Manufacturer specified) |
| Party Mode | Yes (Bose Party mode) | Yes (PartyUp up to 50 speakers) |
| Power Input | USB-C | USB-C |
| Stereo | No | No |
| Omnidirectional | No | Yes |
| TWS | Yes | Yes |
| Weight | 1.3 lbs (589 g) | 2.4 lbs (1.1 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 4.2 | 5.1 |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) | 3.4” x 3.4” x 8.9” (87 x 87 x 225 mm) |
| Drivers | 1x 60mm full-range driver + 2x passive radiators | 2x 50x50mm full-range + 2x 55x86mm 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
How Bose Soundlink Flex compares with other leading options:
- 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.
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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
- 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
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- See all 142 comparisons
Ultimate Ears Megaboom 4: $200 Amazon $200 eBay
Older model: the Ultimate Ears Megaboom 3 (ranked higher, rated 3/5). See every Ultimate Ears Wonderboom, Boom and Megaboom generation.
Same family: the Ultimate Ears Wonderboom 4 (smaller model, ranked higher, rated 2.9/5) and the Ultimate Ears Boom 4 (smaller model, ranked higher, rated 2.9/5).
Pros: IP67 rated, floats, and finally uses USB-C charging. 20 hour battery life. ‘PartyUp’ feature syncs multiple UE speakers together.
Cons: A lot of distortion at higher volumes. Rolled off treble. Not very loud. They really screwed this up
Full Ultimate Ears Megaboom 4 review and specifications →
| Released | Jun 2024 (2 years ago) |
|---|---|
| App | Yes |
| Aux Input | No |
| Battery Life | 20 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.1 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 3.4” x 3.4” x 8.9” (87 x 87 x 225 mm) |
| Drivers | 2x 50x50mm full-range + 2x 55x86mm passive radiators |
| EQ | Yes (via app) |
| IP Rating | IP67 |
| Maximum SPL | 91dB (Manufacturer specified) |
| Omnidirectional | Yes |
| Party Mode | Yes (PartyUp up to 50 speakers) |
| Power Input | USB-C |
| Stereo | No |
| Strap | Yes (built-in loop) |
| TWS | Yes |
| Weight | 2.4 lbs (1.1 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Jay’s Straight Up Reviews & More: Ultimate Ears MegaBoom 4 vs Sony ULT Field 1 😧 $200 vs $128 Cylinder Bluetooth Speaker Matchup More from JaysStraightUpReviews →
- Jay’s Straight Up Reviews & More: Ultimate Ears MegaBoom 4 vs W-King D320 🔋Does Paying More Get You Less? 😧
- Smart Home Sounds: UE Everboom Review PLUS All-New Wonderboom 4, Boom 4 & Megaboom 4 More from Smart Home Sounds →
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