Short answer: the Bose Soundlink Flex. It ranks #34 of 136 medium speakers by sound quality at $84.99; the Ultimate Ears Megaboom 4 ranks #132 and costs $200, so there is little reason to consider the other one.
What the Bose Soundlink Flex offers: IP67 rated; rugged enough to survive drops from several feet and floats. Around 12 hours of battery at moderate volume. Watch for: Not stereo. Warm sounding with overly boosted bass which drowns out midrange detail
What the Ultimate Ears Megaboom 4 offers: IP67 rated, floats, and finally uses USB-C charging. 20 hour battery life. ‘PartyUp’ feature syncs multiple UE speakers together. Watch for: A lot of distortion at higher volumes. Rolled off treble. Not very loud. They really screwed this up
Buy the Bose Soundlink Flex. It ranks higher for sound quality than the Ultimate Ears Megaboom 4 and costs less, which settles it without a real tradeoff to make.
The Ultimate Ears Megaboom 4 is not a sound-quality pick. It sits near the bottom of the 136 medium speakers; there are better options higher up.
Battery life favors the Ultimate Ears Megaboom 4: rated for 20 hours against 12 hours for the Bose Soundlink Flex.
Specifications Side By Side
| Bose Soundlink Flex | Ultimate Ears Megaboom 4 | |
|---|---|---|
| Price | $84.99 | $200 |
| Ranked | #34 of 136 in Medium Size Portable Bluetooth Speakers | #132 of 136 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 | - |
| Max Volume | 96dB | 91dB |
| 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 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 |
Related Speaker Comparisons
A few more comparisons worth a look in the same class:
- Bose Soundlink Flex 2nd gen vs Bose Soundlink Mini
- Bose Soundlink Flex 2nd gen vs Sony SRS-XB20
- Bose Soundlink Flex 2nd gen vs Ultimate Ears Boom 3
- B&O Beosound A1 vs Bose Soundlink Flex
- Bose Soundlink Flex vs Harman Kardon Esquire 2
Prices on this page were last checked August 27, 2026 at 10:09 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: $84.99 Amazon eBay
Pros: IP67 rated; rugged enough to survive drops from several feet and floats. Around 12 hours of battery at moderate volume.
Cons: Not stereo. Warm sounding with overly boosted bass which drowns out midrange detail
Full Bose Soundlink Flex review and specifications →
| App | Yes |
|---|---|
| Bass Extension (-10dB) | 56Hz |
| Battery Life | 12 hours (Manufacturer specified) |
| 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 |
| Max Volume | 96dB |
| Omnidirectional | No |
| Party Mode | Yes (Bose Party mode) |
| Power Input | USB-C |
| Stereo | No |
| 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 →
- Alan Ross Reviews: Bose Soundlink Flex Review! vs JBL Flip 6 and JBL Charge 5. Travel heaven?? 🤞 More from alanrossreviews →
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen vs Flex
- 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: Bose Soundlink Flex vs Soundcore Boost vs Bogasing M4 - cheap or Bose?
- 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 →
- Oluv Patreon: Soundcore Motion 300 = Bose Soundlink Flex = Earfun UBoom L?
- Alan Ross Reviews: Bose Soundlink Flex or JBL Flip 6 (eq adjusted) or Denon Envaya - best speaker for travel!
- Alan Ross Reviews: Bose Soundlink Flex or Beosound A1 (1st gen) - ultimate compact speaker 😇
- Alan Ross Reviews: Bose Soundlink Flex or JBL Flip 6 (eq adjusted) or Denon Envaya - best speaker for travel!
- Jay’s Straight Up Reviews & More: Tribit Stormbox Flow vs Soundcore Motion 300 (LDAC) 😵 Budget Bose Soundlink Flex “Inspired” Speakers
- Patricio Benadon: Bose SoundLink Flex vs. Mini 2 SE. Music audio quality sound test. Listen 4 different genres!
- Patricio Benadon: Bose SoundLink Flex vs. Mini 2 SE. Music audio quality sound test. Listen 4 different genres!
- Danny Pops: BEST Bose Speaker?? Bose Soundlink Flex vs micro, Color II, and revolve + More from DannyPops →
- Alan Ross Reviews: Bose Soundlink Flex vs Minirig MK3 and Marshall Emberton - best bluetooth speaker?
- Joy & Oluv’Sone: JBL, Bose, B&O, Sonos, Earfun, SoundCore… which portable speaker sounds best?
- Alan Ross - The Anti Shill!: Small speaker, mighty sound, The Flex gen 2 shatters physics!
- Reddit Search for Bose Soundlink Flex Review
- 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 Teufel Rockster XS
- Bose Soundlink Flex vs Soundcore Motion 100
- Bose Soundlink Flex vs Tribit Stormbox Pro
- Bose Soundlink Flex vs Soundcore Boom 3i
- Bose Soundlink Flex vs Xiaomi Sound Outdoor
- See all 77 comparisons
Ultimate Ears Megaboom 4: $200 Amazon eBay
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 →
| App | Yes |
|---|---|
| Battery Life | 20 hours (Manufacturer specified) |
| 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 |
| Max Volume | 91dB |
| Omnidirectional | Yes |
| Party Mode | Yes (PartyUp up to 50 speakers) |
| Power Input | USB-C |
| Stereo | No |
| 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? 😧
- Reddit Search for Ultimate Ears Megaboom 4 Review
- Head-to-Head Comparisons
- Ultimate Ears Megaboom 4 vs Doss Soundbox
- Ultimate Ears Megaboom 4 vs Doss Soundbox Pro
- Ultimate Ears Megaboom 4 vs Zealot S61
- Ultimate Ears Megaboom 4 vs Skullcandy Terrain/Terrain XT/Terrain XL
- Ultimate Ears Megaboom 4 vs Beats Pill+
- Ultimate Ears Megaboom 4 vs Ultimate Ears Roll 2
- Ultimate Ears Megaboom 4 vs Harman Kardon Esquire 2
- Ultimate Ears Megaboom 4 vs Tribit Stormbox Mini
- See all 75 comparisons