Short answer: the Bose Soundlink Flex 2nd gen. It ranks #33 of 136 medium speakers by sound quality at $159; the Ultimate Ears Megaboom 4 ranks #132 and costs $200, which makes this an easy call rather than a real tradeoff.
What the Bose Soundlink Flex 2nd gen offers: Pretty much identical sounding to the 1st gen Watch for: Not stereo. Warm sounding with overly boosted bass which drowns out midrange detail. Self drains the battery about 10% a week.
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 2nd gen. 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.
There is a real battery-life gap here: the Ultimate Ears Megaboom 4 is rated for 20 hours, the Bose Soundlink Flex 2nd gen only 12 hours.
Specifications Side By Side
| Bose Soundlink Flex 2nd gen | Ultimate Ears Megaboom 4 | |
|---|---|---|
| Price | $159.00 | $200 |
| Ranked | #33 of 136 in Medium Size Portable Bluetooth Speakers | #132 of 136 in Medium Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Battery Life | 12 hours (Manufacturer specified) | 20 hours (Manufacturer specified) |
| Built in Microphone | Yes | No |
| EQ | Yes (3 band) | Yes (via app) |
| IP Rating | IP67 | IP67 |
| 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 / 586 g | 2.4 lbs / 1.1 kg |
| Bluetooth Version | 5.3 | 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) |
| Aux Input | No | - |
| Drivers | 60mm full-range driver with passive radiators | 2x 50x50mm full-range + 2x 55x86mm passive radiators |
| Bluetooth Codecs | SBC, AAC, aptX Adaptive | - |
| Digital Aux Input | No | No |
| Max Volume | - | 91dB |
Related Speaker Comparisons
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- Harman Kardon Luna vs Bose Soundlink Flex
- Bose Soundlink Flex 2nd gen vs Harman Kardon Esquire 2
- Bose Soundlink Flex 2nd gen vs JBL Charge 6
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 2nd gen: $159.00 Amazon eBay
Pros: Pretty much identical sounding to the 1st gen
Cons: Not stereo. Warm sounding with overly boosted bass which drowns out midrange detail. Self drains the battery about 10% a week.
Full Bose Soundlink Flex 2nd gen review and specifications →
| App | Yes |
|---|---|
| Aux Input | No |
| Battery Life | 12 hours (Manufacturer specified) |
| 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 |
| 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 →
- Oluv Patreon: Bose Soundlink Flex 2nd gen - sound demo
- Tô Thái Trí Hùng: Unbox & Sound Test - Bose Soundlink Flex 2
- Joy & Oluv’Sone: Bose Soundlink Flex 2nd gen & Soundcore Motion 300 sound test
- Alan Ross: Hall of Fame classic vs latest Bose tech! More from alanrossreviews →
- CEONTHEMAKING: Bose Soundlink Flex 2nd Gen VS Marshall Emberton III - What’s NEW??
- Alan Ross - The Anti Shill!: Small speaker, mighty sound, The Flex gen 2 shatters physics!
- Reddit Search for Bose Soundlink Flex 2nd gen Review
- Head-to-Head Comparisons
- Bose Soundlink Flex 2nd gen vs Bose Soundlink Flex
- Bose Soundlink Flex 2nd gen vs Tribit Xsound Plus 2
- Bose Soundlink Flex 2nd gen vs JBL Charge Essential 2
- Bose Soundlink Flex 2nd gen vs Teufel Rockster XS
- Bose Soundlink Flex 2nd gen vs Soundcore Boom 3i
- Bose Soundlink Flex 2nd gen vs Soundcore Motion 100
- Bose Soundlink Flex 2nd gen vs JBL Charge 5
- Bose Soundlink Flex 2nd gen vs Tribit Stormbox Pro
- See all 82 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
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