Bose Soundlink Flex 2nd gen vs Ultimate Ears Megaboom 4

Last updated: October 12, 2026

Short answer: the SoundLink Flex 2nd gen is the better fit for a compact warm-sounding speaker, while the Megaboom 4 offers a larger rugged format and longer stated runtime. Bose is 37 of 175; UE is 170 of 175. Neither is a neutral, high-output choice.

Bose Soundlink Flex 2nd gen vs Ultimate Ears Megaboom 4

The Flex is a mono design whose boosted bass can hide midrange detail, and it loses charge while sitting unused. The Megaboom 4 floats, carries an IP67 rating, uses USB-C, and supports PartyUp, but it has rolled-off treble, limited loudness, and substantial distortion as volume rises.

Buy the Bose SoundLink Flex 2nd gen if compact size and a richer low-end presentation outweigh its mono output and standby drain.

Buy the Ultimate Ears Megaboom 4 if you need the larger floating enclosure, USB-C charging, and PartyUp speaker linking.

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.

Still deciding? The full Portable Bluetooth rankings cover every ranked option.

Check Bose Soundlink Flex 2nd gen price at Amazon ($99.99) →Check Ultimate Ears Megaboom 4 price at Amazon ($200) →

Specifications Side By Side

Bose Soundlink Flex 2nd gen Ultimate Ears Megaboom 4
Price$99.99$200
Ranked#37 of 175 in Medium Size Portable Bluetooth Speakers#170 of 175 in Medium Size Portable Bluetooth Speakers
AppYesYes
Battery Life12 hours (Manufacturer specified)20 hours (Manufacturer specified)
Built-in MicrophoneYesNo
EQYes (3 band)Yes (via app)
IP RatingIP67IP67
Party ModeYes (Bose Party mode)Yes (PartyUp up to 50 speakers)
Power InputUSB-CUSB-C
StereoNoNo
OmnidirectionalNoYes
TWSYesYes
Weight1.3 lbs (586 g)2.4 lbs (1.1 kg)
BluetoothYesYes
Bluetooth Version5.35.1
Dimensions7.9” 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 InputNoNo
Drivers60mm full-range driver with passive radiators2x 50x50mm full-range + 2x 55x86mm passive radiators
Bluetooth CodecsSBC, AAC, aptX AdaptiveSBC
Digital Aux InputNoNo
StrapYes (built-in loop)Yes (built-in loop)
Maximum SPL-91dB (Manufacturer specified)
Check Bose Soundlink Flex 2nd gen price at Amazon ($99.99) →Check Ultimate Ears Megaboom 4 price at Amazon ($200) →

More worthwhile head-to-heads for Bose Soundlink Flex 2nd gen:

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 2nd gen ranking card

Older model: the Bose Soundlink Flex (ranked lower, rated 3.8/5). See every Bose SoundLink Flex, Micro, Max and Plus generation.

Same family: the Bose SoundLink Max (larger model, rated 4.3/5), the Bose Soundlink Micro 2 (larger model, rated 3.6/5) and the Bose SoundLink Plus (larger model, rated 4.2/5).

Pros: A very portable 586g, IP67-rated speaker with a clear, well-balanced midrange that keeps voices and instruments intelligible. The second generation adds a Bose app with 3-band EQ, better-placed controls and stereo pairing with another Bose Soundlink Flex 2nd gen. It supports AAC and aptX Adaptive in addition to SBC, making it a stronger wireless option than most small rivals.

Cons: One Flex remains mono and cannot deliver genuine low-bass rumble; RTINGS also found the elevated treble can turn hi-hats and other high-frequency detail piercing. The claimed battery life is only 12 hours, and some owners report accelerated standby drain after firmware updates. It is expensive for its size, so the added app and codec support, not a transformational sound upgrade over the original, are the main reasons to choose it.

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Full Bose Soundlink Flex 2nd gen review and specifications →

ReleasedSep 2024 (2 years ago)
AppYes
Aux InputNo
Battery Life12 hours (Manufacturer specified)
BluetoothYes
Bluetooth CodecsSBC, AAC, aptX Adaptive
Bluetooth Version5.3
Built-in MicrophoneYes
Digital Aux InputNo
Dimensions7.9” x 3.5” x 2” (201 x 90 x 52 mm)
Drivers60mm full-range driver with passive radiators
EQYes (3 band)
IP RatingIP67
OmnidirectionalNo
Party ModeYes (Bose Party mode)
Power InputUSB-C
StereoNo
StrapYes (built-in loop)
TWSYes
Weight1.3 lbs (586 g)
Check current price at Amazon ($99.99) →Search eBay for Bose Soundlink Flex 2nd gen →

Ultimate Ears Megaboom 4: $200 Amazon $200 eBay

Ultimate Ears Megaboom 4 ranking card

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 →

ReleasedJun 2024 (2 years ago)
AppYes
Aux InputNo
Battery Life20 hours (Manufacturer specified)
BluetoothYes
Bluetooth CodecsSBC
Bluetooth Version5.1
Built-in MicrophoneNo
Digital Aux InputNo
Dimensions3.4” x 3.4” x 8.9” (87 x 87 x 225 mm)
Drivers2x 50x50mm full-range + 2x 55x86mm passive radiators
EQYes (via app)
IP RatingIP67
Maximum SPL91dB (Manufacturer specified)
OmnidirectionalYes
Party ModeYes (PartyUp up to 50 speakers)
Power InputUSB-C
StereoNo
StrapYes (built-in loop)
TWSYes
Weight2.4 lbs (1.1 kg)
Check current price at Amazon ($200) →Search eBay for Ultimate Ears Megaboom 4 →