Products
Bose SoundLink Flex
Ultimate Ears WONDERBOOM 4
Tested using Methodology v0.8
Updated Oct 31, 2024 02:49 PM
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Walmart.com
Tested using Methodology v0.8
Updated Aug 26, 2025 01:00 PM
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Amazon.com
Bluetooth
Yes
Wi-Fi
No
Speakerphone
Yes
Voice Assistant
Yes
Battery Powered
Yes
Bluetooth
Yes
Wi-Fi
No
Speakerphone
No
Voice Assistant
No
Battery Powered
Yes
Our Verdict
Bose SoundLink Flex
Ultimate Ears WONDERBOOM 4
The Bose SoundLink Flex and the Ultimate Ears WONDERBOOM 4 are both portable speakers with different strengths. Because the Ultimate Ears has a 360-degree design, it has a much better soundstage performance: your audio sounds more or less the same from every angle. On the other hand, the Bose downmixes your audio to mono, and its drivers face forward. The Ultimate Ears also has a much lower Bluetooth latency than the Bose, so it's better suited to watching videos, but different apps and devices compensate for latency in different ways. On the other hand, only the Bose is compatible with your device's Google Assistant or Siri voice assistant, as the Ultimate Ears doesn't have a microphone. If battery life is a priority, the Ultimate Ears is your best bet, as it lasts six hours longer than the Bose.
Variants
- SoundLink Flex (Black)
- SoundLink Flex (Carmine Red)
- SoundLink Flex (Chilled Lilac)
- SoundLink Flex (Cypress Green)
- SoundLink Flex (Stone Blue)
- SoundLink Flex (White Smoke)
- WONDERBOOM 4 (Active Black)
- WONDERBOOM 4 (Cobalt Blue)
- WONDERBOOM 4 (Hyper Pink)
- WONDERBOOM 4 (Joyous Bright)
- WONDERBOOM 4 (Sand Beige)
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Black
SoundLink Flex
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Amazon.com
Active Black
WONDERBOOM 4
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Amazon.com
Carmine Red
SoundLink Flex
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Amazon.com
Cobalt Blue
WONDERBOOM 4
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Amazon.com
Chilled Lilac
SoundLink Flex
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Amazon.com
Hyper Pink
WONDERBOOM 4
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Amazon.com
Cypress Green
SoundLink Flex
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Amazon.com
Joyous Bright
WONDERBOOM 4
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Amazon.com
Stone Blue
SoundLink Flex
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Walmart.com
Sand Beige
WONDERBOOM 4
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BestBuy.com
White Smoke
SoundLink Flex
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Amazon.com
Main Differences for
Music
Music
Threshold
Music
6.3
6.8
Soundstage
5.5
9.0
Frequency Response Accuracy
6.9
6.3
Dynamics
6.4
7.3
Full Comparison
Design
Style
Style Photo
RGB Lights
No
No
Portability
9.2
9.3
Dimensions Photo
Volume
57 in³ (942 cm³)
58 in³ (944 cm³)
Weight
1.3 lbs (0.6 kg)
0.9 lbs (0.4 kg)
Power Source
Battery & USB
Battery & USB
One-Hand Carry
Yes
Yes
Build Quality
8.7
9.0
Build Quality Photo
Material Quality
Good
Great
Water Resistance
Submersible (IPx7)
Submersible (IPx7)
Dust Resistance
Dust-Proof (IP6x)
Dust-Proof (IP6x)
Impact Resistance
Yes (IK rating unspecified)
Yes (IK rating unspecified)
Floats In Water
Yes
Yes
Controls
8.4
6.6
Controls Photo
Controls Photo 2
Ease Of Use
Okay
Great
Feedback
Decent
Good
Music Play/Pause
Yes (Physical)
Yes (Physical)
Call Answer/End
Yes (Physical)
No
Volume Up/Down
Yes (Physical)
Yes (Physical)
Track Next/Previous
Yes (Physical)
Forward Only (Physical)
Microphone On/Off
Yes (Physical)
No
Additional Controls
Yes
Yes
In The Box
In The Box Photo
Sound
Frequency Response Accuracy
6.9
6.3
Frequency Response Graph
Slope
0.22
0.31
Std. Err.
2.85 dB
2.29 dB
Low-Frequency Extension
60.8 Hz
89.8 Hz
High-Frequency Extension
15.6 kHz
16.0 kHz
Raw Frequency Response
Raw Frequency Response Graph
Binaural Recording @ 1m
Binaural Recording @ 2m
Soundstage
5.5
9.0
Directivity Graph
Directivity Index
4.59 dB
1.79 dB
Stereo
No (mono)
Yes
Dynamics
6.4
7.3
Dynamic Range Compression
SPL @ Max Volume
87.5 dB SPL
≈ 86.7 dB SPL
DRC @ Max Volume
3.02 dB
1.00 dB
Active Features
Battery
6.7
8.9
Battery Life
7.2 hrs
13.1 hrs
Charge Time
2.7 hrs
2.5 hrs
Power Saving
Yes
Yes
Charging Port
USB-C
USB-C
Battery Powered
Yes
Yes
Voice Assistant
5.7
0.0
Alexa
No
No
Google Assistant
Yes (Requires Smartphone)
No
Speakerphone
Yes
No
Siri
Yes (Requires Smartphone)
No
Voice Assistant
Yes
No
Voice Activation
No
No
Microphone Mute
No
No
Far-Field Performance
Excellent
No Microphone
Ambient Noise Performance
Excellent
No Microphone
App
6.6
3.2
App Picture
App Name
Bose Connect
No App
iOS
Yes
No
Android
Yes
No
EQ
No
No
Stereo Pair Mode
Yes
Yes
Party Mode
Yes
Yes
Multi-Room
No
No
Connectivity
Wired
Aux Input
No
No
USB Audio
No
No
Other Ports
No
No
Bluetooth
8.0
8.9
Bluetooth
Yes
Yes
Bluetooth Version
4.2
5.2
Bluetooth iOS Latency
236 ms
66 ms
Bluetooth Android Latency
109 ms
82 ms
Bluetooth Range
255.9 ft (78.0 m)
334.6 ft (102.0 m)
Multi-Device Pairing
2 Devices
2 Devices
Wi-Fi
0.0
0.0
Wi-Fi Version
No Wi-Fi
No Wi-Fi
Wi-Fi Frequency Band
No Wi-Fi
No Wi-Fi
Wi-Fi
No
No
Apple AirPlay
No
No
AirPlay Latency
N/A
N/A
Google Chromecast
No
No
Chromecast Latency
N/A
N/A
Check Price
Black
SoundLink Flex
SEARCH
Amazon.com
Active Black
WONDERBOOM 4
SEE PRICE
Amazon.com
Carmine Red
SoundLink Flex
SEARCH
Amazon.com
Cobalt Blue
WONDERBOOM 4
SEE PRICE
Amazon.com
Chilled Lilac
SoundLink Flex
SEARCH
Amazon.com
Hyper Pink
WONDERBOOM 4
SEE PRICE
Amazon.com
Cypress Green
SoundLink Flex
SEARCH
Amazon.com
Joyous Bright
WONDERBOOM 4
SEE PRICE
Amazon.com
Stone Blue
SoundLink Flex
SEE PRICE
Walmart.com
Sand Beige
WONDERBOOM 4
SEE PRICE
BestBuy.com
White Smoke
SoundLink Flex
SEARCH
Amazon.com
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Bose SoundLink Flex
Ultimate Ears WONDERBOOM 4
Comments
Bose SoundLink Flex vs Ultimate Ears WONDERBOOM 4: Main Discussion
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