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  1. Table of Contents
  2. Top
  3. Main Differences
  4. Design
    1. Pictures
    2. Style
    3. Portability
    4. Build Quality
    5. Controls
    6. In The Box
  5. Sound
    1. Frequency Response Accuracy
    2. Raw Frequency Response
    3. Soundstage
    4. Dynamics
  6. Active Features
    1. Battery
    2. Voice Assistant
    3. App
  7. Connectivity
    1. Wired
    2. Bluetooth
    3. Wi-Fi
  8. Comments

Bose SoundLink Flex vs Ultimate Ears BOOM 4

Side-by-Side Comparison

Products

Bose SoundLink Flex
Ultimate Ears BOOM 4

Tested using Methodology v0.8

Updated Oct 31, 2024 02:49 PM

SEE PRICE
Walmart.com

Tested using Methodology v0.8

Updated Nov 20, 2024 03:25 PM

SEE PRICE
Amazon.com
Bose SoundLink Flex Picture
Ultimate Ears BOOM 4 Picture
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

Variants

  • SoundLink Flex (Black)
  • SoundLink Flex (Carmine Red)
  • SoundLink Flex (Chilled Lilac)
  • SoundLink Flex (Cypress Green)
  • SoundLink Flex (Stone Blue)
  • SoundLink Flex (White Smoke)
  • BOOM 4 (Active Black)
  • BOOM 4 (Cobalt Blue)
  • BOOM 4 (Enchanting Lilac)
  • BOOM 4 (Raspberry Red)

Review

See Bose SoundLink Flex Review
See Ultimate Ears BOOM 4 Review
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Our Verdict

Bose SoundLink Flex

Ultimate Ears BOOM 4

The Bose SoundLink Flex and the Ultimate Ears BOOM 4 are portable speakers that feature some key differences that can help you make your buying decision. The Bose features a more balanced sound profile that can more accurately reproduce the details of music and movies. It also has better controls and a built-in mic that works with the voice assistant on your iOS or Android device. That said, the Ultimate Ears is undoubtedly the better pick for outdoor use, thanks to its excellent directivity and much longer battery life. It can also get similarly loud without compressing as much.

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Check Price

Black
SoundLink Flex
Searching
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Active Black
BOOM 4
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Carmine Red
SoundLink Flex
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Cobalt Blue
BOOM 4
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Chilled Lilac
SoundLink Flex
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Enchanting Lilac
BOOM 4
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Cypress Green
SoundLink Flex
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Raspberry Red
BOOM 4
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Stone Blue
SoundLink Flex
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White Smoke
SoundLink Flex
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Main Differences for
Music

Threshold 

0.10

Music 

6.3
6.7

Frequency Response Accuracy 
 

6.9
5.7

Soundstage 
 

5.5
9.1

EQ 
 

No
Graphic + Presets

Dynamics 
 

6.4
7.1

Full Comparison

Design

Style  

Style Photo  

Bose SoundLink Flex Style Photo
Ultimate Ears BOOM 4 Style Photo

RGB Lights  

No
No
Show text

Portability 
 

9.2
9.2

Dimensions Photo  

Bose SoundLink Flex Dimensions Photo
Ultimate Ears BOOM 4 Dimensions Photo

Volume 
 

57 in³ (942 cm³)
58 in³ (953 cm³)

Weight 
 

1.3 lbs (0.6 kg)
1.4 lbs (0.6 kg)

Power Source 
 

Battery & USB
Battery & USB

One-Hand Carry 
 

Yes
Yes
Show text

Build Quality 
 

8.7
9.0

Build Quality Photo  

Bose SoundLink Flex Build Quality Photo
Ultimate Ears BOOM 4 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
Show text

Controls 
 

8.4
5.8

Controls Photo  

Bose SoundLink Flex Controls Photo
Ultimate Ears BOOM 4 Controls Photo

Controls Photo 2  

Bose SoundLink Flex Controls Photo 2
Ultimate Ears BOOM 4 Controls Photo 2

Ease Of Use 
 

Okay
Good

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)
No

Microphone On/Off 
 

Yes (Physical)
No

Additional Controls 
 

Yes
No
Show text

In The Box 
 

In The Box Photo  

Bose SoundLink Flex In The Box Photo
Ultimate Ears BOOM 4 In The Box Photo
Show text
Sound

Frequency Response Accuracy 
 

6.9
5.7

Frequency Response Graph  

See details on graph tool
See details on graph tool

Slope 
 

0.22
-1.26

Std. Err. 
 

2.85 dB
4.07 dB

Low-Frequency Extension 
 

60.8 Hz
93.8 Hz

High-Frequency Extension 
 

15.6 kHz
17.0 kHz
Show text

Raw Frequency Response 
 

Raw Frequency Response Graph  

See details on graph tool
See details on graph tool

Binaural Recording @ 1m 
 

Binaural Recording @ 2m 
 

Soundstage 
 

5.5
9.1

Directivity Graph  

See details on graph tool
See details on graph tool

Directivity Index 
 

4.59 dB
1.72 dB

Stereo 
 

No (mono)
Yes
Show text

Dynamics 
 

6.4
7.1

Dynamic Range Compression  

See details on graph tool
See details on graph tool

SPL @ Max Volume 
 

87.5 dB SPL
87.0 dB SPL

DRC @ Max Volume 
 

3.02 dB
1.55 dB
Show text
Active Features

Battery 
 

6.7
8.8

Battery Life 
 

7.2 hrs
12.1 hrs

Charge Time 
 

2.7 hrs
2.6 hrs

Power Saving 
 

Yes
Yes

Charging Port 
 

USB-C
USB-C

Battery Powered 
 

Yes
Yes
Show text

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 Microphone

Far-Field Performance 
 

Excellent
No Microphone

Ambient Noise Performance 
 

Excellent
No Microphone
Show text

App 
 

6.6
7.9

App Picture  

Bose SoundLink Flex App Picture
Ultimate Ears BOOM 4 App Picture

App Name 
 

Bose Connect
Ultimate Ears

iOS 
 

Yes
Yes

Android 
 

Yes
Yes

EQ 
 

No
Graphic + Presets

Stereo Pair Mode 
 

Yes
Yes

Party Mode 
 

Yes
Yes

Multi-Room 
 

No
No
Show text
Connectivity

Wired 
 

Aux Input 
 

No
No

USB Audio 
 

No
No

Other Ports 
 

No
No
Show text

Bluetooth 
 

8.0
8.1

Bluetooth 
 

Yes
Yes

Bluetooth Version 
 

4.2
Unspecified

Bluetooth iOS Latency 
 

236 ms
51 ms

Bluetooth Android Latency 
 

109 ms
112 ms

Bluetooth Range 
 

255.9 ft (78.0 m)
341.2 ft (104.0 m)

Multi-Device Pairing 
 

2 Devices
No
Show text

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
Searching
Finding store
Active Black
BOOM 4
Searching
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Carmine Red
SoundLink Flex
Searching
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Cobalt Blue
BOOM 4
Searching
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Chilled Lilac
SoundLink Flex
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Enchanting Lilac
BOOM 4
Searching
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Cypress Green
SoundLink Flex
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Raspberry Red
BOOM 4
Searching
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Stone Blue
SoundLink Flex
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White Smoke
SoundLink Flex
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Back to Top

Bose SoundLink Flex

Ultimate Ears BOOM 4

Comments

  1. Comparison
 • Posted 6 months ago

Bose SoundLink Flex vs Ultimate Ears BOOM 4: Main Discussion

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