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JBL Synchros S100 Review | 93 Data compared

Avg. price: ~£45
Form factor: in-ear
Connectivity: wired
Battery life: N/A hours
Active noise cancellation (ANC): no

JBL Synchros S100 review. Compare 93 technical specifications and user reviews to see how it ranks among headphones and if it is worth buying.

4.7

Poor

4.5

Poor

5.7

Good

2.8
Gaming
Score components:
35.0%
0.0
Audio latency
25.0%
0.0
Low-latency game mode
20.0%
10
Can be used as a headset
12.0%
7.0
Noise-canceling microphone
8.0%
0.0
Battery life
1.9
Travel
Score components:
28.0%
1.0
Active noise cancellation (ANC)
24.0%
0.0
Battery life
18.0%
9.0
Weight
16.0%
0.0
Multipoint support
14.0%
0.0
Ambient sound mode
4.4
Calls
Score components:
28.0%
7.0
Noise-canceling microphone
24.0%
10
Can be used as a headset
18.0%
0.0
Multipoint support
16.0%
0.0
Battery life
14.0%
0.0
Companion app
6.7
Workout
Score components:
28.0%
9.0
Weight
24.0%
9.0
Water resistance
20.0%
4.0
IP rating
16.0%
0.0
Battery life
12.0%
10
Can be used as a headset

Best prices in UK

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Verdict

The JBL Synchros S100 is an advanced in-ear headphone featuring ultra-light, die-cast aluminum construction and a precision-made 9mm driver that delivers a frequency response of 10Hz to 22kHz with a maximum SPL of 106dB. Its main characteristics include JBL PureBass performance for deep, powerful lows, angled ear tips for a stable fit, and a tangle-resistant flat cable available in configurations for both iOS and Android devices. Main pros include a premium build with metal accents, the inclusion of Comply foam tips for superior isolation, and a distortion-free audio experience even at high volumes. However, some cons include below-average passive noise isolation and a shallow insertion depth that may make it difficult for some users to achieve a perfect seal depending on their ear canal shape.

Technical Specifications of JBL Synchros S100

Overall score

4.7

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Popularity

What it is: An indicator based on the number of reviews received by the headphones.

When it matters: When you prefer headphones that have already been chosen and reviewed by many other users.

Sound

4.5

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Active noise cancellation (ANC)

What it is: Reduces background noise using active technology

When it matters: When blocking office, travel, or aircraft noise is a priority.

Importance: HIGH

Driver type

What it is: Type of speaker driver technology used

When it matters: When the underlying sound character and driver technology matter to you.

Importance: MEDIUM

dynamic

Driver size

What it is: Diameter of the speaker driver unit

When it matters: When you want extra hardware context behind how the headphones may handle bass weight, scale, or overall presentation.

Importance: MEDIUM

Number of drivers

What it is: Total number of speaker drivers per earcup

When it matters: When multi-driver designs are part of your buying criteria.

Importance: LOW

Lowest frequency

What it is: Lowest audio frequency the headphones can reproduce

When it matters: When deeper bass extension matters for your music or movie listening.

Importance: MEDIUM

Good value: <=10 Hz

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Calls & Controls

8.3

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Noise-canceling microphone

What it is: Built-in microphone reduces background noise during calls

When it matters: When you take calls in busy spaces and want your voice to stay clearer.

Importance: MEDIUM

?

Can be used as a headset

What it is: Shows whether the headphones can handle voice chat and calls in addition to normal audio playback.

When it matters: When one pair needs to cover music, calls, meetings, and gaming chat.

Importance: MEDIUM

Number of microphones

What it is: Total number of built-in microphones

When it matters: When call pickup quality and beamforming support matter to you.

Importance: LOW

Good value: >=2

Boom microphone

What it is: Includes detachable boom microphone for voice clarity

When it matters: When you need stronger voice clarity for gaming, streaming, or work calls.

Importance: LOW

Microphone SNR

What it is: Signal-to-noise ratio of the microphone

When it matters: When call clarity matters and you want your voice picked up more cleanly instead of buried in background hiss.

Importance: LOW

Good value: >80 dB

?

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Connectivity

6.2

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Connectivity

What it is: Available connection methods (wired, wireless, Bluetooth, etc.)

When it matters: When the headphones need to match how you listen across wired and wireless devices.

Importance: HIGH

Bluetooth version

What it is: Version of Bluetooth technology supported

When it matters: When wireless stability, efficiency, and feature support matter more than treating Bluetooth as a box-check spec.

Importance: MEDIUM

Good value: >=5.0

N/A

Maximum Bluetooth range

What it is: Maximum wireless operating distance from source device

When it matters: When you move around rooms and want fewer dropouts from your source device.

Importance: LOW

Good value: >=10 m

N/A

Audio latency

What it is: Delay between audio and video in wireless mode

When it matters: When you watch video or play games and need sound to stay in sync.

Importance: HIGH

Good value: <60 ms

N/A

Multipoint support

What it is: Supports simultaneous connections to multiple devices

When it matters: When you switch often between a phone and a laptop during the day.

Importance: MEDIUM

N/A

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Features

2.7

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Ambient sound mode

What it is: Allows external sounds to pass through for awareness

When it matters: When you need to stay aware of traffic, voices, or announcements.

Importance: MEDIUM

N/A

EQ support

What it is: Allows customization of sound profile via equalizer

When it matters: When the stock tuning is not enough and you want to shape bass, mids, or treble to match your taste.

Importance: MEDIUM

Companion app

What it is: Dedicated mobile app for customization and updates

When it matters: When software customization, updates, and extra controls matter.

Importance: MEDIUM

N/A

Adjustable ANC levels

What it is: Allows adjustment of noise cancellation intensity levels

When it matters: When you move between quiet rooms, offices, streets, and public transport and do not want one ANC setting for every situation.

Importance: LOW

Good value: >=4

N/A

Voice assistant support

What it is: Compatible with voice assistants like Siri, Alexa, or Google Assistant

When it matters: When hands-free control is part of your daily routine.

Importance: LOW

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Battery

1.0

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Battery life

What it is: Playback time on a single charge

When it matters: When you commute, travel, or work long shifts and do not want charging breaks to interrupt listening.

Importance: HIGH

Good value: >45 hours

N/A

Battery life with ANC

What it is: Playback time with active noise cancellation enabled

When it matters: When you plan to keep noise cancellation on for most of the day.

Importance: HIGH

Good value: >40 hours

N/A

Charging time

What it is: Time required for a full battery charge

When it matters: When you often need the headphones ready again after short breaks.

Importance: MEDIUM

Good value: <=2 hours

N/A

Quick charge

What it is: Provides quick playback time with short charging period

When it matters: When a short top-up needs to deliver useful playback before you leave.

Importance: MEDIUM

N/A

Battery capacity

What it is: Total energy storage of the internal battery

When it matters: When you are estimating how much battery headroom the design may have before relying only on the official runtime claim.

Importance: MEDIUM

Good value: >=720 mAh

N/A

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Design

7.5

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Brand name

What it is: The manufacturer or brand of the product.

When it matters: When you prefer a specific ecosystem, support network, or design philosophy.

Importance: MEDIUM

JBL

Form factor

What it is: Overall design type of the headphones (over-ear, on-ear, in-ear, etc.)

When it matters: When comfort, portability, and isolation depend on the overall headphone style.

Importance: HIGH

in-ear

Weight

What it is: Total weight of the headphones

When it matters: When long listening sessions make wearing comfort more important.

Importance: MEDIUM

Good value: <150 g

?

Acoustic design

What it is: Type of acoustic design (open-back, closed-back, semi-open)

When it matters: When you need the right balance of isolation, leakage, and soundstage.

Importance: HIGH

closed-back

Clamp force

What it is: Amount of clamping pressure applied to the head

When it matters: When comfort and fit security matter during long sessions.

Importance: MEDIUM

N/A

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JBL Synchros S100 vs the average headphone

Why is JBL Synchros S100 better than the average headphone?

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Direct 3.5 mm plug
JBL Synchros S100 includes a direct 3.5 mm plug, the average headphone does not. 38.8% of headphones have a 3.5 mm male connector.
What it is: Shows whether the headphones end in a built-in 3.5 mm male plug instead of relying on a separate detachable cable.
When it matters: When direct wired compatibility with older devices or adapters matters.
Importance: MEDIUM
JBL Synchros S100 includes a direct 3.5 mm plug, the average headphone does not. 38.8% of headphones have a 3.5 mm male connector.
8 Hz lower bass extension
JBL Synchros S100 has a lower lowest frequency than the average headphone (10 Hz vs 18 Hz). The average headphones reach a lowest frequency of 18 Hz.
What it is: Lowest audio frequency the headphones can reproduce
When it matters: When deeper bass extension matters for your music or movie listening.
Importance: MEDIUM
Good value: <=10 Hz
JBL Synchros S100 has a lower lowest frequency than the average headphone (10 Hz vs 18 Hz). The average headphones reach a lowest frequency of 18 Hz.10 Hz vs 18 Hz
On-device controls
JBL Synchros S100 includes on-device controls, the average headphone does not. 46.8% of headphones support on-device controls.
What it is: Physical controls available directly on headphones
When it matters: When you need playback, volume, or call controls to be easy to reach without pulling out your phone.
Importance: MEDIUM
JBL Synchros S100 includes on-device controls, the average headphone does not. 46.8% of headphones support on-device controls.
In-line controls
JBL Synchros S100 includes in-line controls, the average headphone does not. 36.4% of headphones support in-line controls.
What it is: Controls available on in-line remote of wired cable
When it matters: When your wired setup depends on cable-mounted buttons or call controls.
Importance: LOW
JBL Synchros S100 includes in-line controls, the average headphone does not. 36.4% of headphones support in-line controls.
4 dB/mW higher sensitivity
JBL Synchros S100 has a higher sensitivity than the average headphone (106 dB/mW vs 102 dB/mW). The average headphones have sensitivity of 102 dB/mW.
What it is: Sound pressure output level per unit of input power
When it matters: When you plan to use weaker sources like phones, handhelds, or entry-level dongles and still want enough volume.
Importance: MEDIUM
Good value: >=106 dB/mW
JBL Synchros S100 has a higher sensitivity than the average headphone (106 dB/mW vs 102 dB/mW). The average headphones have sensitivity of 102 dB/mW.106 dB/mW vs 102 dB/mW
Boom microphone included
JBL Synchros S100 includes a boom microphone, the average headphone does not. 15.6% of headphones have a boom microphone.
What it is: Includes detachable boom microphone for voice clarity
When it matters: When you need stronger voice clarity for gaming, streaming, or work calls.
Importance: LOW
JBL Synchros S100 includes a boom microphone, the average headphone does not. 15.6% of headphones have a boom microphone.
2,000 Hz higher treble extension
JBL Synchros S100 has a higher highest frequency than the average headphone (22,000 Hz vs 20,000 Hz). The average headphones reach a highest frequency of 20,000 Hz.
What it is: Highest audio frequency the headphones can reproduce
When it matters: When treble extension and overall frequency reach matter to you.
Importance: MEDIUM
Good value: >=24000 Hz
JBL Synchros S100 has a higher highest frequency than the average headphone (22,000 Hz vs 20,000 Hz). The average headphones reach a highest frequency of 20,000 Hz.22000 Hz vs 20000 Hz
8 Hz lower bass extension
JBL Synchros S100 has a lower lowest frequency than the average headphone (10 Hz vs 18 Hz). The average headphones reach a lowest frequency of 18 Hz.
4 dB/mW higher sensitivity
JBL Synchros S100 has a higher sensitivity than the average headphone (106 dB/mW vs 102 dB/mW). The average headphones have sensitivity of 102 dB/mW.
2,000 Hz higher treble extension
JBL Synchros S100 has a higher highest frequency than the average headphone (22,000 Hz vs 20,000 Hz). The average headphones reach a highest frequency of 20,000 Hz.
Direct 3.5 mm plug
JBL Synchros S100 includes a direct 3.5 mm plug, the average headphone does not. 38.8% of headphones have a 3.5 mm male connector.
On-device controls
JBL Synchros S100 includes on-device controls, the average headphone does not. 46.8% of headphones support on-device controls.
In-line controls
JBL Synchros S100 includes in-line controls, the average headphone does not. 36.4% of headphones support in-line controls.
Boom microphone included
JBL Synchros S100 includes a boom microphone, the average headphone does not. 15.6% of headphones have a boom microphone.

Calls & Controls

Why is JBL Synchros S100 worse than the average headphone?

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Fixed cable
JBL Synchros S100 has a fixed cable, while the average headphone has a detachable one. 62% of headphones have a detachable cable.
31 mm smaller driver size
JBL Synchros S100 has smaller driver size than the average headphone (9 mm vs 40 mm). The average headphones use a driver size of 40 mm.
95% lower input power handling
JBL Synchros S100 has a lower max input power than the average headphone (5 mW vs 100 mW). The average headphones handle max input power of 100 mW.
No voice assistant support
JBL Synchros S100 does not support voice assistants, the average headphone does. 60.8% of headphones support voice assistants.
4 years older release date
JBL Synchros S100 was released earlier than the average headphone (2,013 vs 2,017). The average headphones were released in 2,017.
September 2013
31 mm smaller driver size
JBL Synchros S100 has smaller driver size than the average headphone (9 mm vs 40 mm). The average headphones use a driver size of 40 mm.
What it is: Diameter of the speaker driver unit
When it matters: When you want extra hardware context behind how the headphones may handle bass weight, scale, or overall presentation.
Importance: MEDIUM
JBL Synchros S100 has smaller driver size than the average headphone (9 mm vs 40 mm). The average headphones use a driver size of 40 mm.9 mm vs 40 mm
No voice assistant support
JBL Synchros S100 does not support voice assistants, the average headphone does. 60.8% of headphones support voice assistants.
What it is: Compatible with voice assistants like Siri, Alexa, or Google Assistant
When it matters: When hands-free control is part of your daily routine.
Importance: LOW
JBL Synchros S100 does not support voice assistants, the average headphone does. 60.8% of headphones support voice assistants.
Fixed cable
JBL Synchros S100 has a fixed cable, while the average headphone has a detachable one. 62% of headphones have a detachable cable.
What it is: Cable can be removed or replaced
When it matters: When you care about easier cable replacement, simpler storage, or the option to swap to shorter, longer, or upgraded leads.
Importance: MEDIUM
JBL Synchros S100 has a fixed cable, while the average headphone has a detachable one. 62% of headphones have a detachable cable.
40.4% lower user score
JBL Synchros S100 has a lower user score than the average headphone (5.70 vs 8.000).
What it is: A rating that combines user reviews and the total number of reviews received by the headphones.
When it matters: When you want to understand how headphones perform in real listening and how reliable they are in terms of comfort, audio quality, battery life, and long-term use.
JBL Synchros S100 has a lower user score than the average headphone (5.70 vs 8.000).5.7 vs 8
6.7% worse value for money
JBL Synchros S100 has worse value for money than the average headphone (6.32 vs 6.736).
What it is: An indicator that combines the headphones' overall rating with their cost.
When it matters: When you are looking for headphones that offer a strong balance of performance, features, and price.
JBL Synchros S100 has worse value for money than the average headphone (6.32 vs 6.736).6.32 vs 6.74
4 years older release date
JBL Synchros S100 was released earlier than the average headphone (2,013 vs 2,017). The average headphones were released in 2,017.
September 2013
What it is: Official release or launch date of the model
When it matters: When you want a newer model for fresher features, longer support life, or simply to avoid buying into an older generation.
Importance: LOW
Good value: >=2020
JBL Synchros S100 was released earlier than the average headphone (2,013 vs 2,017). The average headphones were released in 2,017.2013 vs 2017
95% lower input power handling
JBL Synchros S100 has a lower max input power than the average headphone (5 mW vs 100 mW). The average headphones handle max input power of 100 mW.
What it is: Maximum input power the drivers can safely handle
When it matters: When you pair the headphones with stronger sources or dedicated gear.
Importance: LOW
Good value: >=300 mW
JBL Synchros S100 has a lower max input power than the average headphone (5 mW vs 100 mW). The average headphones handle max input power of 100 mW.5 mW vs 100 mW

Graphic comparison of JBL Synchros S100 and

Attribute category

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Third-party reviews

United Kingdom

United States

(Reviews last updated: June 2026)

What customers like about JBL Synchros S100?

Powerful, deep bass performance without distortion even at high volumes
High sensitivity allows for satisfying volume levels on lower-powered devices
Premium build with die-cast aluminium earpieces and metal accents
Tangle-free flat cable design for better management
Generous accessory package including Comply foam ear tips and a carrying case
Effective noise reduction from the earplug-like design when using foam tips

What customers dislike about JBL Synchros S100?

Sound signature is not ideal for purists due to recessed treble and boosted bass
Can produce a sense of pressure in the ear opening that may be uncomfortable for some
Below average passive noise isolation compared to some other in-ear monitors
Driver housing is somewhat heavy and thick, which can lead to a shallow fit
Remote control compatibility is split between specific iOS and Android models
Lacks active noise cancellation (ANC)

Expert reviews

consumerreports.org

Undated

JBL by Harman Synchros S100a Headphone Review

The Consumer Reports review of the JBL by Harman Synchros S100a highlights a portable, isolating ear-insert headphone with high sensitivity for ample volume and effective ambient noise reduction. It includes a 48-inch flat cord with an inline mic, volume controls designed for Android, and offers good value with a carrying case and multiple ear tip options. However, the headphones...Read more

headphone.ph

27/04/2014

Review of the JBL S100 IEM | Headphone.ph

The Headphone.ph review of the JBL S100 IEM highlights a mixed user experience, focusing heavily on its robust build but flawed physical design. In terms of pros, the reviewer praises its solid build quality, rubbery flat cord that successfully resists tangling, and a well-performing remote microphone compatible with Android and iOS devices. The inclusion of premium Comply foam tips...Read more

au.pcmag.com

19/02/2014

JBL Synchros S100a - Review 2014

The JBL Synchros S100a ($99.95) delivers a powerful, distortion-free audio performance highlighted by intense, subwoofer-like low frequency response that is tailor-made for bass lovers. Designed with flat cords and an inline remote control and microphone optimized specifically for Android devices, these in-canal earphones also feature a thoughtful selection of accessories. The...Read more

uk.pcmag.com

19/02/2014

JBL Synchros S100i - Review 2014 - PCMag UK

The JBL Synchros S100i is an affordable, in-canal headphone pair priced around $100 that targets big bass enthusiasts with a powerful, subwoofer-like low-frequency performance. Tested by audio analyst Tim Gideon, the earphones earn a 3.5 Good rating for delivering a rich, booming low-end rumble that remains completely distortion-free even at maximum listening volumes. While the...Read more

pcmag.com

20/02/2014

JBL Synchros S100a Review - PCMag

The JBL Synchros S100a ($99.95) are lauded as an excellent, bass-forward in-ear option for Android users, offering powerful, distortion-free low-end, a secure fit with Comply foam tips, and a durable flat cable. However, the, design is nondescript, and the sound signature is heavily sculpted, lacking high-frequency presence and definition for critical listening.

kopfhoerer.de

09/01/2016

JBL Synchros S100a Review

The JBL Synchros S100a is a solid, average pair of wired in-ear headphones specifically optimized for Android devices due to its inline three-button remote controller. While the reviewer notes that the build quality is highly robust and capable of surviving years of normal use, the overall sound performance lacks premium refinement. The audio profile features loud mid-frequencies,...Read more

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