JBL Synchros S300a

On-ear headphones with in-line remote and microphone (White/Red)

Item #: 109SYN30WR

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Wake up your music

Need to get a little more life out of your favorite songs? Then plug the JBL Synchros S300a headphones into your smartphone or music player. Pop these smartly styled cans on your ears and even the same old songs will sound new and fresh. JBL knows more than a few things about sound, applying many years' experience in live sound and speakers to these cool-looking headphones. High-end clarity is paired with JBL's PureBass technology for rich low-frequency response.

Universal remote and microphone

The Synchros S300a headphones are a perfect match for a wide variety of smartphones. There's an in-line remote control with a built-in microphone that's compatible with the iPhone® as well as Android™ and Windows® devices. Play and pause tunes, answer calls, and even control volume with select phones.

Nice looks, built to last

At first glance, the Synchros S300a may look like around-the-ear headphones. But they actually rest against your ears. Those large leather ear cushions provide plenty of comfort to keep you listening. The headband is stainless steel, adding durability to these headphones' list of attributes.

Product Highlights:

  • 40mm dynamic drivers
  • stainless steel headband and leather ear cushions
  • in-line remote offers play/pause and call answer functionality for most smartphones, including Apple, Android, and Windows devices
  • volume control for calls and music (Samsung, Nokia Lumia, and Sony Xperia smartphones)
  • built-in microphone for taking calls on a smartphone
  • PureBass technology delivers deep low-frequency response with detail and accuracy
  • detachable cable with a 3.5 miniplug
  • folding design for easy storage
  • carrying case
  • frequency response: 10-22,000 Hz
  • warranty: 1 year
  • Our 60-day money-back guarantee

Hands-on research

What's in the box?

Download owner's manual

  • On-ear headphones (white/red)
  • 4' Headphone cable with in-line mic/remote
  • Clothing clip (installed on cable)
  • Zippered storage case
  • Quick Start Guide
  • Warranty booklet
  • Attention! booklet
  • Indication of Toxic and Hazardous Substances/Elements

Features and Specs

Fit Style On-ear
Earcup Type Closed
Noise-canceling No
Bluetooth No
Frequency Response 10-22k Hz
Sensitivity Not Given
Impedance Not Given
Weight 7.7 ounces
Cord Length 48"
Airline Adapter Included No
iPod Control Yes
Volume Control Yes
Built-in Microphone Yes
Parts Warranty 1 Year
Labor Warranty 1 Year

Product Research


Overview: The JBL Synchros S300a on-ear headphones are designed for comfort, convenience, and durability. The Synchros S300a features a padded stainless steel headband with collapsible soft leather-covered earcups for easy storage in the zippered case. The detachable 4' cable has a 3-button remote and microphone, optimized for Android devices.

Drivers: The Synchros S300a features advanced 40mm drivers that delivers powerful audio with clear highs and deep, powerful bass, just like JBL's professional audio speakers.

In-line Mic/Remotes: The Synchros S300a has a detachable 4' flat cable with a 3.5mm miniplug terminal and a 3-button in-line remote/microphone. The outer buttons control the volume up and down, while the center button controls music playback, and to answer/hang up a phone call. The controls and microphone are compatible with the following devices:

  • Playback Control, Volume Control, and Microphone: Samsung, Sony Xperia, and Nokia Lumia
  • Playback Control and Microphone Only: iPod touch (2nd gen and later), iPhone (3GS or later), iPad, Samsung, Sony Xperia, and Nokia Lumia, HTC, LG, Blackberry, Google, Android, and Windows devices.
  • Playback Control Only: iPod nano (4th gen and later), iPod classic (120 GB, 160 GB), iPod shuffle (3rd gen and later)

Storage Case: The zippered storage case lets you store your headphones for easy transport. An elastic pocket in the inner lid is for storing your cable and other accessories. The case is 7-1/2" x 2-3/8" x 6".

Specifications: The Synchros S300a has the following specs:

  • Frequency Response: 10-22kHz
  • Rated Power Input: 30 mW
  • Maximum SPL: 115 dB @ 30 mW
  • Connector: 3.5mm
  • Weight: 7.7 ounces

Our Product Research Team

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