Synchros S300i


Premium On-ear stereo headphone iOS compatible

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The new shape of sound

Revolutionize your portable listening Now you can have your sonic revolution and carry it easily too. The new JBL Synchros S300 I breaks from traditional headphone design. Lightweight, yet durable, with a steel headband and leather ear cushions, the S300 I is comfortable for hours of pro-audio listening. Modeled after the same JBL sound systems used in the world’s most prestigious clubs, the S300 I delivers a balanced audio experience with amazing clarity and deep, powerful bass. The earcups rotate and fold in for simple, compact storage.


General Specifications

Type On-ear headphones
Maximum SPL 115dB @ 30mW
Rated Power Input 30mW

Audio Specifications

Frequency Response 10Hz – 22kHz

Speaker Specifications

Driver Premium 40mm

Control and Connection Specifications

Connector 3.5mm jack
Click here for a complete list of all specs for this product

Spec Sheet (EN)

1 MB
  • Quick-start guide
  • 1 pair JBL S300 I on-ear stereo headphones
  • 1 three-button iOS remote/microphone cable�
  • Carry Case

Manuals & Downloads

The latest owner's manuals, quick start guides, and documents.

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Synchros S300i is rated 4.5 out of 5 by 4.
Rated 5 out of 5 by from Nothing but quality I used jbl for decades and there speakers clarity and quality continues on there headphones this thing puts out clear quality sound I love it
Date published: 2016-06-28
Rated 5 out of 5 by from question I just purchase these headphones. I bought it cause I want a headphone that has great sound overall and I also like bass can anybody explain how great the bass is?
Date published: 2016-03-25
Rated 4 out of 5 by from Actually 4.5 stars The sound is good, for the first time i can hear all the instruments, i LOVE the focals, but isn't the treble is too much? Would be better if it's really balanced. And the pure bass is AWESOME, the bass is balanced, but below 30 hz i can't really feel it. It feels high quality, but i got this with the left one is a little bit loose, but overall it's really durable. I like the design did not use wires to connect between drivers and looks cool with those leathers, and with many nice touches too. Once you take one of these things, you will never want to take these off, it's comfortable. But the noise isolation is so-so, i still can hear background noises. With high durability, clear sounding drivers, looking awesome, and it's very comfortable. This is no brainer price. For 150 bucks? This is awesome
Date published: 2016-02-10
Rated 4 out of 5 by from I'm satisfied! After much searching, I am satisfied that these are excellent headphones. Are there better headphones to be had? If so, I have not heard them, and I have tried many. The S300i have that characteristic JBL sound: tight, but not overwhelming bass; a full, rich, and balanced sound; and a clarity that you can't find elsewhere. Would over ear headphones be more comfortable? Perhaps, but these fit the bill easily. My only question is what would the S500 and S700 series sound like? Can they be that much better than the S300i?
Date published: 2014-12-23
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Hi, what is the length of the cable and is the standard headphone jack provided to connect it to Hi-Fi stereo/Receiver?

Asked by: Wilson
The cable of the S300i is 1.2 meters in length and is compatible with any headphone jack, may it be from a phone, a tablet or a receiver.
Answered by: Ren at Customer Service
Date published: 2017-12-02

What is the difference between jbl synchros s300a and jbl synchros s300i? Is the differences in the cable?

Asked by: Peter001
Hi! The S300 comes in two models, S300i and S300a. One is for iPhones mainly. It has white dividing rings between the poles of the jack plugs. The other one is for Android phones. It has black dividing rings between the poles of the jack plugs. You should either buy the i or the a version, to match the phone you have.
Answered by: Nick F
Date published: 2018-08-02
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