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JBL Synchros S400BT On-Ear and J46BT In-Ear Bluetooth Headphones Preview

JBL Synchros S400BT On-Ear Bluetooth Headphones

JBL Synchros S400BT On-Ear Bluetooth Headphones


  • Product Name: Synchros S400BT and J46BT
  • Manufacturer: JBL
  • Review Date: January 10, 2014 06:40
  • MSRP: $299 (Synchros S400BT); $99 (J46BT)
  • First Impression: Pretty Cool
  • Buy Now

Synchros S400BT

  • Rated Power Input: 30mW
  • Frequency Response: 10Hz – 22kHz
  • Maximum SPL: 115dB @ 30mW
  • Driver: Premium 40mm drivers
  • Depth (in): 3
  • Height (in): 7-1/2
  • Width (in): 5-3/4
  • $299


  • Type: Bluetooth wireless in-ear stereo headphones
  • Microphone Sensitivity: -37dBV/Pa @ 1KHz
  • Battery Charge Time: 2.5 hrs
  • Music Playing Time: 2.5 hrs
  • Talk Time: 5.5 hrs
  • Frequency Response: 20-18KHz
  • Driver: Advanced 6mm drivers
  • $99

j46btBluetooth is a device agnostic wireless streaming solution that has made great inroads into high quality sound in recent years. If you have more than one type of device in your house, Bluetooth is the only way to make sure that your new headphones will work with all of them. Bluetooth has been standard equipment in portable devices for years, so if you've bought any sort of portable player in the last few years, chances are it has Bluetooth.

JBL only makes two types of headphones - on-ear and in-ear. At this year's CES, they added a Bluetooth offering of each type to their lineup. We'll take a look at their in-ear offering first. The JBL J46BT are wireless in-ear monitors that sport Bluetooth's latest 4.0 spec. Bluetooth 4.0 has a low-energy feature which has made such small headphones possible. While the JBL J46BT aren't small for in-ear monitors, they are comparable in size to other Bluetooth in-ear monitors in size and form-factor.

One thing to be aware of with Bluetooth 4.0 is that it is the first Bluetooth spec that is not backwards compatible with previous Bluetooth specfications. While it will technically work with older devices, you'll realize much shorter wireless distances. In our experience, while normal Bluetooth can extend up to 30 feet, if you try to use a non-Bluetooth 4.0 device with Bluetooth 4.0 headphones, you'll be lucky to get 3 feet out of them. Make sure your devices are Bluetooth 4.0 enabled before you buy.

The JBL J46BT has a short, flat cable that is meant to wrap behind your neck. There are three-button in-line controls and a microphone for answering calls. The JBL J46BT has a choice of three different silicone tips as well. Battery time will vary based on use but JBL estimates 5.5 hours of talk time and 2.5 hours of music playback. Frequency response is spec'ed from 20Hz to 18kHz from 6mm drivers (we'll believe that when we hear it). The nice thing is that these are only retailing for $99, which is pretty affordable for this type of headphone.

The JBL Synchros S400BT are the company's on-ear Bluetooth offering. They can be streamed to wirelessly via Bluetooth 3.0, or you can connect the included cable. The 3.0 Bluetooth specification is much more universal and works with all Bluetooth sources. JBL promises an impressive 15 hours of use between recharges and NFC pairing for Bluetooth pairing with a tap of your phone. Control of your device is made via a capacitive touch panel on the left earcup. A mic with echo-cancelling technology is integrated into one of the cups for receiving and making calls with the Synchros S400BT headphones.

Synchros S400BT with case

The Synchros S400BT headphones fold up and come with a carrying case, a USB cable for charging, and a 3.5mm cable for connecting directly to your device if your batteries die. One of the more unique features with the Synchros S400BT headphone is that they light up in response to your touch. According to JBL:

"...an LED light trail tracks the movement of your fingers across the touch sensor – spotlighting your audio experience for all eyes to see. No wonder your head feels a little like it’s basking in victory from ear-to-ear. The S400BT: superb JBL sound that’s easy to use – and inspiring to watch."

I've always wanted a head that was basking in victory.

The Synchros S400BT headphones utilize the aptX codec with Bluetooth to provide the highest quality streaming possible (up to CD quality). They sport 40mm drivers and JBL rates them from 22kHz to 10Hz. Again, hearing is believing on that one. At $299, the Synchros S400BT are not cheap, but the plush ear cushions, steel headband, and high tech functionality seem to put them above others in the price point. Of course, it all comes down to how they sound and we won't know that until we get a pair in for review.


JBL's new Bluetooth headphones have everything you'd expect from wireless headphone, plus a little more. The relatively low $99 price point of the in-ear JBL J46BT will attract more than a few consumers. The external lights, capacitive control, NFC pairing, long battery life, and wired and wireless functionality of the Synchros S400BT will attract some buyers while, perhaps causing more than a few to look elsewhere. Honestly, it is all about how the external lights work. If they are tastefully done, they could be pretty cool. If they are gaudy, you can bet a lot of people with $300 to spend will look elsewhere.

For more information, please visit www.jbl.com.

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.

About the author:
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As Associate Editor at Audioholics, Tom promises to the best of his ability to give each review the same amount of attention, consideration, and thoughtfulness as possible and keep his writings free from undue bias and preconceptions. Any indication, either internally or from another, that bias has entered into his review will be immediately investigated. Substantiation of mistakes or bias will be immediately corrected regardless of personal stake, feelings, or ego.

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