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AKG K840 KL Wireless

MSRP $299.95
This product is no longer available for purchase.

The AKG K840 KL wireless headphone employs uncompressed Kleer wireless technology for the best cord-free mobile listening experience available. The included Kleer wireless transmitter adapter is compatible with any mobile player source and provides true uncompressed CD-quality sound without dreaded cord tangles tripping you up. Long transmission range, comfortable on-ear fit and complete collapsibility for ease of travel plus extended battery life makes the K840 KL a no-brainer for enjoying footloose wire-free listening on your travels.


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Product Features:

  • Kleer wireless technology delivers true uncompressed 'CD-quality' uncompressed audio from any source
  • Kleer wireless adapter included; easily compatible with most portable audio sources
  • Charges for operation via any computer USB connection
  • Headphone works in standard 'wired' mode too
  • 24hr listening time / 1.5hr charge time

What's In The Box:

  • USB charger with USB cable
  • 1/4" full-size plug adapter
  • 2.5mm smartphone plug adapter
  • Airline plug adapter
  • Bypass cable for 'wired' listening uses
  • Premium AKG hard-sided travel/storage case


The AKG K840 KL wireless headphones has a 16-bit, CD quality 'Kleer' sound and an uninterruptible signal transmission scheme. The K840 KL features a very good 65ft listening range which allows you to connect to any of your portable audio devices found within range. The AKG K840 KL also allows you to sync to a maximum of four pairs of wireless headphones using just one transmitter once paired with a proprietary AKG auxiliary audio interconnect cable accessory (not included). Please note although the headphones are audio-compatible with Apple iPhone, iPod Touch and iPad, the AKG K840 KL does not have any microphone or voice chat capacity.

The AKG K840 KL is powered by patented Kleer wireless technology which delivers renowned high-quality acoustic clarity and excellent audio intelligibility via lossless / uncompressed signal transmission methods. It offers true lossless 16-bit audio through a stable and secure 2.4 GHz radio link. Other technical specs include an impressive 10.5Hz – 31,000 KHz frequency response, 32 Ohms impedance, 120dB sensitivity and a portably light weight of 145 grams. The battery life lasts up to 28 hours, with a 'standby' battery life maximum of 6 months.


  • Connector Type: 1/8
  • Weight: 145 grams
  • Impedance @ 1kHz: 32 Ohms
  • Detachable Cable: Yes
  • Cord Length: 1 meter
  • Cord Type: Straight Y
  • Coupler Size: Medium
  • Ear Coupler Type: Earpad
  • Headphone Type: Earpad
  • Manufacturer Warranty: 2 years
  • Sensitivity: 120dB
  • Wireless: Yes
  • Isolation: -12db ~ -16dB
  • Acoustic Seal: Closed
  • Bluetooth: Yes
  • Microphone: Yes
  • Driver Type: Dynamic

Reviews At A Glance
1 Reviews

Average Rating 
(Showing 1 of 1 review)

Very nice headphones but watch out for latency!
Posted by Robert from MA on 2011-06-24

Recommend Product: Yes
Pros: Comfortable, Nice sound, Great portability, Extra cables and connectors in the case
Cons: Very noticeable latency/delay when monitoring live audio, bass response a little low

First off let me say these are a very sleek set of headphones. They have a very refined look and feel to them with subtle cues to the amount of thoughtful design work that went into them.

The transmitter is shockingly small; I mean this thing is tiny! The hard case fits everything perfectly and seeing the pouch full of bonus cables and connectors put a smile on my face. The cables themselves feel very good. Nice and supple and seem like they are made to last. The best part is it’s all so simple and intuitive yet has finishing touches that I didn’t expect. Little, almost hidden, lights around the cable on the transmitter and charging port on the headphones light up when charging and turn off when done. It also unobtrusively blinks green to let you know they are on. They are pretty comfortable too. I have a decent size head and they fit me just fine.

I’m an audio guy so I’m going to give the sound a solid ‘Very Good’ rating. I would have liked to hear some more bass. They don’t have quite the range of the wired high end or studio headphones (nor the high end/studio price), but for what they are and how extremely portable everything is, I don’t think you could do better.

I would have kept it if it weren’t for the noticeable latency/echo. I bought these for monitoring live audio when doing video recording. I had to be wireless for various reasons and these were the only truly wireless headphones I could find that seemed like would work. I hated to return these things. The sound quality for voice was very nice but hearing yourself or your ‘talent’ speak with a delay was driving me crazy. The timing was off just enough for me to get really annoyed after the first 10 seconds of using them. I’m guessing this slight delay is due to the Kleer processing to transmit the signal and I know it is possible to fine tune the timing with some processing equipment but that would completely defeat the whole ‘wireless’ thing. I still have yet to resolve my issue.

However, if you are listening to music or even a movie where a very slight delay isn’t an issue, then buy them. All in all, this is a great setup for someone who truly wants to be completely portable and wireless. You will not be disappointed!

Sound Quality
Look & Feel

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