I don’t exactly have finely tuned ears, and now most stuff is laid down with recording levels that are digitally-clipped anyway. But for true audiophiles, unclipped and uncompressed CD quality audio is the only thing that will do, and Bluetooth headphones aren’t enough.

Let’s talk data rates for a second. CD quality stereo uncompressed audio is 1.411Mbps. Bluetooth A2DP provides 768kbps max. I won’t go into a dissertation on audio compression algorithms – here’s a good one if you’re so inclined – but it’s clear that some compression is needed and some loss of audio quality occurs. I suppose if you’re listening to Spongebob Squarepants or a recent Rick Rubin produced album (listening to “Death Magnetic” right now which I still think is a great album, but fire up your favorite audio editor and take a look at those levels if you’re not familiar with this controversy), it’s not that big a deal, but there are a whole bunch of things where it matters.

With that said, I’m a big Bluetooth and Bluetooth A2DP proponent. It’s easy, convenient, nearly ubiquitous (unless you’re Microsoft, another stroke of genius in Windows 7), and does the job in most environments like the Jabra Extreme in my ear right now. But for high-end audio, there is technology other than Bluetooth, and it’s SMSC’s Kleer. A couple weeks ago SMSC announced that Daimler selected Kleer for Mercedes E-class and S-class vehicles, the first automotive application of Kleer. Brent Allen, director of product marketing for Kleer technology at SMSC took a few minutes to introduce me to this.

The choice for Mercedes is a good match – most cabin occupants are likely to be audiophiles and not that price sensitive. Mercedes is providing Kleer-enabled headsets, or there are third-party options from AKG, Sennheiser, and TDK which are completely interoperable. There are a couple other advantages to Kleer besides the 1.4Mbps audio rate that are interesting in this application.

• Kleer allows pairing to multiple receivers from multiple sources, so more than one occupant can listen to the same audio stream from a single source for instance.
• It supports audio source selection and basic remote control functions from the headphone.
• It coexists with Bluetooth and Wi-Fi on the 2.4 GHz band.
• It has 10-25m range.
• The SMSC KLR3012 receiver chip implementation has 20 mW power consumption, meaning longer headphone life between charges.

(As a side note, IR was actually used for automotive cabin wireless headphones previously, which I still can’t believe. I guess I’ve just lived in 300-day-a-year sunlight too long and take it for granted IR isn’t the right technology for any non-illusory communication, plus the bandwidth and line of sight and power consumption issues.)

I haven’t run out to pick up a Mercedes S-class or Sennheiser RS180 headphones, but the Kleer technology makes sense for both home and automotive audio where sound matters.