Wireless Whack = Avnera Setback

Having had such a positive re-experience with the Rocketfish wireless speaker setup a week and a half ago, I was highly motivated to also evaluate a set of Avnera 2.4 GHz chipset-based Acoustic Research AWD210 ‘Wireless HD’ headphones that recently came into my possession. So highly motivated, in fact, that I didn’t fully charge them prior to doing initial testing; when I saw that the headset’s rechargeable batteries still had some out-of-box stored juice, I fired them up…to be clear, with the intention of following up with more in-depth evaluation subsequent to subjecting them to a full charge cycle.

I powered up the wireless transceiver, located directly behind the laptop’s LCD bezel, and plugged it into my dual-band 802.11n-equipped Apple MacBook’s headphone jack via the included 4′ cable. Instead of using Internet-streamed, lossy-compressed audio for my first exposure to the AWD210 set, I instead went with uncompressed ‘Red Book Audio CD’-quality material stored on my laptop HDD. After firing up the tunes, I slowly backed away from the transmitter. At 30′, I began to notice dropouts, to some degree dependent on the orientation of my head (and therefore, presumably, of the headphones’ embedded antenna). At 40′, wireless transmission was completely DOA.

This certainly wasn’t the ‘up to 100 feet’ range that Acoustic Research’s documentation claimed, but at that point I wasn’t too alarmed. The batteries powering the headset’s receiver weren’t fully charged, after all. At 30′, the transmitter-to-receiver link was impinged by two intermediary wood walls, with each wall coated with potentially RF-reflecting and/or attenuating finishing material on both sides…although I did keep the glass-inclusive doors open. At 30′, the headphones’ receiver also began to be directly bombarded by two other 2.4 GHz broadcasts; the Rocketfish transmitter, and my Airport Express. And anyway, we all know about the inevitable disparity between marketing claims and reality, right?

After fully charging up the headphones’ batteries, I tried again, this time instead deciding to stream some tunes from Yahoo Music. I plugged in the Acoustic Research transmitter, punched the headphones’ power button…and my MacBook’s network connectivity went completely haywire. I’m a bit embarrassed to be typing this narrative, because you all can probably guess the root cause right away, whereas it took me a ‘bit’ longer to figure out what was going on. I couldn’t log onto Yahoo Music. I couldn’t stream music from Sirius Online, either. Then I realized I couldn’t even VNC-log onto another system on my LAN. My final test, a ‘ping’ loop I set up a while ago specifically for situations like this:

ping -t -l 8 www.yahoo.com

was equally unsuccessful; most ‘ping’ attempts failed, and those few that succeeded had several-hundred msec to several-second latencies.

This is the point in the narrative where I get embarrassed. I disabled and re-enabled the MacBook’s Wi-Fi subsystem several times. Then I rebooted the MacBook…several times. I power-cycled the router…then the DSL modem. Nothing helped. Then I looked to the left of the laptop…and saw the headphones sitting there. I unplugged the Acoustic Research transmitter…and the MacBook’s wireless connectivity was magically restored. By re-powering the transmitter but moving it as far away from the laptop as the 4′ cable allowed, and by putting the headphones on the same side of the laptop as the transmitter (versus on the opposite side of the laptop, where they were previously), I slightly improved my ‘ping’ success. However, my overall LAN and WAN connectivity was still substantially degraded.

Ironically, I’m writing this post on the very same MacBook, sitting in-between the Rocketfish transmitter and receiver, 6′ away from the transmitter. The soundtrack to the Blu-ray version of Superman 3 is smoothly playing through the surround speakers, and as you can see below, the laptop’s Internet connectivity is also rock-solid:

It’s possible that I’ve got a bum Acoustic Research wireless headphone testbed, as was the case with the first iteration of Rocketfish gear I tried. I’m certainly open to analyzing a replacement set, if Avnera is up for a second shot. But for now, my preliminary conclusion is that while Avnera-based gear seems to be sufficiently spectrum-adept at long enough distances from other 2.4 GHz transmitters, at short range it destructively interferes with (and is destructively interfered with by) those other 2.4 GHz sources.

I suspect that Acoustic Research’s headphones would have delivered better operating range when connected to an A/V receiver, for example. But based on what I’ve seen to date, I can’t recommend using Avnera-equipped hardware in close proximity to other 2.4 GHz equipment. If your testing of Avnera’s technology has delivered a similar (or for that matter, dissimilar) outcome, I welcome your comments.

p.s…speaking of wireless audio, I’m glad to see that OS 10.5 finally delivers A2DP to Bluetooth-inclusive Apple computers…too bad the iPhone is still deficient in this regard. And based on some encouraging email conversations I’ve had in the past week, it seems that SST is finally ready to send me some MelodyWing-based gear for evaluation…I’ve only been waiting since April Stay tuned…