Brian's Brain

In preparation for my early May writeup on Rocketfish's transmitter-and-receiver (the latter including a two-channel amplifier) set for wireless speaker applications, I strove mightily to uncover the product's 2.4 GHz silicon foundation. My efforts, alas, were for naught; Best Buy (Rocketfish's parent company) demurred my multiple requests. From past experience in similar situations (thereby explaining my Prying Eyes fondness), this scenario suggested to me that the company had secured exclusive (albeit likely time-limited) IC access and was in no hurry to reveal its supplier's identity to potential competitors. And as it turns out, I was right...Avnera 'outed itself' last week.

My past testing of Rocketfish's product uncovered two fundamental flaws:

1. Degradation of active 802.11g transmissions (in my particular case, on channels 1 and 11), and
2. An audible and annoying 'hum' through the surround speakers in the absence of active audio streaming

As I pointed out at the end of May, I ultimately decided to switch gears and instead go with an Amphony 5.8 GHz-based wireless system. In many respects, it was a positive shift...I no longer experienced 802.11g interference, and the amplifier integrated within the wireless receiver seemed to politely power itself down when it wasn't receiving an incoming audio transmission. But, as I mentioned in mid-June (in this particular case with respect to Amphony's headphones), my dual-band 802.11n-based MacBook laptop generates brief, periodic 5.8 GHz band broadcasts, which the Amphony receiver unfortunately interprets as valid incoming audio signals and dutifully amplifies and audibly passes on to my surround speakers.

These bursts of white noise occur most frequently (in frequency....get it? Sorry....) when my laptop and I are sitting on the couch located in-between the Amphony transmitter and receiver. But they also sometimes also happen when the MacBook and I are behind the receiver, in spite of Amphony's claims that the receiver contains a highly directional antenna. The Windows XP drivers Apple provided as part of the now-expired Boot Camp beta program do provide an option for disabling 802.11a (which I presume also disables 5.8 GHz 802.11n band broadcasts), but frankly I don't want to hassle with turning 5.8 GHz off here and back on again whenever I'm 'on the road'. So when Avnera offered to send me a second Rocketfish set for possible evaluation revisit, I took them up on their offer.

The company's PR representative passed along to me that "Avnera said that you must have received one of the very early Rocketfish rear speaker kits because the “hum” has been fixed." Indeed, it seems at least so far, the hum is gone. And, as I previously indicated at the end of May, I'm so far not noticing any 802.11g performance degradation, either, in spite of the fact that my 802.11g-based Airport Express is to the left of the Rocketfish transmitter (two feet away, on the other side of my A/V receiver, to be exact) and that the 802.11g transceiver in my Linksys WRT54GC router (with external antenna accessory) is 12 feet away, behind and to the right of the Rocketfish transmitter.

Granted, I may have inadvertently created an atypically friendly testbed for the Rocketfish gear (which I presume by default dwells in the center of the 2.4 GHz band, as is the case with many wireless-based widgets) by running my 802.11g network at the outer edges of this particular ISM spectrum swath. Nonetheless, I'm encouraged by my results so far. I'll report back any additional notable observations as I continue using the Rocketfish gear in coming days.