The speakers receive a stereo signal from the included 2.4GHz transmitter. Not much larger than a Treo smartphone, the tiny unit will slip into whatever extra space you have in your equipment rack. The always-on transmitter is AC powered, of course, and needs to be tethered to your primary audio source--a DVD player or an A/V receiver, for instance. The only connectivity available is a single pair of line-level RCA inputs. That means the transmitter will interface with any piece of audio/video gear with an analog A/V output or even just a headphone jack (a minijack-to-RCA adapter cable is included).
Unfortunately, the single stereo connection limits the usefulness of the entire On Air Control system when connecting to A/V receivers. Whether you want to use the On Air Control 2.4G speakers as the rear channels in a 5.1- or 7.1-channel surround system, as front stereo speakers, or as Zone 2 speakers in another room, your A/V receiver will need to have preamplifier outputs. The problem is few moderately priced ($500 and less) receivers are so equipped. Why JBL engineers didn't include speaker level inputs on the transmitter to ensure universal compatibility is impossible to fathom, and we guess the RCA-only input scheme might be a deal breaker for some potential buyers. On the other hand, JBL is already saying this is merely the first product in a larger On Air wireless speaker lineup, so it wouldn't be a surprise to hear that a system with speaker-level inputs is on the drawing board.
JBL claims a 70-foot transmitting range, but we were able to go up to about 100 feet before the signal died. The crowded 2.4GHz wireless band can experience interference from cordless phones, wireless networking equipment, and even microwave ovens, but neither wireless telephones nor a Wi-Fi-soaked environment caused any problems for us. Of course, both issues--transmission range and interference--will certainly vary from location to location. Interestingly, both of the AC adapters are compatible with world voltage standards, and JBL even includes international prong-style power cords (in addition to the standard North American ones). We suspect that means JBL can ship and sell this single system pretty much anywhere on the globe.
After we figured out where all the wires and power supplies went, system setup was hassle free; as long as both the transmitter and the speaker are set to the same channel, you should be good to go. The small remote controls volume and mute, and toggles between two inputs (the wireless transmitter or the speaker's line-in), but it's not a very great clicker. Not only does it need to be pointed directly at the left speaker to work, its four tiny membrane keys weren't always responsive--we sometime had to press the mute button two or three times before it engaged. Another annoyance: the left speaker's two LED indicators (power/mute and input) are irritatingly bright in a darkened home theater, and there's no way to dim them. Also, when we weren't playing any music, we detected a very faint hiss/noise coming from the speakers.
Once the system was up and running, it was finally time to sit back and listen. Most wireless speakers are bass shy and sound mildly distorted all the time, but the JBL On Air Control 2.4G sounded like a conventional wired speaker. Treble detail is soft and lacking in sparkle, but that also means the speakers are very easy to listen to. James Taylor's sweet folk tunes sounded natural, but Aerosmith's hard rock was less convincing. The compact size of the speakers and the 15 watt amplifiers do have their limits after all; pushed hard, the sound turns harsh and dynamic punch suffers. That won't be a concern when the speakers are used as surround speakers, which are generally played at a much lower volume than the front speakers. And that is, we suspect, the On Air Control 2.4G's prime mission.
Used as front speakers for a two-channel home theater, the On Air Control 2.4G were at their best on quieter DVDs: dialog sounded rich, if slightly lacking in clarity, but action movies felt reined in by the system's limitations and special effects had very limited dynamic impact. We did audition the On Air Control 2.4G with and without the assistance of a NHT SW10 MkII subwoofer. The sound is richly balanced so we imagine most buyers won't need to add a sub, and the NHT's contributions couldn't make the JBLs sound like larger speakers.
Still, while the JBL On Air Control 2.4G didn't blow us away, the fact it was even able to hold its own versus wired speakers can't be discounted. The sound quality will be more than satisfactory for anyone who's not a serious audiophile, and that's why we're giving it high marks. In the final analysis, if you can live with the system's connectivity limitations, the JBL On Air Control's plug-and-play setup and solid sonics make it a worthwhile solution for anyone who needs the flexible placement options offered by its wireless capabilities. Just don't expect a system that's completely wire-free.