Like many speaker docks, the OnBeat Xtreme is designed to deliver the best sound at a slight upward angle. So when I measured the frequency response, I placed it on a 5-foot-high stand rather than the 2-meter-high stand I normally use. This freed me to put the measurement microphone at a higher angle. Using my Clio FW audio analyzer in MLS mode, connected through the OnBeat Xtreme’s 3.5mm line input, I got quasi-anechoic measurements down to 300 Hz. (Quasi-anechoic measurements remove the reflections from nearby objects to simulate measurement in an anechoic chamber.) To get the response below 300 Hz, I ran a ground plane measurement with the Clio FW in log chirp mode and the OnBeat Xtreme and the microphone placed on the ground 2 meters apart. I then imported the data into my LinearX LMS analyzer for post-processing. The graph here shows a quasi-anechoic measurement at 0° on-axis (red trace) and an average (blue trace) of the measurements at 0°, ±10°, ±20°, ±30°. The quasi-anechoic measurements are smoothed to 1/12th octave, the ground plane measurement to 1/3rd octave.
It’s hard to believe that a speaker dock could measure this well. With almost all docks, those plastic protrusions and non-acoustically transparent grilles cause sound reflections that result in extremely ragged frequency response. Yet the OnBeat Xtreme not only measures better than any dock I’ve tested, it measures better than the vast majority of speakers I’ve tested. On-axis response is ±1.89 dB, while averaged response across a ±30° window is ±2.54 dB. You can see from the chart that there’s almost no difference in on-axis versus averaged response. The -3 dB bass response is a very low 38 Hz, although the device’s output capability at that low frequency is negligible.
Note that while it’s entirely possible for anyone doing speaker measurements to screw up a frequency response sweep so it looks worse, it’s almost impossible to make a speaker’s quasi-anechoic measurement look artificially good.
The OnBeat Xtreme is a nearly miraculous product, almost entirely free of the nasty sonic colorations that plague most iPod docks. I prefer its sound not only to that of most of the iPod docks I’ve heard, but even to many of the desktop speaker systems I’ve heard. If you’re the type who really wants to crank up your favorite tunes to party level, this isn’t the dock for you. But it you’re the type who’s been hoping for real audiophile-grade sound from a simple, all-in-one product, you’ve found it.
Brent Butterworth and Geoff Morrison combine their years of gear testing and knowledge in one überblog of irreverence and techiness.
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