4K TV Reviews

Logistical issues (i.e., the inability to operate the soundbar independent of its 65-inch UHDTV host) kept us from performing our usual set of anechoic audio measurements on the Vizio audio system. But I took some in-room measurements from the two listening positions I used. The tests were run using the OmniMic measuring software from Parts Express and its calibrated microphone. The audio controls were set to what offered the best results in my room—determined by ear before any measurement were taken.

The in-room response curves curves are shown in figs.1-4 below. They were each taken a single microphone position at seated ear height in the center and left seats respectively. One-sixth octave smoothing was applied. Averaging multiple microphone positions didn’t yield significantly different results.

From my favored (for movies) left of center seat, the in-room response of the system was remarkably smooth from about 220Hz up, though a little less so on the right channel. From there down there were a few notable peaks and valleys in the response, but nothing unexpected in a typical room. In fact, the subwoofer extended down to a strong 30Hz before plunging rapidly below that point. Does this mean that this small subwoofer can challenge the performance of big-boy subs? Not really; they’ll likely have the ability to play louder at this low frequency, with lower distortion. But the system’s measured bass response was still impressive. Above 10kHz the response dropped off rapidly on both channels—typical of a small woofers in a small, shallow cabinet.

The results from the center seat weren’t as smooth on either channel as from the left seat, but weren’t alarming either. A bit more pronounced high frequency rise was noted from the center listening position in both channels (between 5kHz and 10kHz)—as was heard in the listening tests. And the bass, while still extended, wasn’t as flat. In short, the measurements supported my preference for the left seat.

Of the measurements I took of the soundbar with the sub turned off, the most notable result was a sharp rise around 150Hz followed by a steep rolloff below that frequency. Without the subwoofer I’d judge the effective bottom end of the soundbar’s performance to be about 125Hz. This isn’t surprising considering the estimated size of the drivers in the soundbar and its shallow cabinet. That 150Hz hump, though not off- putting with the sub in operation, may have contributed to the slight fatness I sometimes heard on male voices particularly at high playback levels. Note, also, that the bar’s lack of response below 125 Hz could result in some localization of male voice if the sub is placed at the back of the room opposite the bar as Vizio recommends. —TJN