AV Receiver Reviews

Performance

It was immediately obvious that the Zvox Audio Zbase 580 system sounded a lot better than the speakers in my LCD TV, although that’s not saying much. So let’s get more descriptive. The sound was fuller, clearer, louder, and more realistic in every way. In other words, when you add the Z-Base 580 to your skinny flat-panel TV, the sound goes from intolerable to satisfying.

Here’s an example: On the Blu-ray of Monsters vs. Aliens, you can now hear the guttural roar of Insectosaurus (the cute, colossal bug monster shown above) reproduced with all the gusto that a good home-theater-in-a-box system would deliver. You hear plenty of bass during the movie’s numerous crashes, explosions, and monster/alien battles. You hear a reasonably good wraparound sound effect in the scene where aircraft whiz around the U.S. President when he confronts a giant one-eyed mechanical alien something-or-other. Most important of all, voices sound far more natural and easier to understand.

In fact, the vocal reproduction sounded pretty good no matter what Blu-ray or DVD or TV show I was watching, and no matter which actor was speaking. There does seem to be some midrange emphasis, but it’s not overt and it can make voices more intelligible. I would call this actual voice reproduction, as opposed to the voice approximation you get with most flat-panel TVs. The performance of the Z-Base 580 in this regard is comparable to that of the best soundbar systems I’ve tested.

The Z-Base 580 can play quite loud in the middlebass region, where action movies get their punch and impact. It can even deliver respectable deep-bass output, comparable to what you’d get from a good small sub. Its bass is kind of a happy medium: enough bottom end to satisfy you, yet not so much that it’ll annoy others in the house or the people in the adjacent apartment.

The PhaseCue II processing gives you three options. Setting 1 provides near-zero surround effect; it’s fine, but a little boring. Setting 3 gives you a huge wraparound — but disembodied — sound with near-zero center image. Of course, Setting 2 falls in between, and that’s the one I used for most of my listening. The surround effect is only moderately enveloping, which is why I started to think of the 580 as more of a high-quality TV sound system than a substitute for a 5.1 system.

The Dialog Emphasis feature boosts and compresses midrange to enhance voices. I didn’t dig it at all. It over-accentuated the upper midrange something fierce. To me, Dialog Emphasis made the 580 sound more like the TV’s internal sound system. The Output Leveling feature was no more useful. Like other such features I’ve tried, it produces seemingly random volume fluctuations. No great loss, in my opinion, because I’ve never been sold on the need for this feature.

Bottom Line

I’ve tried at least 25 soundbars, but the Zvox Z-Base 580 is one of the few that does what I most want a soundbar to do: work with my TV’s remote. It’s also easier to set up than any other soundbar I’ve tried except other Z-Base models. And it sounds far, far better than your average fl at-panel TV, and better than many, perhaps most, of the soundbars out there. If you’re looking for an easy way to get better sound from your TV, you’ve found it.

Test Bench

Frequency response

51 Hz to 20 kHz ±10.8 dB, 300 Hz to 10 kHz ±9.7 dB

Bass output (CEA-2010 standard)
• Ultra-low bass (20-31.5 Hz) average: 86.6 dB

20 Hz         NA
25 Hz         89.0 dB
31.5 Hz      99.8 dB

• Low bass (40-63 Hz) average: 106.1 dB

40 Hz         102.2 dB
50 Hz         105.1 dB
63 Hz         110.9 dB

I measured the frequency response of the Z-Base 580 by placing it atop a 2-meter-high stand and positioning the microphone at a distance of 2 meters, enough to incorporate the contributions of all the drivers and the diffraction from the cabinet edges. The curve you see here represents an averaged response from 0° to 30°, smoothed to 1/12th of an octave, with the mike aligned with the center midrange/tweeter driver. The PhaseCue mode was set to 1 to minimize the effects of the phase processing on frequency response. To get the bass measurements, I close-miked the woofers and the rear port, added their responses, then spliced that to the averaged response curve at 300 Hz.

The Z-Base 580’s frequency-response measurement would be a lot, lot better but for an 18-dB dip centered at 6 kHz. That dip is only 1/2-octave wide and high in frequency, so it should be barely if at all audible. Up to 5 kHz, the response measures ±4.0 dB, which is pretty darned smooth for a soundbar. Further off-axis, at 45° and 60°, the tonal balance remains surprisingly flat, with very little treble rolloff, although the midrange response between 300 Hz and 1 kHz drops by about 10 dB.

I also ran a measurement of just the left driver, with the microphone positioned directly in front of the driver and 2 meters away, and only the left channel fed with a signal. Surprisingly, the resulting measurement looked generally similar to the measurement from the center drivers, although it was about 6 dB lower in level, as might be expected.

The surround modes 2 and 3 reduce the level in the center drivers by 3 and 6 dB, respectively. They do affect frequency response, but only above 5 kHz, and the effects aren’t major. The Dialog Emphasis mode doesn’t seem to have an appreciable effect on frequency response; its effects must be due primarily to frequency-dependent compression. There are also treble and bass controls on the remote. The treble control has a range of settings from +4 to -4. It’s effective from about 2.3 kHz to 9 kHz, producing a maximum boost or cut of ±7.2 dB at 3.6 kHz. The bass control has a range of settings from +4 to -8. Maximum boost is +7.4 dB and maximum cut is -14.5 dB, both centered at about 85 Hz.

Bass output (measured at 2 meters, and with 6 dB added to approximate results at 1 meter) was roughly comparable to that of a decent 10-inch subwoofer, with pretty good output of 106.1 dB in the low bass (40-63 Hz) and measurable output down to 25 Hz. Although there was no measurable output at 20 Hz, I used the 25-Hz number minus 18 dB as the 20-Hz number to derive the 20- to 31.5-Hz average, as per CEA-2010 rules. —B.B.