ZVOX SoundBase 670 Single Cabinet Sound System - Review

ZVOX SoundBase 670 Single Cabinet Surround Sound System - Front, Rear, and Bottom Views
ZVOX SoundBase 670 Single Cabinet Surround Sound System - Photo of the Front, Rear, and Bottom Views. Photo © Robert Silva - Licensed to About.com

Although Sound Bars and Under-TV audio systems are very popular these days, they just didn't come out of nowhere. ZVOX Audio was one of the pioneers in both the Sound Bar and Under-TV audio system concept and for over a decade has produced some impressive units.

Carrying on that tradition, the SoundBase 670 is one of their latest offerings in the under-TV audio system category, which ZVOX Audio classifies as a single-cabinet surround sound system. To find out if the SoundBase 670 is the right audio listening solution for your TV setup, keep reading this review. In addition, at the end of the review is a link to a photo profile which provides a close-up look at the physical features and connections of the SoundBase 670.

Product Overview

Here are the features and specifications of the ZVOX SoundBase 670.

1. Design: Bass reflex single cabinet design with left, center, and right channel speakers, subwoofer, and one rear mounted port for extended bass response.

2. Main Speakers: Five 2x3-inch full-range drivers.

3. Subwoofer: Three 5.25-inch down firing drivers.

4. Frequency Response (total system): 45 Hz - 20 kHz.

6. Amplifier Power Output (total system): 105 watts

7. Audio Decoding: Accepts Dolby Digital Bitstream audio, uncompressed two-channel PCM, analog stereo, and compatible Bluetooth audio formats.

8. Audio Processing: ZVOX Phase Cue II virtual surround processing, Accuvoice dialog, and voice enhancement, and Output Leveling to even out volume spikes.

9. Audio Inputs: Two digital optical One digital coaxial, and two sets of analog stereo inputs. Also, a front mounted 3.5mm analog stereo input and Wireless Bluetooth connectivity is also included.

10. Audio Outputs: One Subwoofer line output and One Stereo signal output (3.5mmm connection).

11. Control: Both onboard and wireless remote control options provided. Also compatible with many universal remotes and some TV remotes (Emulation Modes via PS Menu pm the SoundBase 670).

12. Dimensions (WDH): 36 x 16-1/2 x 3-1/2 inches.

13. Weight: 26 lbs.

14. TV Support: Can accommodate LCD, Plasma, and OLED TVs with a maximum of 120-pound weight (as long as the TV stand is not larger than the SoundBase 670 cabinet dimensions).

Setup and Performance

For audio testing, the Blu-ray/DVD players I used (OPPO BDP-103 and Yamaha BD-A1040) were connected directly to the TV via HDMI outputs for video, and digital optical, digital coaxial, and RCA stereo analog outputs were alternately connected from the players to the ZVOX SoundBase 670 for audio

To make sure that the reinforced rack I placed the SoundBase 670 on was not affecting the sound coming from the TV, I ran a "Buzz and Rattle" test using the audio test portion of the Digital Video Essentials Test Disc and there were no audible issues.

In listening tests conducted with the same content using the digital optical/coaxial and analog stereo input options, the SoundBase 670 provided very good sound quality.

The ZVOX SoundBase 670 did a good job with both movie and music content, providing a well-centered anchor for dialog and vocals...

For listening to CDs or another music source, the ZVOX doesn't offer a straight two channel mode, as the Phase Cue II surround sound system cannot be turned off. However, with three settings, using the Sd 1 setting provides the most vocal presence and least surround effect which is the closest you can get to a two-channel-like effect. This makes the ZVOX less effective as a serious music-only listening system, but still, provides a better music-only listening experience than many sound bar and under-TV audio systems.

Using the audio tests provided on the Digital Video Essentials Test Disc, I observed a listenable low point between 35 and 40Hz to a high point of at least 17kHz (my hearing gives out at about that point). However, there is audible low-frequency sound as low as 30Hz. Bass output as strongest from just below 50 Hz to about 60Hz. Additionally, there is a slight low-frequency output dip from about 60 and 70 Hz.

The low-frequency effects, although deep, were a little muddy, but the overall bass output was not overly boomy.

Using the SoundBase 670's bass and treble controls, you can adjust the overall output level of both the low and high frequencies, but as you lower the bass level you do lose the deep-end effect that is desirable for movie viewing.

However, one thing to point out is that while ZVOX SoundBase 670 has an effective complement of built-in subwoofers, you also have the option of connecting an optional external subwoofer of your choice. The reason this option is included is that good subwoofer performance depends on its placement within a room and where the TV located isn't always the best spot to place a subwoofer.

In other words, you may find that placing an external subwoofer in another part of the room might provide a better overall low-frequency experience than depending solely on internal subwoofer assembly provided for SoundBase 670. For more details on subwoofer placement, read an informative article from About.com Stereos.

Moving to the mid and high-end of the sound spectrum, the SoundBase 670 provided a very clear midrange, which can be further enhanced by the Accvoice setting. However, Accuvoice, although very effective at bringing out vocal presence, can also add some brittleness on the higher frequencies, depending on the content.

The midrange serves both movie dialog and music vocals well, in terms of presence, but the use of full-range drivers rather than separate mid-range/tweeter speakers did contribute to a slight dullness in the high-frequency range - which is sometimes noticeable on movies scene with flying debris/transient background elements, or music tracks with percussive effects. Also, depending on the source material, you might find that taking advantage of the three available surround sound settings in important in provided the between vocal/surround balance. As I mentioned above, in some instances, the Accuvoice feature can add some brittleness to high-frequency elements.

I used the THX Optimizer Disc (Blu-ray Edition) to do some further audio testing, including speaker/channel identification. Using the Dolby Digital bitstream, the ZVOX properly decoded the 5.1 channel signal placing the left, center, and right channels correctly, and folding the left and right channel surround signals within the left and right speakers. This results in a physical 3.1 channel system but with a full Dolby Digital 5.1 channel signal present, combined with the Phase Cue II surround settings, the SoundBase 670 projects a wide sound field (there are three surround settings provided, depending on how much vocal presence and sound field wideness you prefer).

With regards to audio decoding and processing, it is important to point out that although the SoundBase 670 does provide Dolby Digital decoding, it does not accept or decode incoming native DTS-encoded

In a case where you are playing a DTS-only audio source (some DVDs, Blu-ray Discs, and DTS-encoded CDs), you should set the digital audio output of the player to PCM if that setting is available - another alternative would be to connect the player to the SoundBase 670 using analog stereo output option.

On the other hand, for Dolby Digital sources, you can simply switch the player's audio output settings back to bitstream if you are using digital audio connections between the player and SoundBase 670.

What I Liked

1. Good overall sound quality for the form factor and price.

2. The design and size of the form factor match well with the appearance of LCD, Plasma, and OLED TVs.

3. Built-in Dolby Digital Decoding.

4. Wide soundstage when PhaseCue II is engaged.

5. Good vocal and dialog presence.

6. Incorporation of wireless streaming from compatible Bluetooth playback devices.

7. Well-spaced and clearly labeled rear panel connections.

8. Very quick to setup and use - excellent illustrated instruction package.

9. Can be used either to enhance the TV audio listening experience or as a standalone stereo system for playing CDs or music files from Bluetooth devices.

What I didn't Like

1. No HDMI pass-through connections.

2. No tweeters to extend high-frequency detail.

3. Needs more tightness on the lower end.

4. No DTS decoding capability.

5. No true 2-channel stereo-only mode.

Final Take

The main challenge of taking the characteristics of a sound bar and placing it into an even narrower horizontal form factor is the delivering of a wide sound stage. The ZVOX SoundBase 670 has a narrow sound stage out of the box with very little sound projected beyond its left and right borders. However, once you engage Phase Cue II virtual surround processing, or connect a Dolby Digital-encoded source, the sound stage does widen considerably, giving the listener the impression that sound is coming from the TV screen, and also provides a "wall of sound" across the front, and slightly to the sides, of the listening area.

However, it would have been nice if ZVOX made the Phase Cue II settings continuously adjustable rather than just offering three steps as sometimes I felt like I needed a setting in between the three presets that are offered. Also, for CD and Bluetooth music listening, ZVOX should have included a Phase Cue II Off setting in order to provide a true two-channel stereo listening option.

In terms of connectivity, the ZVOX definitely has more that you will probably need in most cases - the only shortcoming here is that the lack of HDMI-pass-through connections - but most sound bars and under TV audio systems don't provide that option either, so ZVOX is not shortchanging you in terms of its competition.

As it is currently equipped the ZVOX SoundBase 670 provides a good alternative to both a TV's built-in speakers, as well as a soundbar. It is definitely worth consideration if you are looking for something compact to provide an improved listening experience for your TV viewing experience, and is an adequate solution as a music-only system.

The ZVOX Audio SoundBase 670 is priced at $499.99 - Buy From Amazon

For a closer look and perspective, also check out my supplementary Photo Profile.