The Vizio S4251w-B4 5.1 Channel Sound Bar System Reviewed

Sound Bar on Steroids

Vizio S4251w-B4 5.1 Channel Sound Bar Home Theater System
Vizio S4251w-B4 5.1 Channel Sound Bar Home Theater System. Image provided by Vizio

The soundbar option for getting better sound for TV viewing has taken off like gangbusters the past couple of years, and new models appear on store shelves on a regular basis. One entry from Vizio, the S4251w-B4, adds a little twist. Although the soundbar is the main attraction, the S4251w-B4 also includes both a wireless subwoofer and two surround speakers, thus making this a full 5.1 channel surround sound system that is easy to set up and use. To find what we thought about the system, keep on reading.

What You Get In The Vizio S4251w-B4 Package

  • One Sound Bar
  • One Wireless Subwoofer
  • Two Surround Speakers.
  • Detachable power cords for sound bar and subwoofer.
  • Wireless remote control and battery
  • Hardware for optional wall-mounting.
  • Digital Optical/Coaxial, and analog audio connection cables.

Sound Bar Features

  • Number of Channels: Three (Left/Center/Right)
  • Speakers: 3-inch Mid-range and 3/4-inch Tweeter each for Left and Right channels. Two 2 1/2-inch full range speakers for the Center channel.
  • Frequency Response: 90 Hz to 20KHz
  • Sound Decoding and Processing: Dolby Digital, DTS, DTS TruVolume, DTS Circle Surround.
  • Wireless Bluetooth built-in for access of audio content from compatible portable devices. The maximum Bluetooth range is about 30 ft.
  • Wireless transmitter (for subwoofer): 2.4Ghz Band - Range is up to 60 feet (line of sight).
  • Dimensions: 42.32 inches W x 3.74 inches H x 3.15 inches D.
  • Weight: 16.1 lbs

Surround Speakers Features

  • Speaker Drivers: Each speaker houses one 2 1/2-inch mid-range driver.
  • Frequency Response: Not provided - but the observed response on the low-end was observed to be about 90-100 Hz.
  • Dimensions: 3.18 inches W x 7.42 inches H x 2.77 inches D.

Wireless Powered Subwoofer Features

  • Power output: 60 Watts.
  • Frequency Response: 40Hz - 90Hz
  • Driver: 6 inches side firing, supported by a front mounted port (bass reflex design).
  • Power On/Off via two-way switch
  • Dimensions: 6.93 inches W x 12.52 inches H x 15.86 inches D.
  • Weight: 9.8 pounds.

Set Up and Installation of the S4251w-B4

Physically setting up the S4251w-B4 is easy. The provided Quick Start Guide is well-illustrated and easy to read. Everything comes out the box ready to go. The Sound Bar unit comes with both rubber feet and wall mounting hardware for installation preference. In addition, audio cables are provided to connect the surround speakers conveniently to the wireless subwoofer.

Once you unbox everything, it is best to place the soundbar either above or below your TV. Then place the surround speakers on either side of your main listening position, just slightly behind the plane where your seating position is located.

Now comes the added convenience. The surround speakers connect directly to the subwoofer. This means, unlike most subwoofers, instead of being placed in one of the front corners or along one of the side walls, the subwoofer needs to be placed somewhere to the side or behind the main listening position (Vizio recommends corner placement), so that it is close enough to the surround speakers so that the provided speaker cables can reach from the surround speakers to their connections on the subwoofer.

The subwoofer houses the amplifiers for the surround speakers. The subwoofer, in turn, receives the needed bass and surround audio signal via wireless transmission from the sound bar.

After you have the system set up, turn on the subwoofer and sound bar and follow the instructions for syncing the two together (in most cases this should be automatic - in my case, I just turned the subwoofer and sound bar on and everything worked). Of course, before you turn anything on, connect your sources.

You have two options for connecting audio sources to the S4251w-B4:

Option 1: Connect all your sources to your TV for both video and audio, then connect either the analog or digital optical audio output from your TV to the soundbar.

Option 2: Although you can conveniently connect all your sources to the TV and then connect the audio output of your TV to the S4251w-B4, for the best surround listening experience from Blu-ray and DVD sources, I suggest connecting the video output (preferably HDMI) of your sources directly to the TV and then make a separate audio connection from your Blu-ray Disc or DVD player to the digital optical or digital coaxial audio inputs on the sound bar. This option takes better advantage of the built-in Dolby and DTS decoders are built into the S4251w-B4.

Audio Performance

The Sound Bar

In my time using the Vizio S4251w-B4, I found that it delivered clear sound. The center channel movie dialog and music vocals were distinct and natural.

Without any audio processing engaged, the stereo image of the sound bar is mostly contained with the 42-inch width of the sound bar unit. However, once the various sound decoding and processing options are engaged, the sound-field definitely widens and blends in with the surround speakers to create a very good room-filling surround sound listening experience.

Surround Speakers

For movies and additional video programming, the surround speakers delivered very good sound for their size. Depending on the sound processing mode activated, or when reproducing unprocessed Dolby Digital/DTS signals, the surround speakers projected directional sound or ambiance cues well into the room, thus really broadening both the front sound stage providing an immersive surround sound listening experience that can't be achieved by the sound bar alone. Also, the blend of sound from front to rear was very seamless - there were no obvious sound dips was sound moved from the front-to-back or around the room.

However, one observable "weakness" of the surround speakers is that when I performed an around-the-room channel test, I noticed that the surrounds were not as bright as the left, center, and right channels projected from the sound bar. The utilization of one full-range speaker in each surround speaker, rather than a two-way tweeter/mid-range/woofer combination would be the logical explanation.

Wireless Powered Subwoofer

Despite its compact size, the subwoofer had adequate power output for the system.

I found the subwoofer to be a good match for the rest of the speakers. On soundtracks with deep LFE effects, the subwoofer did reveal volume level drop-off and definition loss below the 60Hz range but provided an adequate bass response down to 40Hz for movie soundtracks.

For music, the subwoofer provided acceptable bass but lost definition with extreme low bass. One example is recordings that contained acoustic bass, although the subwoofer reproduced low frequencies, the texture of the acoustic bass was muddled.

Total System Performance

Overall, the combination of the soundbar, surround speakers, and wireless subwoofer provided a very good listing experience for both movies and music.

With Dolby and DTS-related movie soundtracks, the system did a great job reproducing both main front channels and surround effects, as well as providing adequate bass.

When I used the combination of the subwoofer phase and frequency sweep tests Digital Video Essentials Test Disc, I was able to hear a low-frequency output starting at 40Hz increasing to normal listening levels between 60 to 70Hz from the subwoofer then migrating to the sound bar and surround speakers between 80 and 90Hz, the out beyond my hearing range at about 16kHz.

System Pros

  • Very good sound delivery - better than expected mid-range presence which made for great sound vocals and distinct dialog. Surround speakers project sound into the room well, enabling a seamless surround sound listening experience.
  • Easy to set up - well illustrated Quick Start Guide.
  • Shelf, table, or wall mount option. Wall mounting hardware provided.
  • Wireless Subwoofer eliminates the requirement for a long and unsightly cable needed to connect the subwoofer to the sound bar.
  • The system provides access to audio content stored on Bluetooth-enabled portable sources devices, as well as a USB port for accessing compatible music files stored on flash drives.
  • The 42-inch width of the sound bar is a good physical match for TVs ranging in screen size from 37 to 55-inches.
  • Very affordable (less than $400.00).

System Cons

  • High frequencies and transient sounds from the surround speakers are a little subdued, compared to the sound bar.
  • Surround speakers are not wireless - require connection to the subwoofer.
  • The subwoofer provides adequate bass, but slightly boomy - needs a tighter bass image with more texture.
  • The LCD display on the remote is a nice touch, but I still found it difficult to see.
  • No HDMI connectivity - HDMI connectivity could have provided additional integration between the S4251w-B4 system and a TV, as well as providing access to the Audio Return Channel feature available on newer TVs, or access to the lossless Dolby TrueHD/DTS-HD Master Audio surround sound formats available on most Blu-ray Disc content.

The Bottom Line

The Vizio S4251w-B4 5.1 Channel Home Theater System delivered a very good surround sound listening experience, with a prominent center channel and good left/right channel image.

The center channel sounded better than expected. In many systems of this type, the center channel vocals can be overwhelmed by rest of the channels, and I normally have to boost the center channel output by one or two dB to obtain a more pleasing vocal presence. However, this was not the case with S4251w-B4.

The surround speakers also performed their job well, projecting sound well into the room and adding a clear surround sound listening experience that was both immersive and directional. However, they were a little dull sounding in comparison to the sound bar.

The powered subwoofer to be a good match for the rest of the speakers, providing an adequate bass response, but was not as deep or tight as I would have preferred.

However, when taking the features and performance of the entire system into consideration, if you are looking for a home theater audio solution for a small or medium-sized room that delivers a more accurate surround experience than a typical sound bar or sound bar/subwoofer combination, but is not as difficult to set up as, or has the clutter of, a system with individual speaker enclosures for each channel, definitely give the Vizio S4251w-B4 serious consideration - it is a great value for the price.

For a close-up visual look at the Vizio S4251w-B4 System package, including all included accessories, speakers/subwoofer, connection options, and control features, check out our supplementary Photo Profile.

It is important to note that Vizio ended it almost 3-year production run of the S4251w-B4 in late 2015, but, as of 2017 there is still interest in the product and it may be available on clearance, refurbished, or used.

However, for more current offerings, refer to Vizio's Official Sound Bar pages, as well as additional sound and all-in-one home theater system suggestions from our current listings of Sound Bars/Digital Sound Projectors and Home Theater-in-a-Box Systems - both of which are updated periodically.