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The generously proportioned 38-inch front unit is wide enough to provide some basic stereo separation and the subwoofer pumps out ample bass tones. However, I found the high end a tad distorted at top volumes
Bear in mind, of course, that this sound bar costs just $279 and lives at the value end of the market. It's never going to compete with a serious home theater audio setup involving a discrete amp and high-end speakers. It performs more than admirably for the price.
Performance
We would have liked to have seen (or rather, heard) greater stereo separation, but the physical constraints of the 38" front unit mean that can only go so far. I did notice the center channel (where most dialogue is passed) suffered from poor separation at higher volumes, something I remedied by boosting the center channel a bit.
Also of note, at the sound bar's default settings, I found the system's rear speakers too loud, but this is easily remedied with a few touches of the remote.
Since the system relies on an optical connection for its audio, it can accept and decode compressed formats such as Dolby Digital and DTS. However it won't give you the uncompressed audio that HDMI can deliver. Again, however, this is something we'd only expect to find on a higher-end unit.
When I tested the S3851W using scenes from Skyfall, Collateral and Breaking Bad, it performed admirably, delivering a very engaging experience. My video game testing was similarly successful, with Uruk-hai hordes coming from behind feeling appropriately menacing.
The subwoofer performs surprisingly well for its size and is able to reproduce deeper bass tones than I was expecting. If the system falls down anywhere, it's in the front stereo separation. With the right and left channels chained to each other, there's only so much it can physically do with the sound, though.
In terms of music, the unit performs decently if not spectacularly. The fake-surround version of 2-channel audio sounded eerie and artificial, but with surround turned off it was passable, with the subwoofer doing an excellent job on the low end.
Again, right and left separation is the primary issue, along with a lack of the overwhelming power a high-end stereo can provide. If you don't need to crank it up and plan to use it primarily for casual listening, it does quite well and the inclusion of Bluetooth is a great touch.
We liked
The wireless-sub-to-wired-rear-speakers approach is a winner. Instead of mucking about with virtual surround voodoo, this system puts actual rear speakers behind you, a great approach that delivers serious value at this price.
The subwoofer is a wonderful surprise, offering great performance in a small package. In addition, the setup is almost eerily painless and the price-to-value ratio is right in the sweet spot.
We disliked
The system lacks HDMI support, which is a bummer given its plug-and-play nature. I also found some distortion when I turned the volume way up.
Probably the biggest performance negative is the limited stereo separation on the front right and left channels and some muddiness in the center channel. Also, the rear speakers do feel a little cheap, but again, for the price I can't really argue.
Verdict
Hands down, the Vizio S3851W-D4 is a strong product at a stronger price. If you're currently listening to movies through the speakers on your TV and are looking for an inexpensive step up, this is a great choice.
But even those who already own audio system should consider this option. If you have a low-end system without a subwoofer, this is also something of a no-brainer upgrade.