Before you buy a sound bar speaker, read this

People love sound bars for a lot of good reasons: they eliminate most of the wiring and setup hassles associated with traditional 5.1-channel home theaters, they don't take up a lot of space, they are less expensive than subwoofer/satellite packages, and since most sound bars are self-powered, you don't need to buy an AV receiver. A skinny sound bar positioned under a sleek display is certainly a more appealing solution than a 5.1 or even stereo pair of speakers. There's just one problem: sound bars can't fill a room with sound nearly as well as separate speakers can.

Stereo-powered speakers, such as Audioengine A2s or A5+s, don't need a receiver to power them, and are no more expensive than most decent sound bar systems. They also sound better than most comparably priced sound bar systems.

That was always my assumption, so last Wednesday I listened to a pair of Audioengine A5+ ($399) speakers and a Zvox Z-Base 420 ($300) sound bar. I like the Zvox a lot, but it was immediately apparent its stereo soundstage width was smaller, and it had far less spatial depth than did the A5+ speakers spread 5 feet apart. The Zvox sounds spatially constricted next to the Audioengines. Yes, you can use the Zvox's "surround" processing to open up the soundstage a bit, but it's still nowhere as spacious as the Audioengines. The A5+s' dynamic oomph and clarity on the "Black Hawk Down" Blu-ray outpaced the Zvox as well. The sound bar was working a lot harder during the battle scenes and helicopter crash. Both systems made a decent amount of bass, but the A5+s' bass was clearer and more detailed. The A5+s performance advantages were even more apparent when I listened to CDs. Sound bars are rarely at their best with two-channel music, so if you listen to music more than you watch movies, the stereo speaker route would be a smart move.

The one thing sound bars do better than stereo speakers is they anchor movie dialogue to the center of the stereo image. Stereo speakers do the same only for listeners seated directly inline with the TV. Listeners seated over to the right will hear more right channel and listeners to the left will hear more left-channel sound. So if you tend to watch movies with more then one or two people at a time, a sound bar will create a more uniform sound experience for everyone in the room.

I used the Zvox and Audioengine systems to represent the differences in how these two types of speakers sound relative to each other. Other brands of sound bars might produce less bass, some more; some won't play as loud or lack the muscle of the Zvox. The Audioengine is good, but other speakers, such as the Emotiva Airmotiv 5 ($449 per pair) might be a bit better. But any good set of stereo bookshelf speakers will always have significant performance advantages over all sound bars. Neither test system used a separate subwoofer, but a sub can be added to either and supply more bass and increase dynamic impact.

The two A5+s have a wire connecting the left and right speakers, and they can be hooked up to a TV or cable box only with stereo analog RCA cables. I had the A5+s sitting on speaker stands, but they could be in a wide cabinet or wall-mounted. The Zvox was directly under the TV and was connected via a single optical digital cable. Both speaker systems were hooked up to an Oppo BDP 93 Blu-ray player.

Sound bars are hugely popular for a lot of good reasons, but stereo speakers can be a better sounding alternative for some buyers.

To see what your best options are, check out CNET's always-current lists of the best sound bars and the best speakers available.