The home theater set-up has evolved in many ways.  One such evolution is the creation of the sound bar. 

     The sound bar is somewhat of a misnomer.  It suggests a single speaker, elongated, like a bar, when in actuality it typically is more than that.  It's purpose?  To provide the high quality surround sound effect of a discrete surround sound home theater system which usually is made up of separate speakers surrounding the listener, providing 360 degree surround sound experience, such as is attained at a movie theater, in the listener's own home.   That is a lot to accomplish.  Can it be done?

     The basics.  Sound bars come in many different flavors.  There are 2.1, 3.1 and 5.1 sound bars.  However, these numbers are much more misleading when used as reference to a sound bar versus a discrete home theater system.  For instance, a 5.1 home theater system is basically the same, no matter who is the manufacturer.  It signifies 5 separate speakers, or satelites, which make up the front left/right, center, rear left/right channels  and a separate subwoofer.  Pretty academic. 

     No so with sound bars.  The numbers are now manipulated to confuse and possibly mislead the potential buyer.  For example, a sound bar may be only 2.1 or 3.1, meaning a front left/right speaker or front left/right with an additional center speaker, all packed neatly within a single long bar type speaker system called the sound bar.  But, such a system may be advertised as a 5.1 system.  Why?  Because with the use of sophisticated electronics and DSP circuitry, they are touted as simulating a 5.1 surround sound experience. 

     On the other hand, there are 5.1 sound bars which actually have built-in speakers for the front, center and rear speakers, all built into a single sound bar configuration, with separate built-in amplifiers for each channel. 

     Then there are sound bars which even include the subwoofer built into the single sound bar, for a literal single sound bar system. 

     Other systems may include subwoofers which connect to the sound bar via a cable or via wireless connection.

     How do they work?  As stated, DSP circuitry attempts to trick the ear by delaying sounds, presenting the illusion of surround sound.  Also, sound may be bounced off the walls in an attempt to cause the sound to come from the rear via reflection, to provide a surround experience.  Some manufacturers utilize their own surround circuitry, others use a generic virtual surround sound while others still use circuitry designed by SRS Labs, Dolby, etc. 

     Real comparisons between discrete home theater systems and sound bars.  Most sound bars tend to feature small speaker drivers which fit into their slim sound bar designs.  The corresponding subwoofers also tend to be smaller.  Whereas with a discrete home theater system, the satelites can be small to large, even floor standing full sound speakers, and the subs can be small or huge and capable of developing window rattling bass.  So, by comparison, sound bars typically cannot achieve the earth shaking, neighbor disturbing output of a decent discrete home theater systerm.  Sound bars are not designed for that type of output.

     Sound bars are generally geared towards the smaller room, more elegant taste.  Their design is to minimalize the unsightly wires and speaker boxes.  Instead, offering a very clean aesthetic look that is pleasing to the eye.  Not the 'bachelor pad' look of a discrete theater system. 

     Some sound bars are just speakers, nothing extra, nothing fancy.  Some, on the other hand, feature IPOD docks, built-in DVD players with Upconvert technology, FM radios, and so on.  Most sound bars come with a remote control of some kind. 

     Most sound bars are all inclusive.  That is, they do not require a separate receiver.  This is part of their attraction.  A minimalist approach offering ease of operation and simplicity of set-up. 

     The all important jack pack of the sound bar varies greatly, dependent on many factors.  With a conventional home theater system, the jack pack usually consists of audio and video inputs for many components.  Included are usually digital optical or coaxial inputs for discrete 5.1 multi-channel sound from your cable box, DVD, Blu-Ray player, etc.  The home theater receiver can usually decode Dolby Digital, DTS and sometimes their improved formats such as Dolby Digital EX, DTS-ES, and even newer versions which are supposed to be better still at providing high quality surround sound. 

     On sound bars, the jack pack is not nearly as extensive and may be even less than expected, depending on the surround sound system it employes.  Some sound bars use virtual surrounds or SRS surround formats as stated.  These sound bars may have only analog left/right inputs.  The sound of any component, DVD, VCR, Cable box, etc, is then transformed into a virtual surround sound which may or may not be similar to something like Dolby Digital Pro-Logic II, for example, or SRS's newer TRUSURROUND. 

     Other sound bars may feature digital sound inputs such as optical or coaxial.  These sound bars will have decoding circuitry to play discrete Dolby Digital and/or DTS sound. 

     Still others may have HDMI inputs and outputs and again will have the decoders of the above, but the convenience of one cable hook-up which can carry all the channels of audio and the high quality hi-def video as well.

     Now for the problems.  A sound bar can have a decoder as stated above, but still may not output very convincing 5.1 sound.  Decoding the sound and effectively transmitting it to the listener's ears without the use of separate rear speakers is a very difficult trick to perform.  In this respect, many sound bars fail, some miserably so.

     I've heard 2.1 sound bars which provided a very wide sound stage protruding several feet from the sound bar in the left or right direction, and even vertically, with the illusion of sound from above as well.  On the other hand, I've heard sound bars which can decode the discrete DTS digital signal from a DVD, yet, the sound output seems to reach hardly any farther than the physical dimensions of the sound bar itself. 

     Wireless subwoofers sounds like a great idea.  Easy placement.  No wires.  However, there may be a catch.  Since the actual speaker drivers of a sound bar are typically so small, the subwoofer of such a system may have to reproduce higher bass notes, much higher than the 40 Hz range which typifies the beginning of the lowest bass octave.  What this may mean is the introduction of directional sound waves which may distract the listener, if the listener is able to place the location of the subwoofer, thereby ruining the sound stage.

     If considering a sound bar with a separate subwoofer, make sure you have some idea of where your sound system will be situated.  If the subwoofer employs a cable which is connected from the actual subwoofer to the sound bar, then you need to know the length of that cable.  A short cable can be very frustrating after you've taken everything out of the box and realize you can't place the sound bar where you'd like.  In most cases, the sound bar cables attached to the subwoofers are not very long at all.

     All in one sound bars, meaning the subwoofers are built-in the sound bar itself, could cause issues of sorts.  Mounting on a wall may cause the bass to suffer due to the subwoofers being too far from the reflective floor and corner surfaces.  Hanging sound waves due to bass sound waves emitting from the center of a wall and bouncing back and forth between two reflective surfaces.  Even the fear of vibration from such a set-up which might cause the sound bar to vibrate itself loose, or worse yet, vibrate the expensive TV to which it is supposed to be complimenting. 

     Sound bars have a weird attribute.  The listener tends to sit directly in front of it, in order to hear the surround sound, if any at all.  Sitting way off to the side in a different part of the same room may greatly reduce any perceptable surround effect.  This is a big flaw in sound bars.  A discrete separate speaker home theater set-up usually provides fairly equal surround sound regardless of listening location within the room.

     The above attribute defeats what I believe is the consumer's best course of action, which is using their own ears to judge.  The consumer can listen to the basic fidelity of the system, looking for smooth versus hollow bass, flat versus annoying mid-bass peaks and clear, disctinct midrange, voice and finally undistorted treble without the shrillness and raspiness.  But the consumer cannot usually judge the surround sound experience, even if the sound bar is capable of providing some measure of surround sound.  Ultimately, the consumer is at a disadvantage. 

     My advice is to look for a system which is pleasing to the eye and sounds smooth and clean.  The rest is unpredictable.  Regardless of what is claimed by the manufacturer, your room acoustics, location of walls and your listening position and speaker placement will greatly effect the final sound output.  Expect great aesthetics, beautiful lines and high fidelity sound.  Anything else is a bonus.