Built-in DVD player
For the ultimate in ease of use and convenience, many Home Theaters in a Box come bundled with a DVD player. Most of the time, the DVD player is built in with the main amplifier unit. This makes setting the system up easier as there are fewer cables to connect and eliminates the possibility of hooking it up wrong. There are some disadvantages, however, of the built in DVD player. It is not possible to replace just the DVD player if it should fail prematurely. It usually is possible to connect an external DVD player in this case.
Without DVD player
For those who want to use their own DVD player, it is possible to buy some systems without one included. Most home theater units that include a built in DVD player don’t usually spec it with the best of players, so if you are picky about your picture quality you might want to opt for a system without the built in player.
Some systems don’t have a built in player, but will still include one in the bundle. This gives the user the advantage of upgrading the player down the road or even replacing it if it should fail. With this option though, there is always the possibility of getting confused on the hookup, since there are cables that will need to be connected.
Powered vs. non powered subwoofer
Virtually all home theater systems will come with a subwoofer. A subwoofer’s primary responsibility is to reproduce the low frequencies. These frequencies are low enough to be considered “non-directional.” In a sense, the human ear can’t tell from which direction the sound comes. This allows the user to place the subwoofer virtually anywhere in the room.
The less expensive systems will include a subwoofer that is passive. This means the woofer relies on power from the main amplifier. These systems usually don’t have the same “punch” that more expensive systems have. More expensive systems will include a powered subwoofer. Two amplifiers are included: one for the main speakers and one built into the subwoofer. These systems usually have much better bass response and tend to “kick” a bit harder.
This is the simplest form of home theater. A 2.1 home audio system will consist of 2 speakers and a subwoofer. The subwoofer frequency isn’t a full range signal, hence the .1 designation for the channel. The 2 included speakers will consist of a right and a left channel. Many more expensive systems will use sophisticated systems to decode the rear audio signal and produce it out of phase so that when it bounces off the rear walls of your room, it will appear as if it’s coming from behind the listening position. The Bose 321 is an example of this kind of system.
5.1 surround systems include 5 speakers and a subwoofer. Typically, there are 3 speakers place in front of the listener and two behind. The front 3 speakers include the left and right channels as well as the center channel speaker. The center channel is responsible for reproducing all the dialog of a movie, as well as pretty much anything that is happening on the screen. The rear speakers’ duties are to reproduce the ambient sound effects of the movie, i.e. if the plane flies overhead, the sound will follow it to the rear speakers.
7.1 and beyond
Many systems now will include more than the typical 5.1 speakers. The idea is to add more surround channels to give a better ambient effect. This enhances the listening experience by allowing the speakers to better recreate the ambiance of the current scene.
THX, DTS, and Dolby
Systems that have a THX logo mean they have passed rigorous testing. This certifies that the amplifier is capable of sustaining audio at “reference” levels over time in a specific room size. This is why there are different levels of THX certification, such as THX Ultra or THX Select. It is important to note that THX isn’t its own surround system like Dolby and DTS.
Dolby Digital is the starting point for digital surround sound. A system with Dolby Digital decoding is capable of decoding the discrete 5.1 channels for 5.1 systems. DTS is similar to Dolby Digital in that it is its own surround system. It uses a different compression technology and is regarded by many in the industry as the superior surround sound option.