Home Theater Speakers

Main or Front Speakers

If you have an existing stereo system, you may be able to use the existing speakers for the front speakers in your home theater. There are several issues you should consider when reusing existing stereo speakers in a home theater:

• If the existing speakers are full range (reaching down below 80 Hz), you can probably buy a subwoofer later. For now, your existing speakers will probably do an adequate job on the low bass tones.
  
• If you current main speaker set is a satellite/subwoofer set, you are probably all set for building a full range home theater speaker system. All you need to add is surround sound speakers.
  
• Consider purchasing rear surround speakers from the same manufacturer as the front speakers. The manufacturer probably uses similar cones and drivers in their smaller speakers which will have a similar tonal sound as the mains. This is very important for a home theater speaker set. See the surround sound speakers section.
  

Surround Sound Speakers

Surround sound speakers come in several types. The difference relate to the sound radiation pattern and phase of the sound. The following list cover the major types of speakers used for read surround sound speakers.

• Direct
• Bipolar
• Dipolar

Direct speakers are regular speakers that used in all stereo systems. They probably contain one tweeter and a mid-range or woofer. Using a pair of direct speakers for the surround sound speakers is very common. For the cost, they can produce good results. You will need to play with the orientation of the speaker to produce the best sound field.

Bipolar speakers contain two sets of drivers: a tweeter and mid-range. Each set is located on opposite sides of the physical speaker enclosure. All of the drivers operate in phase, which means all the drivers move in and out at the same time. Most manufacturers recommend positioning these types of speakers next to the listen so that the drivers align with the front and rear of the room.

Dipolar speakers are similar to dipole in construction, driver count, and location. The basic difference is that dipolar speakers operate their mid-range or woofer drivers out of phase. That is, as one driver is moving out, the other driver is moving in. The is supposed to eliminate the chance that the two drivers will cancel each other out. The positioning of these speakers is similar to the dipole speakers.

Subwoofers

Probably the least understood speaker component in home theater, the subwoofer is used to reproduce only the lowest sounds. Usually the subwoofer starts working when sounds below 80Hz are reproduced. The input to a subwoofer is generally a mono signal from either your receiver or surround sound decoder.

Subwoofers come in many varieties, but the most common in home theaters include three main components: (1) an internal amplifier of varying wattages, (2) an electronic crossover, and (3) the actual subwoofer driver.

The electronic crossover is used to split the low and high frequencies from a standard signal. The low frequencies are then passed to the internal amplifier and the high frequencies are returned as output for connecting to main speakers or main amplifiers.

The internal amplifier and size of the subwoofer driver will determine how well the subwoofer reproduces low frequencies. The larger the driver and bigger the amp generally the better the sound.

The subwoofer driver is the component that actually converts the electronic signal to sound. The drivers in subwoofers come in several sizes: dual 8", 10", 12", 15", and 18". The larger the driver, the more air moved thus potentially deeper bass.

The subwoofer you choose will directly relate to the type of main speakers you currently have in your system and the type of listening you use your system.

Recommendations for Subwoofers

• Crossover bypass switch. If your equipment has a subwoofer output (a crossover is built into the decoder), you probably will want to use it as opposed to using the subwoofer's internal crossover. Thus you will want to be able to bypass the subwoofer crossover with a switch or other control.
• Opt for a remote control. The placement of the subwoofer may make it difficult to adjust the volume manually, a remote control for adjusting the volume is very useful.
• Buy the right size subwoofer for the room. There is basically a direct relationship between the size of the room and subwoofer needed.
• Frequency range reaches down to 20Hz. Subwoofers start and end their work in the two lowest octaves (a 30Hz frequency segment). If a subwoofer does not reach down below 30 Hz, it is probably not worth incorporating into a home theater.