T. Tommy - Rush (Rico Martinez Remix)

Using Multiple Speakers On One Home Theater Or Stereo Amplifier

" This is ultimately easy, but before explaining the process it is necessary to provide a warning. Multiple sets of speakers usually can not be hooked directly to a standard audio amplifier without some sort of impedance matching device. This is in reference to those persons whom might want to run speakers in several rooms at the same time (distributed audio). If several sets of speakers are run from one set of speaker terminals the amplifier will usually overheat and shut down, and may blow the output stage. These remarks do not apply to PA style amplifiers with 25 or 70 volt outputs, which require special speakers with transformers.

The correct solution is to use either an impedance matching speaker selector with the protection enabled, or use impedance matching in wall volume controls. Notice the underline in the sentence above. This is because most speaker selectors are made with a dangerous feature: a button, right in front, to disable the protection. If the switch was in back to prevent accidental deactivation of the speaker protection it would be much better. If the protection is accidentally switched off while running multiple pairs of speakers the amplifier will shut down, may blow output fuses, and very well may damage the output stage of the amplifier. There are really only 2 reasons to turn this switch off, the most relevant being that impedance matching volume controls are being used on ALL pairs of speakers. The other reason would be if only one pair of speakers are being run, making impedance matching unnecessary. In this event, though, leaving the protection switched in will make only a very small difference to the sound, so why not leave it on?

Remember it this way: only put one speaker per pair of terminals (usually red and black) on the amplifier. Do not try to use a surround amp to feed several rooms with one room on the center, one room on the rear surrounds etc. This is due to the way a surround receiver distributes the sound as you may end up with only the voice in one room and only the music in another! The correct hookup for a surround receiver puts surround sound in the main room and sound from the left and right main speakers is distributed. My recommendation for hooking up a surround receiver is as follows. Run the speaker selector from the front left and front right outputs on the amplifier. Hook your front left & right speakers to the first speaker switch on the speaker selector. You will need to re-balance your surround system by running the pink noise test as the speaker selector will decrease the output to the left and right speakers by a small amount. This allows 

running the main speakers & the other speakers connected to the speaker selector without one set being louder than the others. If your speaker selector has volume controls, you need to make sure when you use your surround system for movies the volume control is at the same setting it was when doing the pink noise test. You may hook the speaker selector to the 'b' speaker switch on the amplifier if speaker volume balance between your main left & right speakers and the rest of the speakers is not an issue.

Another variation is amplifiers with a direct speaker output for zone 2, 3, etc. These are set up to drive 1 pair of speakers, and must be used with impedance matching if more pairs are to be used. The zone outputs allow a second (or third etc) source, for example CD in one room and radio in another.

An impedance matching speaker selector provides multiple outputs from one input, and protects your amplifier from damage. Speaker selectors come with 4-12 outputs. As long as your amp has enough power, you can push as many sets of speakers as you want. Simply connect the speaker selector to your 'A' (or 'B') outputs and the rest of your speakers on the speaker selector. You can purchase speaker selectors with volume controls for each individual speaker. Another option is in wall impedance matching volume controls, which require no speaker selector. Most of these are set with jumpers at install time, providing the correct matching. If you want to run more pairs of speakers than the speaker selectors or volume controls are made for (usually 12 pairs max. depending on the hardware) you probably want a second amplifier to run the second set of volume controls (or speaker selector) from."

This is just a preview of the original article. Source & full text: www.ezinearticles.com, written by Ron D. Seaman. All rights reserved to specified author and webpage.