Audio Systems: stereo receiver, impedance calculator, plain english explanation

Question
I bought a SONY 7.1 channel AV receiver for our home stereo.  We have 4 separate rooms with 2 speakers each.  When I connect the speakers into the available connections in the receiver, some are only putting out background music from the song.  I dont want a "surround" effect with the speakers.  I would like all 4 sets of speakers to act as FRONT speakers, but there is only 1 set of FRONT outputs on the receiver.  So I spliced and wire nutted the wires together and put them into the receiver all as FRONT.  Now the music is working, but only at low volumes.  When I increase the volume, the receiver says PROTECT and turns off.  What do I do?  And did I hurt my new receiver?

Answer
Hi Kim,

Surround receivers are not really designed to do what you're trying to do. The way the decoding and the circuitry is designed, surround information will always be sent to the surrounds, front info to the fronts, etc...

You'll need a distribution amplifier to send just plain stereo L & R to the various rooms. These can be found and places like Markertek.com or B&H online. An example of what you're looking for is below:

http://www.bhphotovideo.com/c/product/749543-REG/SpeakerCraft_CTL13164_R_MZC_64_

When you tied all of your speakers together, you have radically changed the impedance of the speakers. If the receiver's output impedance rating is a higher value than the speakers, it can damage the built in amplifier - this is why the protect mode kicks on. Here's a link to an impedance calculator: http://www.speakerimpedance.co.uk/

Be extremely careful when tying speakers together - impedance mismatches can be extremely damaging to your gear. Here's a fairly "plain english" explanation: http://www.prestonelectronics.com/audio/Impedance.htm