Can running multiple inputs into one speaker cause damage?

Question

In my gameroom, I have boht my receiver (for my tv//playstation) and my PC hooked up to the same speakres (a 5 speaker surround sound system). So each speaker has 4 wires coming into it instead of 2. This has been working for about a year, although if the bass gets too loud on my receiver, it will shut it down and display "Check SP Wires". I typically unplug my PC subwoofer to avoid this happening.

Well I tried to watch some youtube on my PC today and the PC speaker system no longer works. My satellite speakers all work fine (I checked them via my receiver) and my sound device on the PC is working properly according to windows, so I think it might be my PC subwoofer.

I tried unhooking it all and then hooking the PC Subwoofer up to a separate speaker (by itself) to see if it would work and it's not. I turn the volume all the way up and I can BARELY hear anything if I put my ear right to the speaker (normally this system will make the room shake). Any thoughts?

Answer 1

Connecting more than one output to a speaker will not damage the speaker but can destroy one or both amps connected.  What happens depends on whether both amps are powered on, and if signals are coming from both amps.  What can happen under the right (wrong?) conditions is that one amp can "short out" the other, drawing excess current from both.

Answer 2

Aside from the informative and correct answer already given... your subwoofer is toast. Also known as "blown"

And connecting multiple signals (via amps or sound cards or what have you) with speaker cable is not wise unless you understand series and parallel wiring techniques and use only one power source (amp).

There are factors of impedance and you're lucky your receiver shut down before too much damage was done to it (though some damage occurs before shut down).

Sounds like the sub isn't self powered, it probably received a signal (impedance and wattage) it couldn't deal with - now it's dead.

Sorry.

Now you know not to do that, use a splitter next time that separates the "line level" signal (what patch cables transmit -RCA cables).