testing speakers and amp

Years ago , before I was doing my own installations i had several amps and subs blow, the place I used to buy my equipment from tested them to be sure they where no good before sending them in , They would have me bring it in and they guy would use a device to test it, anyone know what this would have been or how to do it, I think it would be really handy to know. Thanks

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ThedudeabidesJess30

To test an amplifier, you need a 12 volt power source, a signal source to drive the amp and a speaker or two to listen to it.  A junked computer power supply is usually a good source for a 12 volt power supply.  Even the smallest ATX supply can provide around 15 amps of current at 12 volts.

I do know that 15 amps is not enough current to see if an amp is producing maximum power.  But it will let you know whether or not the amp is working. 

hey thanks , wasnt having the problem lately , just always bugged me I didnt know how to do it. Could have sworn he did it right on the counter in the store though, probably wrong though its been a while.

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ThedudeabidesJess30