Well, for starters, your AMP is shutting down due to an overload. You have wired the speakers in parallel (Twisted both blacks, and both reds), you have effectively doubled the power it takes to drive a single speaker, as well as dangerously changed the speaker/amp impedance load. Stack both of these factors together, you are straining your amplifier to a point where its going to cause permanent damage. Don't do this. There are two workarounds. One, if your stereo has an A + B channel, just plug each speaker pair into a separate channel. This will reduce the volume of each speaker, but the internal circuitry of the amplifier will adjust to the pairs, and will not be in jeapordy due to the above factors. The second, which is basically the same as the first, but requires a speaker selector switch. These units will correct the impedance levels for multiple pairs of speakers. The more pairs you add, the more power required to drive them. IF the receiver is a 5.1/7.1 model, some brands like yamaha and denon offer a 5 channel stereo option. This drives all connected speakers at their full power limited by the power supply in most cases.