How to get people to interact in a group or presentation
Test the speakers, wires, and polarity all in one step!
If you are wiring a car stereo or home stereo and have the wires plugged into the speakers but at the other end do not know which wires go to which port? Rather than trace each wire seperately, grab a 9volt battery, hold one wire on a terminal, tap the other wire on the other terminal, and it will make the speaker pop. Now know which speaker is connected to that wire.
Also, if wired correctly +/- the cone will pop OUT; if it sucks in, you have the polarity backwards. Too steps solved in one. You want all of the speakers to pop out with the +/-. This will make your stereo, home or car sound much fuller. If it sounds hollow or lacking bass, you may have just one speaker wired backwards.