Speaker polarity is determined when connecting the wires between the amplifier and the speaker. When the positive amplifier terminal is connected to the positive speaker terminal and the negative amplifier terminal is connected to the negative speaker terminal, the speaker will be in correct polarity. App Main Features : - Check sound polarity different frequency wise and measure sound level. - Test delay level of your Audio speakers in your phone.. - Also test particular left and right stereo or earphone and also both stereo and earphone together. For a good Sound System it is essential that all loud speakers are wired correctly to get the best audio results.