Hi My brother has a logitech pure fi anytime alarm clock radio. The problem with it is that when it is cold the speakers do not work properly distorting the sound. This is not very useful as it is cold in the mornings when the alarm goes off (playing a song from the ipod). Now I had an idea that I could use a bank of resistors to heat the speakers so that they would operate normally all the time. I have basically used the same idea as a dew heater for a telescope (http://www.dewbuster.com/heaters/heaters.html [Broken]). this is my idea I am just a bit worried that the resistors would end up overheating. My question is would it be possible to use a PTC thermistor in the circuit to prevent overheating?