Square the voltage then divide by the resistance (ohms):http://i76.photobucket.com/albums/j23/steveo200077/RMSchart.jpg
any idea how I could go about finding about how much rms 8 volts
at 4 ohms would be in watts ?
I need to find a little car amp that will give off around 20w rms each channel ( 2ch)
for a portable boom box im making using 2 small 12v batteries from emergency lights
and using speakers that are 15w rms each.
found this on ebay, http://cgi.ebay.com/LPV8-Hi-Fi-Audio-Stereo-Amplifier-Amp-Mp3-Ipod-for-Car_W0QQitemZ120391386956QQcmdZViewItemQQptZCar_Amplifiers?hash=item120391386956&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A15%7C39%3A1%7C240%3A1318
curious if it will fit my needs or not.