I'm looking for a simple circuit to get the most noise I can out of two 2W (max. 3W) speakers attached to an UNO, without blowing them up!
The speakers I'm using are http://www.visaton.com/en/chassis_zubehoer/wasserfest/k50wp_8.html
Sound for both will be generated of the same pin on the UNO, and it's just simple pulsed tones at two different frequencies, so sound quality isn't too big a concern.
Having had a search of the forum, I've found this diagram -http://sites.google.com/site/vanyambauseslinux/_/rsrc/1298081054520/electronics/arduino-generator-signalov/fast-pwm-sound2.png
(from this thread
And is the simplest circuit I've found so far, however I'd like to drive it with more than 5V, but I'm not entirely sure how to calculate the necessary resistor sizes (is it just a simple case of using the resistance/power rating along with the usual equations?)
This project will be getting powered from a 12V car battery, but to keep power consistent for the speakers, I'll probably add a 9V regulator just for them.
Is this circuit the simplest way to get reliable sound, or should I be looking at something different?