Technical info on speakers
August 29, 2010
Hello guys. I've made a simple audio board by following the instructions provided by the "Arduino Waveshield" homepage. Only changed one part (the audio amp) but it works flawlessly.
Now, i'm using a 1W audio amplifier, and i have an 8ohm 0.5W speaker. I'm not too satisfied with the volume, as i'd like it louder than it currently is. Options are:
1) Change amp, find a more powerful (more watts) one. Problem is i'd like to stick with my 5V supply, and most powerful amps i've seen require a larger power supply, except some that only come in QFN though (i'd like mine in DIP, because i'll eventually have to solder it in a protoboard)
2) Change speaker. Now this second option is the main focus of this post. The previous Amp i've mentioned supports 8 ohm speakers, and i've scavanged a few speakers from around my house, problem is they are rated at 4 ohm. Can i still run it by placing a 4ohm resistor in series with it. Is this gonna "change" something (well, amp should be fine as it will have it's 8ohm load...but i guess that means less output)? Second question: what does the Wattage rating on speaker actually mean? From the very very basic knowledge i know P = I * V or P = V^2 / R ....so ok, we got the resistance, but how can we determine the wattage without knowing the supplied voltage?
Thank you :=)