well the main thing is that i want a very small speaker, something preferably smaller than a 3 volt coin cell, and it should be able to be run completely off the power of an output headphone jack (which is think would be amplified if it was coming out of a cell phone or computer right)
wow that looks perfect in size, how do i ensure that it will work directly off the electricity from a cell phone headphone port? what would i check to see if that would work out, do i have to buy it and test it?
does that mean thats the loudest the speaker will get without adding external voltage or can an amplification circuit use the same line out power and make the speaker louder without using battery power?
is it possible to make an amplifier circuit that takes no external power? just the power received from the line in?