How to make a mini stereo speaker louder?

Hi, I bought a mini stereo speaker to connect to ipod and phone etc. but it isn't very loud. How can i make it louder? 
I opened it, theres 2 speaker magnet with 8ohm .25W, and just the wire that connects them in series. If i were to add in a battery in series would that help? Or should i make an amplifier? or adding resistors in parallel? This is just for fun and understand the circuit more!! 

Thanks to anyone who can help!

PKM2 years ago

If you just want to hear what's coming out of the speaker better, you can often make them louder by directing the sound. If you put a cone over the speaker to direct all the sound forwards it will make the sound louder straight in front of it, but quieter to the sides. Try fitting a paper/plastic cup with the bottom cut out of it over the speaker.

Of course, if you want to actually improve the speaker and understand more about audio electronics, then look into how to build an amplifier (the Chu Moy is a popular simple design). Don't put a battery in series with the speaker and your phone- that would be an expensive mistake!

You need to make an audio amp.