A more powerful speaker

The signal coming into our speaker was too weak to make a strong sound. We picked up a 3W signal amplifier kit from Radio Shack (Velleman K8066). T got to practice soldering hookup wire to alligator clips to get started. We (mostly I) soldered the kit together with a 9V battery for a power source. We mounted it on a small cardboard box and added an on/off switch "to make it more official" as M said. It works! The audio is as strong or stronger that the speakers on my laptop. It does very well with higher pitch "violin" range. I played Vivaldi, Four Seasons, Winter on it and T accused me of tricking him and actually playing it off the computer speaker, it was so clear and strong. It does poorly with lower human voice range (I tried Kennedy's speech at Rice University and his May 25, 1961 speech before congress but they were unintelligible), which probably helps explain why it was such a bad microphone for our voices. One interesting thing, when I played recordings made from using it as a microphone, back onto it as a speaker it shook like crazy. This demonstrates inducing mechanical resonance from the natural way the setup tends to vibrate. One last tweak I would like to add is a switch for flipping between unamplified microphone mode and amplified speaker mode.