Help -- sound is coming out real low on a simple radio

I have a Christmas display with one of those light/sound controllers by GE that you plug in the 6 extension cords into then it coordinates the Christmas lights on your home to the midi music that it plays. It has one speaker, I soldered in another wire for an additional speaker but after a couple of hours at full volume, the volume went out on me. It's just plays very very low now. I'm sure this is easy for most of you but I'm new to this and don't know what to look for or what to replace on the circuit board. Any suggestions?

What is the impedance of the existing speaker and the one you added?

You may have overloaded the amplifier?

Can you post a picture of the circuit board?

I don't remember what amp they use but you blow it.