Athearn MP 15 Sound Enhancment (no cost)

Truck wires run through the speaker enclosure, of which leaks +&- sound waves. Removed truck wires from speaker enclosure, glued two (white) styrene strips to prevent the wires touching the fly wheel. Smeared a bit of red on one wire as after the decoder is mounted over these wires are hard to see if switched (crossed over) Seal both hole in speaker enclosure a touch of solder and this engine has never sounded so great.