The SM 210 is so large that I lowered my shelf and mounted the Power Pack on top. This only hides the off-on switch and I use a remote switch at the plug. The sound push buttons and volume controls are all handy. I use this on my small N scale

A slide out shelf holds the SoundMaster under my new N scale layout. This is the best way to have steam engine sounds coordinated with the motion in N scale. I may buy a third one just for the future.

I couldn't fit the on-board module in an N scale train, so I permanently mounted it to the SoundMaster. The short track is powered and transmits the signal to the antenna between the rails. Sounds good, even with the original small speaker.

The on-board sound system modified for small scale. I step my accessory power 12 VDC down to 9 VDC to replace the battery. Only needs my 12v power and the rail signal to coordinate the steam chuff and transmit that signal to the wire antenna between the rails.