After receiving my package from Tonys Train exchange, with my DCC system and sound decoder etc,  I started the installation in the Vanderbilt tender which has limited room in width to install a round speaker. So here are some shots following Erik from Tonys Train Exchange advice , using 2 new mini speakers.

Amazingly small TCS Wow sound decoder to install in tender

This decoder has many choices of bells, whistles, engine types, all manner of mechanical injectors, pumps, generators, brake squeal, air release as well as light control and great control of the running engine including very slow speed right out of the box.

Drilling sound holes on drill press

Holes need to be drilled through the tender bottom to allow the sound exit.

Holes drilled for sound and test fitting speaker enclosures

Checking the fit of the mini speaker enclosures.

Engine and Vandy tender, showing TCS sound decoder installed, before mounting speakers.

Showing the decoder installed in top of tender with strong double stick (Scotch exterior mounting tape)

2 Supersonic Mini speakers installed in Bachmann C&O Vandy tender bottom

The 2 mini speakers and their enclosures mounted and wired in the tender bottom.

Bachmann Heavy Mountain engine with Sound decoder installed, and the sound and control are really terrific.

Engine after install and really pleased with the result, the sound and control.