Kit: MX645R with dual SugarCube24X15X06-2W; 3x 470uF Flat Tantalum Capacitors
Heljan's OO Class 23 doesn't have a lot of space, so for an easy install, we'll be quite limited on speaker choice.
Shown here with a standard decoder on board...
A dual SugarCube24X15X06-2W sits comfortably on top of the model's circuit board. We're also added an array of 3x 470uF Flat
Tantalums capacitors for stay-alive.