Before fixing the major components to the locomotive floor, it is necessary to organise an electrical pickup from the track or from the motor for the soundcard. In this case, the purple and grey wire has been connected to the red wires which link the two bogies and then to the soundcard M1/M2 terminals.
The soundcard, speaker and a 3.6 volt NiMiH cordless phone battery were fixed to the locomotive floor using double sided tape. You may want to paint the battery and other components matt black before installation so that they are not visible through any vents, grills or windows which your locomotive may have.
It is worth experimenting with the position of the speaker, whether it is installed facing up or down and how it is covered. All these factors will change the sound produced and can improve the bass tones. Just place your hand over the speaker when it is running to see how the sound can be changed.
In the example, battery has been connected direct to the soundcard. In that case, care should be taken to avoid a short circuit during soldering.
Once the soundcard settings have been set for the type of loco then you are ready to go.