I have a GS4 4-8-4 model no. 50201, DCC on board.  To add sound, I assume I can do so by (a) opening the tender and removing the 8 pin male plug and the attached factory decoder from the circuit board, (b) replacing it with an 8 pin to 9 pin converter which then attaches to a motor and sound decoder and (c) placing the speaker under the existing circuit board.  Also, I assume the magnet side of the speaker is up and cone down.  Am I missing something?

I recently purchased a 4-8-2 light Mountain, DCC ready, on eBay.   It came with a DH120 decoder installed although the description said no DCC.  It ran slow and noisy but after lubricating it is up to speed and less noisy. The firebox is illuminated constantly, independently of the headlight.  Is there a way to make it flicker or turn it off?

In this DDC on board Consolidation, what is the status of the tender re adding sound?  Are their holes for a speaker?  What sound unit is recommended.