All I have are older DC or DCC engines. Some of my DC Engines I have converted to DCC, w/sound. There are quite a few MFG where the decoders can be purchased. Requires soldering skills, as 8 to 10 wires are involved. The motor power must go thru the decoder and not direct from the track. Some existing factory wiring has to be changed. Some of the newer engines, I don't have any , I understand, has the 8 or 10 wire decoder that will just plug into a socket already supplied with the engine

Rich
Thanks for reply. The Bachmann Factory DCC and sound has a female disconnect about 2" from the speaker. Over time I have always had a disconnect installed between the speaker and it's board connection. Same as do for Headlites for ease of working. Just don't need the speaker and lite wires tied to the body. I have found out, since my post that the male-female connections vary in size depending on source. I just ordered 10 pair from 'eboot' and they are a different size. from the Bachmann and different from what I have been using. I had believed that the miniature 2 wire connections were industry standard in size and could be mixed.
Not So .

Have the Bachmann DCC diesel that the speaker went bad. Threw it away before I realized the speaker connection on this Bachmann is oversize. I have other speakers, but the speaker connections are loose in the Bachmann fitting. The female socket connection is original factory. I need the oversize male connecting socket. Anyone else aware of this ?