No, they don't. the 9 pin is there for 9 pin decoders, not sound. Loksound decoders for example run on the 8-pin plugs. the problem here is speaker installation. Nowhere in the Athearn is there a good place for any of the aftermarket sound systems unless you modify it. some might be easier than others, like an F unit has lots of space for a speaker, while your Athearn GP40-2 or U-boat will have a tough time squeezing the speaker in anywhere. Sure, you can get a smaller speaker, but sound quality will go down. the horrible thing with the atlas is that they made the weights so that you could mount 2 large speakers in an A frame over the drive shaft, and in the silver series they replace the speakers with round weights. If the QSI decoder was available, it would be easy to plug the decoder in and attach the speakers. Loksound decoders require the afforementioned pressure chambers that take up alot of room, and i'm not entirely sure the metal clip thing can apply the right kind of pressure to the speaker. The other sound decoder Manufactuerers don't even make sounds for my B40-8, so they are done to. these people need to start selling thinner speakers so that they can fit in the tight spaces of the locomotives.