Steve, at the time i put the Loksound decoder in my F-E-F, i was buying them at Tony's trains. since then though, i have found Loksound decoders on sale at different places on the net

. Tony's has EXCELLENT service, but not always the cheapest.
if you decide to go with Loksound, like i said before, it IS A REAL TIGHT FIT, but do able

. i took the whole top part of the shell off to run the speaker wires to the cab. i made a small styrene "box" to put the speaker in to make the sound louder

, painted it black, and placed it in the cab. if i wasn't so lazy

ops:, i would have made the speaker wires longer, and ran them into the tender. by doing that, i could have used 2 larger speakers, and got better sound

.
i would check the size of the Tsunami, and Loksound decoders, the smaller of the to would make life a lot easier, just my thoughts.
EDIT, UPDATE: MRC's NEW steam sound decoders ARE NOW OUT! i know for a fact that these ARE narrower then Loksounds, and the Tsunami, might be something to consider.

-Deano