Sorry, I just saw this
The newest MTH bigboy that I got, has the MTH wireless drawbar on it. All my others (older models) have the wired tether.
In G scale, the board is in the engine. The speaker still is in the tender. I wish they would add a speaker in the engine. Our grandson asked when he was younger, "why does the sound come from the tender?"
even if they just put a tweeter in the engine, I believe it would help with the illusion...