I use the MRC 2 speaker sound system. I bought it when it was about $31.95. It's the earlier version of the Symphony 77. There's about 30 diff. sounds. I have 1 of my speakers in a 5 gal. plastic bucket facing toward the back of the layout & the other speaker is under the control panel. When the train is far away from me I turn the sound down so you can barely hear it & then as it gets closer I turn it back up. There's 2 diff. diesel horns, 2 diff. steam horns, bells, uncoupler noise, brakes, crossing bells, all aboard & others. I let visitors operate the sounds while I run all 4 trains.
Larry