Not that I’m opinionated or anything, but the sound on DCC decoders is just awful. David K. Smith wrote an eloquent piece on this a couple of years back, and I’m going to second and third his motion. There are basically two problems with onboard loco sound: the earbud-sized speakers on the boards aren’t capable of reproducing sound with any kind of fidelity, and even if they could (or even if you piped the sound output of a decoder through a separate amp and speakers), the 8-bit sound digitization on the board is akin to the sound in a plastic child’s toy.
I think it’s easy to get hung up on the idea that a loco’s sound must originate from exactly the same place as the loco, and I’d like to refute this notion. As modelers, we don’t duplicate reality exactly, but rather we design and build heightened and augmented versions of it, with certain things emphasized and other things de-emphasized. Next time you watch a movie, note how the synced sound consists mainly of dialogue and Foley (footsteps, explosions, etc), with much of the sonic environment being “wild” or unsynchronized.
So, what to do if you’re interested in a realistic, high quality, immersive sonic atmosphere for your pike? You can make (if you’re handy with digital audio software and have access to a sound library) or buy a basic environmental sound mix containing country, city, and industrial noises, have these on audio CDs or other playback hardware, and reproduce them through a decent amp, with decent speakers behind or below your layout.
But what about the loco sounds? Time to think outside the box:
- If your layout (or one part of a large layout) is a yard or industrial switching area, augment your environmental sound mix with occasional and random slow-speed loco movements, brake, coupler, bell, and horn sounds, so that the loco you’re controlling becomes just part of a larger sphere of activity. This can be amazingly effective, even though there is no loco “sync sound.”
- If you must have specific sync sound for the loco you’re operating, you could compile a collection of around a dozen key loco sound sequences (station halt, comin’ ‘round the bend, distant and close horn blows, etc) as audio files on a computer. Then use software to trigger these sounds; do this concurrently while you operate the loco. Combine the computer’s sound output with the basic environmental mix, and route this to two good speakers in a stereo pair under the layout, or above it. Again, the overall psychological effect of good, balanced, immersive sound far outweighs being able to have the sound come from a precise location of the layout.
- Don’t use loco sounds, make do with the natural clickety-clack on your model rails.
Finally, note that our ears are much less sensitive to bass and treble at lower volume levels. Your amp (or CD player) may have a “loudness” function, which compensates for this by boosting bass and treble. This keeps the sound fuller without making it louder. Use it if you have it.