Hello!
I have just installed a Tsunami sound decoder into my Csx MP15AC and need some info.
What airhorn is proto?
I looked up on railpictures.net and found some 5 chime–probably Nathan. There looked to be a few 3 chime. I would check out your unit number on a place like railpictures.net or similar and first find out how many chimes(individual horns) it has first Your model may not match the prototype in that regard so you may need to get the appropriate replacement.
Once that’s done, due to the sound quality and frequency spectrum differences per installation I usually try to get a video of the unit or similar in action to hear what the horn sounds like and then pick the closest match to my ear. Tsunami is great on being able to change sound by adjusting the equalizer too. This is when I like using Decoder Pro from jmri.
Richard