it takes more energy to get high db and low tone. that’s why most of the air horns you see by way of kits don’t have the impressive train horn db ratings.
The tone on the marcos is not quite baritone; it’s deeper than the stock, anemic horn, and louder, but it lacks that basso profundo. It’s not a high pitched squeal. Worth the money IMO.
FWIW, I also swapped compressors to the Wolo, but the Marco compressors made better db, so swapped them back. If you get a 2nd kit, keep in mind the Marco uses 2x direct drive compressors at 20a circuits each. You might as well get a train horn for that draw ;-)
If I did do a 2nd kit, I’d get a different set of trumpets; smaller, higher pitch and a bigger trumpet like the horn blasters direct drive - ninja and I don’t remember the other. That might be a good complement. If I could get up to about 122-125 db, I think that would be a happy medium between getting enough volume to make a cell yakker put down the phone and pay attention vs. the space taken up by a train horn.
OTOH... train horn kit can also double as on board air.