I picked up a great set of triple horns for my rig from Siege Engineering, 3 gallon 250psi tank, 1/2 inch lines, extreme pressure release valve, monster 40mm compressor, relays, switch's, fittings and more for $600.00. Running larger lines will allow you to move alot more air and get a bigger blast from your horns without bringing the heat and wrecking your compressor. This is how a train horn is supposed to sound....CRANK UP YOUR PC SPEAKERS AND LISTEN...
http://www.siegeengine.com/auctions/horn/horn.mpg
http://cgi.ebay.com/Train-Horn-Triple-Air-Horns-GOLD-PLATE_W0QQitemZ130039593546QQihZ003QQcategoryZ1493 2QQtcZphotoQQcmdZViewItem
