correct until the supply pressure drops below 150. but be warned, the regulator will also limit the volume of AIrflow as well and decrease the sound of the horns. the Shocker XL uses a 1/2" Main feeder with 1/4" lines to each bell of the horn. the OBA setup only has 1/4" ports so it will be a choke point in the system.
I have a similar kit on my truck. Viair 380C compressor, 5 gallon tank, and the Shocker XL. I have been running the full 200 PSI through my horn for the post 2 years without issue. every now and then with such a high pressure i do get s slight high pitch squeak from the horns before the well known deep Honk sound but it is rare. and on only a 2.5 gallon tank you will blow through that amount of air in no time with the Shocker. a few short blast will easily drop you down in air pressure considerably.
1998 ZJ-- lowered a touch
2005 GMC 2500HD 496 C.I.
Fat Amy-1989 K5 blazer. Linked, lifted, 38.5's on won tons. Big Girls can play in the woods too.