Grover 1510 Airhorns: Direct Drive vs. Air Tank
I'm working on sorting out some specs for an emergency vehicle we're planning on installing an airhorn on. The vehicle doesn't already have a compressor on it (no airbrakes).
I called Grover to ask about their opinion on the matter. They suggested using their "1507 Kit", which has a 1510 horn and a 1556 direct-drive compressor at 25 psi. The alternative is to install a 130 psi compressor with 5-gallon air tank. They said that the direct-drive is nicer because there are no concerns with it ever running out of air from continuous blasts.
My concern is with the quality of the sound and the volume. Obviously, 25 psi from the direct drive is much lower than the 130 psi from the tank, which I would expect to have a very significant difference in tone and volume. Do any of you have experience with the direct-drive systems?