Train Truck Air Horn Kits are an easy way to let other drivers know your there. They add style as well as a great amount of functionality and safety to your custom aftermarket automobile. In one way or another all train / truck air horns and the way they work are very similar to each other. If you see much alterations from one horn to another, it would most likely consist of the air management hardware used and possibly the horn style and size. The concept of harnessing this equipment to create the horn noise itself is very much the same.

Train Truck Air Horn Document
Basic Air Horn Equipment Diagram

The basic train / truck air horn systems work by harnessing a pre-compressed volume of air from the tank of an air management system which is initially compressed utilizing a tank and compressor combination. This pneumatic system of components to compress air and store a set pressurized volume of air can be ready to blow air at a moments notice. Once the air management system is established and then valved to the air horn, a complete system is now in place. There are a few components of the air horn air supply that we will not elaborate on at the moment, but we know once the air pressure is released through that valve the horn sounds. In some cases the compressor may be directly connected to the horn which would require an efficient match of compressor air output to air horn input. This type of system needs to be perfectly matched to ensure the appropriate amount of air travels through the horn to make a noise. Much of the horns amplitude is based off of the size of the horn orifice, the size of the airline, size of the air valve and the amount of pressure you are pushing through the entire assembly and out through the air horn bellows. An air horn works the same way a musical instrument works in a orchestra. For a visual schematic or diagram on how all this equipment does together, check out the image above.
The actual air horn itself can be refereed to as the heart of the system.  These interesting units work by using stored pressurized air to vibrate a single or multiple diaphragms located at the very end of the air horn bellow within a resonating chamber. This chamber is built to become pressurized and release noise very quickly. When the horn is activated and air travels from the air management system through the open air valve to the horns resonating chamber and then escapes the horn through the bellow. This quick transfer of air from the valve, compression chamber to ozone is what promotes vibration at the diaphragm which in turn makes your loud air horn noise..The bellow of the horn tapering from small to large at the mouth is the main reason for the amplitude of the noise being emitted, as this transfer of noise thought the slowing increasing size of the bellow helps amplify the vibrating diaphragm.