Best Air Horns for Trucks

Buying guide for best air horns for trucks

With roughly a quarter billion licensed drivers in the US, American roads have never been more crowded. To make matters worse, drivers are more distracted than ever. Studies have shown that distracted driving – especially as a result of cell phone use – is as dangerous as driving while under the influence of drugs or alcohol. And cell phones aren’t the only danger: radios, kids, GPS devices, and conversations can all contribute to distracted driving.

While distracted driving is dangerous in any situation, it’s especially dangerous when large trucks are on the road. Fully loaded, a semi can weigh as much as 40 tons, making it difficult for a truck driver to avoid a last-minute, tragic situation. Even worse, semis are much louder than the average passenger vehicle, making it harder for a trucker to get the attention of and alert other drivers. Because of these factors, many truck drivers use air horns rather than standard vehicle horns. Air horns are much louder and have distinctive tones that stand out in the noise of traffic.

If you’re in the market for an air horn, we can help. Our shopping guide and recommended products can point you in the right direction.

Multi-trumpet, train-style air horns were originally created to help people differentiate the sound of a train horn from a standard truck horn. Early diesel locomotives had horns that sounded too much like truck horns, resulting in a number of tragedies and prompting the change.

Key considerations

There are a number of factors to consider, both practical and legal, when choosing an air horn.

Number of horns

Many air horns use multiple horns, also called chimes or trumpets, to create their distinctive depth of sound. Each horn produces a different note that, when combined with the others, creates a chord. Air horns can have anywhere from one to five trumpets, producing a wide range of sounds. Many modern air horns include filters to help keep dirt, debris, and humidity out of the trumpets.

Internal vs. external compressor

Because air horns are powered by compressed air, they have to be hooked up to an air compressor to function. Smaller units come with a small internal air compressor for ease of installation, while more powerful units tap into the air compressor that powers the truck’s air brakes.

Decibels

Another thing to consider when shopping for an air horn is the noise level. Depending on the number of individual chimes, as well as whether it uses an internal or external compressor, air horns can produce sounds in the range of 110 to 150 decibels (dB). As a comparison, a lawn mower produces approximately 100 dB. It’s believed that a sustained noise level of 85 dB can cause hearing loss over time.

Train vs. truck

Trains use a larger, more powerful air horn to create the unique chords that locomotives are known for. As a result, train horns also produce more sound, usually in the range of 175 decibels.

Legality

Because of the loudness of the sound an air horn produces, many states have passed laws to limit the circumstances in which an air horn can be used. For example, in many states it’s only legal to use an air horn to give a warning. Any other use can result in significant fines. Many states and communities have laws prohibiting their use in population centers. Check your local regulations before you buy.

Air horn features

Air horns have a number of features you should consider depending on how you plan to use it.

Sealed vs. non-sealed

Many air horn systems have compressors and air tanks that are designed to be stored inside the vehicle, safe from dirt, debris, and weather. Storing the system outside, somewhere on the chassis, will significantly shorten its life as dirt and water make their way into the compressor and damage it. If you need to install the compressor and tank on the outside of the vehicle, look for a sealed system. While more expensive, these units are designed to withstand outdoor conditions and will last much longer.

Activation

Many air horns are operated by pulling on a ceiling-mounted cord to open the valve and supply the horn with the necessary air to sound off. More modern systems have a button on the steering wheel like any other vehicle. In an emergency situation, the steering wheel button may provide faster response time.

Horn volume and duration

The factors that impact the loudness of a horn and long it will sound are air pressure, air tank capacity, and duty cycle.

Air pressure: As a general rule, the higher the air pressure, the louder the volume.

Air tank capacity: A system’s air tank capacity impacts how long you can blow the horn. For example, a one-gallon tank at 150 pounds per square inch (psi) produces four to five seconds of sound.

Duty cycle: Similarly, the duty cycle of the air compressor tells you how long it can be used before it needs to rest, based on a 60-minute cycle. A compressor with a 10% duty cycle is able to run nonstop for six minutes before resting for 54 minutes. The longer the duty cycle, the longer you can blow the horn nonstop.

Air horn prices

Because of the range of features and options, air horns vary significantly in price.

Inexpensive: Models that cost $50 or less are the most basic air horns on the market and focus on compactness over quality and sound. These horns have a single trumpet and are often small enough to be installed on cars and motorcycles in addition to trucks.

Mid-range: Air horns that cost between $50 and $100 represent a big step up in quality and sound. Many of these horns are advertised as train horns but are designed to be installed in a truck. Virtually all the products in this category include multiple trumpets and heavy-duty components designed to last.

Expensive: The air horns that cost between $100 and $500 are the best of the best. Horns in this category have multiple trumpets, sometimes as many as five. They’re made from the highest-quality, anticorrosive materials and are designed to operate under the harshest conditions. They also produce the richest, loudest sound.

Tips

• Never sound an air horn in a residential area. Many air horns produce sound in the 150 dB range. Even momentary exposure to that level of sound can result in permanent hearing loss.
• Position the trumpets at a slight downward angle. This will help prevent water from collecting in them.
• Check the compressor. If you plan to connect your air horn to a compressor system that’s used for other things, make sure the compressor is a 100% duty cycle compressor. This will allow it to run nonstop without resting.
• Look for ABS plastic. When shopping for an air horn with plastic trumpets, make sure the plastic is ABS. This kind of plastic is very durable and relatively close to metal in overall quality.

Other products we considered

In addition to the products we reviewed, there are a couple of other options that may work well for you. The Hurbo Super Loud Train Horns Kit is a four-trumpet air horn system producing 150 decibels of sound. It includes a 1.59-gallon air tank and pumps up to 120 psi. The tank and compressor are waterproof, making this a good option for exterior mounting. The Stebel Nautilus Compact Air Horn is an excellent, low-priced option. This horn is compact and works with any 12-volt system, making it ideal for installation on virtually any vehicle. It also produces a two-tone note, giving it a richer sound than many horns in its category.

Trumpets can be made of either metal or high-grade plastic. Metal trumpets may be slightly louder and produce sound that resonates after the blast. Plastic is less expensive and less prone to dings and dents if mounted underneath the truck.

FAQ

Q. Are train air horns legal to use in a truck?
A. Yes, with caveats. Some states have laws prohibiting the use of train horns as a warning system and only allow them to be used as part of an anti-theft system. At least one state requires certification and only allows a train horn if it’s hooked up and powered by the air brake system. Other states allow them as a warning system as long as they aren’t used frivolously.

Q. How expensive are the fines for noise pollution or blowing the horn excessively?
A. Fines can vary from $75 to $1,000, depending on the state.

Q. Can I install an air horn kit myself?
A. Yes, in most cases. Air horn kits come with everything you need to install them, including instructions. As long as you’re comfortable working with 12-volt systems, you should be able to install it.