Air Horns for Semi Trucks: A Complete Buyer’s Guide for Drivers

Looking to add some power to your truck’s voice and match your exterior chrome-polished aesthetic? Find the best air horn for your semi truck.

In this guide, we’ll cover the top brands, materials/finishes, mounting options, decibals, sound profiles, and more.

Why Add an Air Horn to Your Big Rig? 

The biggest reason? It adds to your truck's character.

Just like high-pitch whistles or bells, they're a fun accessory to have on your truck.

Air horns and train horns operate by pneumatic pressure sent from your auxilliary air tank.

Your truck's onboard air system can also power other areas of your rig like pneumatic tools, or tire inflation. Typically, drivers will have a dedicated secondary tank just for their air horn. 

Common Types of Horns

Air Horns: louder, shaper sounds for versatile roof-mounted and hood-mounted setups on various vehicles (trucks, tug boats, off-road rigs, RVs, etc.)

Train Horns: multi-bell systems, deepest/loudest sound for maximum presence; typically used off-road, nowhere near residential vehicular traffic (decibel level can cause ear damage). There are also “mini train horns” that take up less space when mounting.

Electric Horn: the everyday car horn that runs on an electric current; this is found in your standard vehicle – and in commercial work trucks including class 8 semis.

Air Horns vs Train Horns

An air horn is NOT a train horn, nor is it a normal city horn. Train horns are far louder.

Typically, you’re not allowed to just blast a train horn on residential roads (unless it’s an emergency), only in rural areas.

Sound Profiles

Dual, triple, quad bell tones offer distinct sound profiles. At different lengths they may have a different tone, but when blasted in unison, they’ll have a more distinct sound.

The material impacts the sound quality and profile. Stainless steel, chrome, ABS plastic, or cast aluminum reflect sound waves differently. 

Mounting Options for Your Air Horn

Common Placements:

• Underneath the catwalk/deck plate
• Behind the sleeper cab (facing back and down)
• Back of the frame/chassis
• Mounted behind the tool and battery boxes to avoid road debris
• Underneath the cab frame - but most of the time it is underneath the sleeper area

Once the air horn sound waves hit the pavement or roadway, the sound waves scatter and product a bigger, badder noise.

That's why a lot of owner-operators choose a frame-mounted, down-facing air horn setup.

There are some guys who like putting their air horn on the back of their sleeper - although this choice is a bit more rare. 

Budget Air Horns & Train Horns (Under $200 Best Buys)

Disclaimer: These are the prices as of 2025 which can and will change over time.

WOLO Black ABS Train Horn (128dB)

Philly Express Train Horn (130dB)

United Pacific 4-Trumpet Mini Train Horn (130dB)

BESTfit Aluminum Small Train Horn *this is a replacement part*

Red powder coated cast aluminum train horn

THIS is what you’d find on a real train! It's the LOUDEST sound you can get but it comes at a premium price ($2k or more).

Core Components of an Air Horn Kit

Want an all-in-one setup? Get a kit. 

Here’s what you get:

• Horns (single, dual, triple, or quad setup)
• Air horn valve & air horn diaphragm
• Air compressor & tank
• Air horn pull chain kit, pull chord, and electric air horn pull switch (driver controls)
• Fittings, wiring, air horn pedestal, truck horn valve stand

Air Horn Parts & Accessories Explained

Air Horn Valve

Air Horn Cover

Air Horn Diaphragm

The diaphragm is what is vibrated by the pressurized air to produce a deep sound.

Air Horn Pedestal

Compressor

Air Tanks

Hoses & Fittings

Mounting Brackets

Solenoid

The solenoid is the electric-run control gate that releases high-pressure air from the pneumatic tank to the horn when the operator switch or pull chord is triggered. They can run off power from your existing air horn if you have more than one set up. 

The Pull Chord

Pull chords also come in different styles too: braided, chained, or otherwise. And if you're running with an air horn toggle switch, you can buy dashboard switch trim for it that will complement any existing interior cover panels or trims you may already have

How to Choose the Right Setup for Your Truck

Look at these two simple factors. 

Fitment: verify the space on your truck’s rail frame, rear cab, or even behind the grille

Sound Preferences: High-pitched air horns vs deeper train horn

Style Design: Choose the finish, material, and the number of horns you want mounted (and their lengths)

Legality of Semi-Truck Air Horns

DOT/FMCSA rules: horn decibel limited to 100-110 dB acceptable range near residential roads/highways. 

Most US states prohibit the train horn use on public roads (except under emergencies).

There's no specific legal distinction between show-truck air horn setups and functional on-the-road horns. 

Another Note: The air horn valve stand, just like anything mounted on the exterior of your truck, has to be properly, securely stationed, otherwise you may get a citation.

Best Styles: Chrome Polished, Powder Coated, and More

Chrome-polished air horns pair perfectly with chrome visors, trim, front-bumpers, and polished stacks. 

Powder coated air horns can give a bold, standout look with a black finish; they also come in various other colors to complement your rig's paint. 

Aluminum cast horns are the most durable and heavy choice. These also come in varied colors - the most common, of course, being black. 

Reinforced plastic air horns aren't too common, but these are still sold. 

Popular Air Horn Brands

Hadley Air Horns

Looking for a straightforward, classic run-of-the-mill single-trumpet setup? Hadley delivers a solid product. Get a 24.5-inch-long chrome-plated air horn with a round bell and squared-off back-end.

BESTfit Air Horns

BESTfit is our long-standing, top-of-the-line aftermarket brand crafted by expert welders and shop designers.

You can opt for a classic, single-setup chrome-polished air horn with a 120dB rating.

Or you can get a multi-trumpet air horn kit with a black powder coated glossy finish.

United Pacific Air Horns

United Pacific is just a powerhouse of a brand – famous for their marker lighting and front fenders; these guys also make outstanding air and train horns. 

Try out their competition series train horn with a 150dB sound output!

HornBlasters Air Horns & Train Horns

Train horn kits with an entire 5-gallon pneumatic tank reservoir with either a 150 or 200 PSI.

Before You Add to Cart: A Quick Buyers Checklist

• Verify truck voltage (12V vs 24V) Confirm the fitment and mounting space (a lot of motor homes have a 24V system, but nearly all big rigs have a 12V)
• Correct size and SKU#
• Balance the price vs reviews/reputation of product
• Check on in-stock availability, shipping details, and the return policy.

Air Horn Installation Tips

Where to mount horns: stick with the roof, frame rail, or bumper.

Do I need a tank? – for real air horns, you will.

How long does a honk sound blast last? - It depends on the size of your air tank.

FAQs

Can I add a horn to my existing air system?

No. Not if it's the primary air system. If it's a secondary unit, go ahead. Some drivers opt for a third or even fourth air system on their rig. 

Do I need a special air horn valve or switch?

You'll need an air horn valve and an attached operator swtich or chord to trigger the release of pressurized air to get a sound. 

Why Every Driver Should Add More Sound to Their Big Rig

Whistles, bells, air horns, or train horns – you name it. Regardless of what you choose, adding some sound to your work truck is just a lot of fun. And it’s relatively affordable – as far as aftermarket semi truck customizations are concerned!