Many car enthusiasts, especially those who are actively interested in tuning or often drive on highways, ask the question: why do they put a horn in a car? At first glance, this may seem like a simple desire to stand out or create more noise, but there are quite utilitarian reasons for installing such signals.
The main purpose of replacing the standard “piler” with a powerful system is to increase safety by increasing the volume and range of the sound signal. In situations where it is necessary to urgently warn other road users about danger, the standard city horn often turns out to be too quiet and ineffective.
In addition, the horn system is capable of operating at extremely low temperatures, where conventional membrane signals would simply freeze or become ineffective. Let's take a closer look at what problems this element solves and whether the game is worth the candle.
Main function: safety and attention-grabbing
The main reason why owners decide to install air signal, lies in the need to be heard at a great distance. Standard car horns typically have a volume level of about 105–110 dB, which is quite sufficient for an urban environment, but ineffective on an open highway or in strong headwind conditions.
Horn systems powered by a compressor are capable of producing sound up to 150–180 dB. It's not just louder, it's a fundamentally different level of perception. The sound of the horn has a lower frequency and high penetration power, which allows the van driver or truck driver, who is in the cab with the windows closed and the engine running, to hear the warning.
However, it is worth remembering that the use of excessively loud signals in residential areas or at night may be considered a violation of traffic rules and silence regulations. Horn installation is a tool that requires responsibility and understanding of the context of its use.
⚠️ Attention: Installing signals louder than 120 dB can lead to problems when passing a technical inspection and fines for making changes to the design of the vehicle that are not approved by the traffic police.
Operating principle and system design
Unlike electric tweeters, where sound is created by vibration of a metal membrane under the influence of an electromagnet, the horn system is more complex. The basis here is pneumatic signal, which produces sound due to the passage of compressed air through special valves and sockets.
The key element of the entire system is the compressor. It forces air into the receiver (tank), creating the necessary pressure. When the driver presses the signal button, the valve opens and compressed air with a characteristic whistle rushes into the bells, forming a powerful sound stream.
There are also electric horns that imitate the sound of pneumatics, but operate from an on-board 12 or 24 volt network without the use of a compressor or tank. They are easier to install, but are inferior to full-fledged pneumatic systems in the duration of a continuous signal and sound timbre.
The design of the bells also plays an important role. The shape and length of each horn determines the frequency of the sound. Usually a set of several bells (often three or five) is installed, tuned to different notes, which creates that very recognizable chord that cannot be confused with anything else.
Advantages over standard signals
Why are drivers willing to spend money and time on installing a complex system? The answer lies in a number of undeniable advantages that the use of pneumatic signals compared to standard electric counterparts.
Firstly, it is reliability in extreme conditions. Membrane signals often become clogged with dirt, water and snow, causing them to fail. A pneumatic system, especially with properly installed moisture separators, is much more resistant to aggressive external environments.
Secondly, durability. High-quality brass or chrome-plated bells and reliable compressors can last for years without loss of performance, while ordinary horns often burn out or lose volume after 2-3 years of use.
- 🔊 High Volume: The sound can be heard for several kilometers, which is critical on the highway.
- ❄️ Frost resistance: The system works effectively even at temperatures below -40°C, when vehicle batteries are discharged and electrical signals are weak.
- 🎼 Unique timbre: Ability to customize the sound to your preferences (from low bass to high squeal).
Types of car horns
The car audio market offers many options, and choosing the right one can be difficult. All systems can be divided into two large categories: electric (imitation) and full pneumatic.
Electric horns such as popular models Hella or Bosch "Retrofit" series, they look like bells, but inside they have an electromagnetic mechanism. They connect directly to the car's standard wiring, without requiring the installation of a compressor and cylinder. This is an ideal option for those who want to improve their sound, but are not ready for complex tuning.
Pneumatic systems are divided by type of compressor (piston, membrane, screw) and number of bells. The most common are “triple” and “quintuple” sets. There is also a division by timbre: bass signals for trucks and SUVs, and high-frequency signals for passenger cars.
Separately, it is worth mentioning horns (klaxon) - historical mechanical signals, which are now used more as an element of retro tuning, but are still found on the roads.
How to distinguish a high-quality horn from a cheap one?
Pay attention to the material. Cheap models are often made of thin plastic or silumin, which bursts in the cold. High-quality bells are made of brass, stainless steel or high-quality ABS plastic with chrome plating. The weight of the compressor is also important: lightweight aluminum models heat up faster and fail compared to cast iron or steel counterparts.
Comparison of characteristics of different systems
To finally make a choice, it is necessary to compare the technical parameters of different types of signals. The table below will help you understand the difference between standard equipment, electric horns and full-fledged pneumatics.
| Parameter | Standard signal | Electric horn | Pneumatic system |
|---|---|---|---|
| Volume (dB) | 105-110 | 115-125 | 130-180 |
| Current consumption | Low (5-10 A) | Average (10-15 A) | High (compressor 10-20 A) |
| Difficulty of installation | Minimum | Average | High (requires space for tank) |
| Job resource | 3-5 years | 5-7 years | 10+ years |
As can be seen from the table, pneumatics win in all respects except ease of installation. However, for everyday city driving, an electric horn can be a happy medium, providing good sound without having to redo the trunk floor.
When choosing a pneumatic system, pay attention to the performance of the compressor. For three horns, a compressor with a capacity of 120-150 l/min is sufficient, and for five or more it is better to take models from 200 l/min so that the sound is dense and does not “choke”.
Nuances of installation and maintenance
Installing a horn system is not just a matter of “screwing it and forgetting it.” This is a set of works that requires an understanding of the basics of auto electrics and pneumatics. Improper installation can lead to failure of the vehicle's electrical wiring or even a fire.
The first step is to ensure reliable power supply. The compressor consumes significant current, so it necessarily must be connected via a separate relay and fuse, directly from the battery, using a cable with a cross-section of at least 2.5 mm². Standard signal wiring simply cannot withstand such a load.
The second important point is protection from moisture. The air, compressed in the compressor, heats up and then cools in the receiver, which leads to the formation of condensation. If water is not removed, it will get into the pipes, and in winter the system will freeze, turning into ice.
- 💧 Water separator: A mandatory element installed between the compressor and the receiver or in front of the bells.
- 🔋 Relay and fuse: Protect wiring from overheating and short circuit.
- 🔧 Mount: The sockets should be directed downwards or to the side so that water does not flow inside, and secured with a vibration decoupler so that they do not rattle.
⚠️ Attention: Never connect the compressor directly to the horn button in the car. The current drawn by the compressor motor will instantly melt the button contacts and may damage the wiring. Use only relays!
☑️ Check after installation
Legal aspects and culture of use
Installing additional equipment always borders on the law. In most countries, including the Russian Federation, changes to the design of a vehicle that affect safety must be agreed upon. Although replacing a signal rarely becomes a reason for an inspector to stop; formally, the use of devices that emit special sound signals (sirens, strobes) is prohibited for civilians.
However, ordinary pneumatic horns that do not imitate special police or ambulance signals are, as a rule, permitted if their volume does not exceed established standards (usually 120 dB). Problems can arise if your signal sounds like a multi-stage siren or produces unlicensed sound effects.
The culture of use is also important. The horn is designed to prevent emergency situations on the highway, and not to greet friends at the entrance. Uncontrolled “humming” in residential areas irritates others and creates a negative image of the driver.
A responsible driver uses a strong signal only when it is really necessary for safety, realizing that his actions are heard by hundreds of people around.
Can I get a fine for installing a horn?
Yes, theoretically it is possible. If during the inspection it is revealed that the noise level exceeds the permissible standards (more than 120 dB according to GOST 8769-75) or the signal produces the sounds of special signals, the inspector has the right to issue a fine for making changes to the design or violating the rules for using external lighting devices and sound signals.
Do I need to change the wiring to install an electric horn?
In most cases, standard wiring is not enough. Even electric horns consume more current than regular tweeters. It is recommended to run a separate wire from the battery through the relay. If you leave the standard wiring, it can heat up, and the contacts in the connectors can oxidize and burn out.
How often should water be drained from the pneumatic system?
The frequency depends on air humidity and intensity of use. On average, it is recommended to check the dehumidifier and drain the condensate once every 1-2 months, and before the onset of winter cold it is mandatory. If this is not done, the water will freeze inside the system and block the air supply.
Is the horn suitable for a car with a small engine?
Yes, it will do. Modern electric horns or compact pneumatic systems with small compressors do not have a critical effect on the operation of a passenger car generator. The main thing is the correct connection diagram through the relay, so as not to overload the standard circuits.