The PA output fitted to CB radios has been with us since the first commercial sets went on sale with it now being as much a function we expect to see on a CB radio as a microphone socket or antenna output. Maybe not put to good use as much these days even wiring up a basic PA system in a vehicle can be a good and effective safety feature.
Where to Put the PA Horn and a Look at Quality
Read through enough reviews on PA horns and you start to see a common thread about these type of horns failing to work after getting wet. Mounting the horn under the front grill does give it some protection from water but do plenty of research before “splashing” out on a PA horn and get a quality model that has a good waterproof rating so that your not replacing it after the first downpour.
If you intend to mount any horn outside of a vehicles bodywork on the roof or a cross bar it is completely open to what ever mother nature chooses to throw at it and the task of finding a durable horn becomes even more important.
Take care to run the power and audio input leads for the horn so that they completely avoid any parts of the engine that gets hot also making sure they are fixed down properly.
Although the PA output from a typical CB radio will give a decent amount of volume when put through the right horn don’t expect it to be ear shattering especially if the PA horn is under your vehicles bodywork, it doesn’t matter how powerful a horn is fitted there is only so much power coming out the back of the CB.
With no shortage of audio amplifiers available that work off 12/24 Volt supplies more volume is only a matter of slotting such an amplifier between CB radio and the PA horn. To protect the horn from damage when adding an amplifier into the system make sure it can comfortably handle the extra wattage you are driving into it. Some horn packages will come with powerful slave amplifiers that can easily be hidden away without adding extra clutter to your dashboard.
Using an extra amplifier does give a massive improvement on the basic CB radio PA output with the chance to use bigger horns or even hook up a multiple horn PA system with a very high audio output.
As a bonus there are a few amplifier and horn packages that also throw in a box to generate a wide range of specialized noises to add a bit of kick to your car horn. Try not to get swayed by the chance to have the dukes of hazard horn and buy one of these sets without focusing on the quality of the equipment at the same time.
Photo courtesy of © Superbass / CC-BY-SA-3.0 (via Wikimedia Commons)