Coaxial speakers when used in a car audio system have the advantage that they produce a wider range of frequencies from one unit only. A coaxial speaker has the ability to produce low frequency sounds for bass and higher frequencies produced by the tweeter. This is in addition to the Mid-range frequencies.
Normally a coaxial loudspeaker has a tweeter in front of the woofer in a two way coaxial speaker. Three way coaxial speakers have a Tweeter and midrange speakers in front of the bigger and usually oval in shape bass cone. The bass diaphragm is usually partly obstructed by the speaker system mounted in front.
The problems comes when doing an aftermarket car audio upgrade for you vehicle. Some installers usually install these systems facing upwards at the back of the saloon vehicle. These speakers are usually receiving large amounts of sunshine during sunny days. This is the wrong way to install such type of speakers. Why?
Let us examine coaxial speakers; they usually have the tweeter suspended from the central iron that encloses the woofer voice coil. So there is a gap all the way down that exposes the coil.
When a coaxial speaker is installed horizontally, gravity makes dust particles settle in the voice coil. Biscuit fragments also find their way down the speaker aided by the steep slanting bass producing diaphragm. Water also finds its way inside the coil very easily, when cleaning the vehicle.
This gap can hold dust and other particles, thus distorting the clear and quality sound that the Amplifier or Head unit is providing to your speakers. Nevertheless, the friction these dust and biscuit particles have when the speaker diaphragm is moving further damages the coil.
Car stock coaxial speakers usually come installed vertically in the doors, why should you install them horizontally just to damage them in the long run.
But there is a way you can install coaxial speakers horizontally but only if they are installed facing downwards like the featured image I took of a coaxial speaker in a Kenya Mpya bus that plies the Thika Nairobi Route.