Every modern car comes with a “stock” audio system that the manufacturer decided was an adequate sound package for that particular vehicle. However, people who love listening to music in their cars or simply like to modify their vehicles will often seek aftermarket car speakers and audio units to make the sound louder and of better quality. When installing a new system, it’s important to know the facts.
Speakers should be placed to get the maximum sound quality. Thus, imaging is important. Imaging is strategically deciding which sounds will come from which places. In most cases, the vocals of the music will come from the units in the center of the car. Melodic instruments, on the other hand, normally come from the sides of the vehicle. Having the same sound come from different places in the car will lessen the sound quality.
Staging goes hand-in-hand with imaging. It helps to make the music sound similar to that of a concert. It should sound like the singer is standing up front while the bass and guitar are coming from behind the vocalist. They should all seem to be coming from the front, though technically they are coming from all over. Essentially, the placement of the speakers and what comes from where will “fool” your brain.
As if imaging and staging aren’t difficult enough to master, one must then get proper directivity. It is related to the science of frequency – by overlapping middle and low frequencies, directivity will “bring” sounds to the front. Midbases should be played as low as possible without getting distortion while subs should be at a higher frequency. The bass coming from the front and back will then be mixed, making it seem as though the bass is coming from the front.
There are several different types of speakers. Coaxials, or three-ways, are two or more units built in the same frame. They are inexpensive and easy to install. Separate speakers are tweeters, woofers, and an external crossover which can be used experimentally for perfect staging. Horns are a type of speaker that are great for directing sound and are very efficient. Midbases and subwoofers add to the low frequencies of the system.
It is best to mount them in the front of the car to give the best sound while reducing the delay. Rear speakers should be used to create a sense of depth in the music, but should definitely not overpower the directness of the front units. Center channels, in addition, help give the sense that the vocals are coming from the front of the car. They are subtle and should never be too loud – they are simply for spacing purposes.
There is in fact an exact science to installing car speakers. It relies heavily on the physics of sound to give the best quality. If they are not placed correctly or if the imaging is off, it will sound like the voices and instruments are coming from all over the place and will sound low-quality and unrealistic. The idea is to get the music sounding as much like a concert as possible, and it will probably require the help of a professional to do so.