Most of the driver’s car is more than a vehicle. Sometimes people spend hours in the car every day and listens to the news radio broadcast and listens to music. Having good quality music sound in the car requires more than good speakers and power amps, but some smart solutions are also needed to make it sound better.
There are plenty of publications on how to DIY a good car sound system at home in the current time. Even the best power amplifier does not guarantee that car music will sound like Hi-Fi class. The main problem is the hard installation of the audio-system inside the vehicle. In many cases, speakers are installed where ever they fit in the car. But there is also no clear answer where it is the best place to install speakers and how. The most common mistake is to place powerful high-quality speakers in the rear shelf while the speaker’s front position is installed or not at all. Such an audio system installation gives a feeling like he is sitting back to the scene.
First of all, it is important to keep in mind that the purpose should be not to install a more powerful audio system with poor characteristics but to install an audio system with wide dynamic characteristics for listeners who sit in front seats of the car. So the first solution of this is to install dynamics in the proper front place.
It is ideal when the distance to the left and right speaker is at the same distance from the listener. It is not always to do this because the driver and passenger sit in the right or the left side of the car. But it can be done with sound full or partial reflections from the front window as in drawing above.
To construct such an audio system may look like a tricky task, but results pay off. Not many will dare to cut car floor to install speakers, so speakers are placed inside doors and panels in reality speakers.
Car panels allow to install speakers in quite a high position, but speaker diameter is limited to 10…13cm. Such speakers are not capable of covering the dynamic range of music sound. Typically low-frequency sound is missing very high frequency as well. Small dynamics of high freq may be placed on front window stands.
Low frequency and coaxial speakers usually are placed in the car doors because doors have some closed volume. But investigation shows that results aren’t as good as expected. The fact is that when music is recorded, low-frequency instruments are usually placed in the center of the orchestra and other music signals on left and right. But when low-frequency basses are inside doors, 100…150Hz phases attack each other in the middle of the car, and the quality of sound drops. When dynamics are placed in the lower panel, the sound is better, but the sound picture is too low, and it seems that you are listening to music from above.
According to upper discussions, we can conclude that the best result may be reached when music sound frequency bands are separated and seeded in the car’s front position. Narrowband speakers should be placed in such positions so they could be most effective. One good low-frequency speaker placing is under front seats with directions up—middle frequencies in the door’s front panel or upper position. And high frequencies should be placed on side front window holders â€“ so that sound could directly reach the ear.
To get full bass 100…120Hz or even below require speakers with quite big dimensions. If not subwoofer used, then the lowest frequencies are limited to 100…120Hz. If you need lower, then the subwoofer is needed. Usually, the subwoofer is placed in a car trunk. It is good to have the ability to adjust subwoofer frequency characteristics because each car salon has different characteristics.
To get a good sound depth, there also a center channel used in-car audio systems. Center channel power should be no more than 10% of overall system power. The signal can be taken from the left-right channel or sum or difference or even combination. The Center channel usually is connected through a filter:
There are many discussions about cables used in audio systems. One important general rule is that voltage drop on a cable shouldn’t exceed 0.1…0.2V.
Damping the spurious resonance of sound elements is also important and improves the quality of overall sound. Damping material should be used in all places where speakers are installed. Especially take care of panels. Resonance usually disappears when the surface area is 25% covered with dumping material. Also, don’t forget about the road noises. If you want outstanding quality, you should cover the salon floor with sound resistant material – especially where tire areas are.
Original source: https://cxem.net