By the way, there are very few top-level masters - about 150 people across the globe. But most of them are our compatriots.
What scene are we talking about and what, generally speaking, are the difficulties? The fact is that an ideal sound source is an infinitely small “point” containing both “mid basses” and “tweeters”. That is why there are far fewer problems with “home music” than with “car”: speakers are far from the listener, and therefore their geometric dimensions and the relative position of the speakers do not significantly affect the perception of the musical picture. I sat down in a chair and relaxed: the violin, cello and drums are exactly where they should be: sound images create an imaginary sound stage in front of us. But try moving your chair close to one of the speakers - the scene will “fall apart” immediately! Moreover - instead of music, you will hear the sound of air, the creaks of diffusers … In general, you will immediately want to turn it off.
If in an apartment it is enough to move the chair back into place, then in the car an apartment idyll is impossible by definition. What is the "point" when the speaker - here it is, at the door! And if the "music" was set by an inexperienced amateur radio amateur, then be sure: instead of violas and cymbals, you will hear specific "tweeters" and "midbasses" … But how could it be otherwise: after all, even the dynamics of one channel are scattered in different places! The Cossack choir tries at the level of the knees, and the "ringing of bells" comes from the front windshield. And I don’t want to think about the difference in distances between the right and left channels - one disorder. Slightly leaned back - yeah, there were "bottoms"; came back - again disappeared … And it is very difficult to deal with these problems. But you can!
We begin building the correct sound stage with “tweeters” (they are also “tweeters”). Of course, we are not given to equalize the distance between the right and left “tweeters” - we are not sitting in the center! - however, you can play with the reflected sound and turn them towards the windshield. It reflects the sound well, and therefore this technique is fully justified. In this case, the paths of high-frequency signals will not become the same, but the relative difference between the left and right will significantly decrease. But is it possible to simply drag "tweeters" to the rear window? No, it’s impossible - then our ears clearly localize the source of “bells” from the “back desk”, and this is no good: the sound should be only frontal! In addition, we must not forget that the distance from the ear to the “tweeter” and “midbass” should also be the same if possible.
In the simplest cases, this can be limited. However, modern technology easily allows you to do what a dozen years ago was unrealistic. Today, a self-respecting “head” has the ability to introduce a time-by-channel delay into the audio signal, thereby equalizing the inequality between the dynamics of the left and right channels. It is obvious that in the left-hand drive car the sound of the right channel will always be delayed in relation to the left - in practice this value is up to one and a half milliseconds! So: a smart "head" can delay the "left" signal by the amount set by the installer, and not to the detriment of quality. We enter the menu, “shift” the sound source and display the center of the sound stage at the desired point, equidistant from its borders. And you can adjust the balance a little bit: the delay is a delay, and the right channel needs to be a little added volume: it is farther from the listener!
But what about the reflection from the windshield? Why is it necessary with such a clever “head”? It turns out that you still need to! If you direct the “tweeters” directly to the listener, you can get what we mentioned at the beginning: instead of music, you will hear your own “breathing” of the speakers - creaks, noises, etc. So we carefully unfold the “tweeters” to the glass and … and this is where the installer’s art begins: almost everything keeps on the “tweeters”! The scene may turn out to be narrow, but far, or wide, but close - there will be enough fuss for a long time.
The "cool" headunits like "Pioneer P9R" or "Bremen MP74" allow you to enter delays on all speakers. If the installer manages to build a scene so that when listening you clearly feel five musical instruments evenly spaced around the stage at eye level, then he is well done. But, as we have already said, this is the art of the highest standard: it is not given to everyone.
But what about the "midbass"? Tweeters are relatively easy to move back and forth, but how do you control the location of massive speakers? To redo the podiums ten times on the principle of “a little better, a little worse”? Yes - the beginner has no other way. A seasoned master can also make a mistake, but experience helps him. He feels how to arrange the acoustics in a car with this "figure", and can accurately predict which of the two cars the sound will be better. And he usually guesses the design of the podium the first time - millimeters, degrees and all that.