From DSR to DSP

 

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After the advent of the 7 series speakers with the DSR, The ESB engineers began to think about the next step in sonic accuracy. We determined that this step would be to overcome the last obstacles. First we need to create a larger sound stage over a wider listening area, then we need to get the correct pairing of each speaker to the particular environment it is placed in. Until then, indeed up to now, the problems are still unsolved and the solution is that of trial and error by changing the position of the speakers and intervening with corrective, mostly very expensive, measures for the treatment of the environment. Measures that often still end with an unsatisfactory result. Obviously the question is complex and the intervention must be made in the two directions which are: 1) Adapting the speakers to the environment first, and, as much as possible; 2) Adapting the environment to the particular characteristics of the speaker.

 

Now it's clear that the speaker manufacturer can act only on the first point. So the ESB goal was to change the behavior of the speakers, correcting level, phase and delay, in an effort to offset environmental anomalies. The level is like what happens in modern headphones with noise cancellation (it produces a sound identical to the one you want to delete, but in phase opposition with a result of zero noise). This is an phase’s correction of 180 degrees. In the loudspeaker, fixing the level of opposite sign to the excessive frequencies detected in the environment can lead to obtain a linear response curve. Also adjustments of levels and delays are just as effective to eliminate or correct unwanted reflections and standing waves of certain frequencies... but, as we have said, the situation is complex and never solved 100%. But to do all that the speaker can to solve these problems is the responsibility of each speaker company. So the ESB had set this goal. With all the necessary considerations on the matter, the project was abandoned, at the time, because it was certain that the complexity of analysis and calculations to arrive at correct levels, phase and delay of the speakers demanded technologies (signal processors) that were not available then except for expensive professional applications, and not practical for the consumer market. 

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A few years later, in early 2000, this technology become available with ever more powerful processors that, thanks to algorithms and software (and firmware) equally advanced, could solve many problems of acoustics, first in professional solutions and eventually in the consumer market. To the point that for the sound of the cramped cockpits of the cars, it is applied more and more massively up to the present date (late 2015), and now seems to be the only way to install car speakers quickly and have satisfactory results. Satisfactory but not extraordinary. Unlimited crossover choices (choice of frequency of use of each single loudspeaker), equalization of frequency response, signal delay and phase control  all combine to give good sound at one location...but only at one location. Always a "single point of listening", as was the 'sweet spot" of home acoustic scene, before the arrival of the 7 series with the DSR speaker array. But at least with the correct digital processing you had good sound at that spot, with the only sound system adjustments and without any change to the car environment. You can still argue that one sweet spot in the car is not enough, because  there are at least four points to meet, but a good result was reached. So was born the DSP (Digital Signal Processor).

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Now the ESB research resumes with the goal of combining DSP with the concept of a DSR array to create an electro-acoustic system that will achieve concert sound in a vehicle at all four listening positions. It will be possible? Well, we shall see... Obviously what you succeed in achieving in the car will have value in any other environment as well, because we are only acting on the electronics and speakers, but not on the environment in which the audio system is placed. We would say also that to achieve this result will require electronic engineers and acoustic engineers working together on the one project. As this has not happened often in the world of HiFi, perhaps we could say it's time. We believe that the proper marriage of high-end amplifiers and new digital processing technology and high-end speakers can develop a truly exceptional audio experience.