26/12/2024
Everyone has an individual recipe for creating the perfect sound in their vehicle and probably each of us thinks that this is the only proper way. For some, it is the possibility of ultra-precise settings and a multitude of available options, and for others it is the absolute quality of sound that the source is able to provide. Each of them is recognized and each of the methods of implementation can be awarded at international competitions. But does it have to be this way, i.e. one way or another?
In my country, I have often observed discussions between supporters of one or the other of these approaches, they may take different forms, from small jokes and quips to heated disputes and sometimes harsh words.
But is there no other way? Does reality always have to take only such forms?
Having at my hands two pieces of equipment that are (in my opinion) models in their field, being a monument to their creators, I decided to combine them into one organism and give each of them a chance to show their capacities in the area where they perform the best.
The task was radically different from what I had been doing for a large part of my life while trying to individualize the performance according to the needs and wishes of the customers – you can find some of my solutions described in my profile. This time the idea was to use a piece of equipment, namely Alpine PXA-H 900, which for many years has been considered as a reference in sound delivery and – without any modifications to the sound, keeping its reference quality - apply to it the most modern processing possibilities as offered by BRAX DSP – i.e. the digital sound processor which not so long ago elevated the performance standards to the new level.
I liked that idea since the very beginning, it was my own after all, but immediately I realized the challenges lying ahead. When I mention Alpine PXA-H 900 I mean real masterwork – a product designed with fantastic craftsmanship well over twenty years ago but still top-ranked in competitions all over the world.
When you look inside you immediately see that it was made by people who not only knew their job but also liked it very much. You can observe that in design, in engineering, in the ex*****on of individual components. After so many years everything inside seems almost brand new. Real beauty – I think that my opinion in that respect can be shared by all with a taste for high-quality electronics.
The same holds true about the BRAX processor, which is an ideal example of internal architecture planning and is characterized by exemplary order and tidiness. The construction is modular, so it allows for various options of cooperation with external devices, both analogue and digital. In the case discussed here, we use optional digital output cards offered by the producer. My applications make use of the digital output cards, so the equipment is configured for individual use only. Digital communication between devices is based on coaxial transmission, implemented with RCA connectors.
The space inside was very limited so I was aware that messing about with so exquisite workmanship could easily bring disastrous effects, therefore from the very beginning I committed myself to either meet the level of the perfect engineering and come up with the solution that will be worthy of that equipment which fills me with admiration or not to do it at all.
What I wanted – and finally hope was able – to achieve was to make the best use of the very limited space available, maintain the modular arrangement as originally made, adapt the board as inconspicuously as possible and optimise the connections.
The presented location of the necessary electronics ultimately helped me to reach the first mentioned above objective, i.e. to stay in the same modular layout. The second aspect was to radically shorten the length of the connections, which has a direct impact on the transfer of this type of signal.
In fact, there is one visible mark of my operation inside, i.e. there are 4 cables for connection to the coaxial sockets.
The equipment does not show any signs of external interference, and the visible set of sockets consists of 4 digital signal inputs (coax - RCA) and 8 analogue RCA signal outputs.
As mentioned before, beside delivering the high fidelity sound, without any modifications, my idea was to maintain all the possibilities offered by the original equipment.
Alpine uses a separate analogue output level control. This applies to both the main level control and the individual level setting for each of the available channels (0 to -12dB). This in turn means that the D/A converter always works in the maximum dynamic range in each of the variants. I was happy to be able to keep subgroups, balance, fader, subwoofer control.
The equipment can be controlled both with the original remote control and with any Alpine unit equipped with the Ai-Net bus. Active memory of the settings provides possibility to store 6 variants of these settings.
In the attached photos I tried to present the effects of the work, which included all aspects from the idea, electrical design, planning and ex*****on of the planned activities. But there was one thing left that I was not able to do on my own.
To present you this report in a clear and legible form in English. And for that I would like to sincerely thank my old friend Witek Kurylak. Heartfelt thanks to you, Wiciu!
