WORDS & PHOTOS 'DR' AUDIO' MR KHO

Head Unit A unit of Pioneer DEH-P9450MP single-disc player replaces the stock head-unit. The DEH-P9450MP was chosen due to its multi equipped features such as a Digital X-Over Network, a 13-band Digital Equaliser, a Digital Time Alignment Processor, as well as three pairs of 6.5 volts low-level output terminal. With all this functions onboard, external processors are not necessary.

This head-unit is equipped with Pioneer's renowned ASL (automatic sound leveliser) function which, when activated, automatically increases the music volume when road noise rises above a certain level.

Amplifier An Italian-made unit from Audio System, the F6-360, a 6-channel amp was chosen. The F6-360 has a continuous output power of 60 watts per channel. The amp is mounted on a custom-made rack located in the boot. Two channels are used to power the mid speakers and another are used to drive the tweeters. The remaining two channels are to drive the subwoofer system.

Front Speakers System Eton's component speakers, the A1-160, are used to reproduce the front-staging sound. Eton speakers have been exclusively made in Germany since 1983.

The mid drivers are mounted on custom-made baffleboards matched with black vinyl. These were then secured to the lower end of the front door panels. The front doors were treated with noise dampening mats from Brown Bread.

The Eton's tweeters are mounted on the ends of the dash­board, secured with 3M tapes. The passive-dividing networks that come in the component set were not used. The component speakers were divided using the active x-over network built into the Pioneer head-unit.

Cabling Speaker and power cables used are from Aura Dynamics, whereas the interlink cables between the head-unit and amp are from Macrom.

System Configuration A tatal of five speakers are used in this set-up. Rear-fill speakers had not been necessary.

This system war designed for a total front-staging reproduction with strong and proper imaging effect, just like listening to a home hi-fi set-up. This was achieved by activating the DTA (Digital Time Alignment) processors in the head-unit, which allows individual speaker's distance to the listener (one listener at a time) to be programmed into the head-unit. The DTA works by regulating the time-travel of the left and right speakers' sound, so that they arrive at the same time at the listener's ear, as if one were seated in the centre of a proper home hi-fi set-up. This is easier said than done as it requires a lot to achieve a properly executed set-up.

Tuning The system was tuned to reproduce a playback that sounds as close as possible to its original intended version. I am often asked what is meant by that statement? How do we know how it sounds? Well, let me simplify it by categorising it into three different parts of involvement: First, the musicians who make the music; second, the people who record the music into the medium, be it a cassette or CD; and, third, the playback of the medium on hardware, including amps, speakers, etc.

Ok, how do we know how the information recorded in the CD or cassette sounds like? A very simple way is by listening through a pair of headphones, one that has a well-balanced linear response but which does not have the low and high frequencies boosted to give an enhanced sound response. A good pair of headphones can offer fast and accurate references. Such headphones are used by professionals, people in the recording industry and related fields involving sound reproduction. I have used headphones from KOSS and my present unit is from AKG Acoustic, which is made in Austria.

Of course, building and tuning a proper car sound system involves more to that. It requires a wide range of knowledge, from simple 12-volts electronics to the parameters of car acoustic, and includes hostile car acoustic environment in relations to the parameters of the speakers. The speaker's compliance value will drastically change based on the physical manner they are installed.

Some of the common equipment used for system tuning includes the oscilloscope, meters and computerised analyser, and. of course, the ultimate tester - the human ear!

Conclusion A total of RM11.5k was spent on this project. Aff said that the amount is "enough to pay for five years' worth of baby milk powder". But he is very pleased and happy with his investment. If you ever bump into him, which should be easy enough if you attend the events of his BMW Club, don't be shy about asking for an audition of his car's system.