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Published on July 25, 2007

In its original state, music is recorded on to audio masters by sound engineers in a studio. It is as close to perfection as they can make it. But then the CD tracks that carry this perfection must be transformed into sound signals by the components of an audio system that are just as likely to distort the sound as to faithfully reproduce it. It bears repeating, therefore, that high-end (and high-cost) components are far superior to their low-end counterparts because they cause less distortion.

Of all the audio components, loudspeakers are probably the most critical, because they are the final destination for all of the effort of recording and reproducing the sound. Speaker systems cannot be good if the installation is not up to standard. The acoustic environment, comprising all of the hard and soft surfaces inside your car, is also critical to getting a great sound. In fact the internal acoustic environment is usually highly reverberant and can create directionless dispersion of sound because of the variety of materials inside a car. Windshields and windows tend to reinforce strong reverberation and high frequencies while cloth seats tend to absorb them. Too many sound-absorptive materials, such as mats and adhesive strips, will degrade overall sound quality.

There is also the "bass-boom" situation, where low frequencies are lifted and muffle the high frequencies. In many cases, accessories like interconnect cables, speaker wires and equalisers can upgrade high frequencies, but adding accessories doesn't always help, because the cause of the problem, the acoustic environment, has not been fixed.

The position of the speakers always has a direct relationship to volume levels and the acoustic environment. Therefore speaker position is critical for the stereo image and sound-stage effect. Reverberation will be more intense if woofers and tweeters are installed to fire directly towards the rear windshield, and this will also create a sound delay between the front and rear speakers. Thus tuning and balancing the sound between the front and rear speakers becomes important. Among the solutions to reduce reverberation is to cross-fire the left and right systems and in some cases even to reverse the rear speaker channels. The key is to direct the speakers towards the passengers. Good installers should be well aware of these principles.

After the speaker system is finally installed, you need to further tune the system on fader and balance controls to ensure perfect matches of overall image and sound-stage effect. The process is known as fader control. You increase the volume in the front speaker channels while reducing it in the rear speaker channels. Gradually adjust the faders not only to achieve volume balance between the front- and rear-mounted speakers but also to optimise the sound-stage effect.

Unfortunately, many cheap head units have low-quality faders. If you really want great stereo sound-tuning, your primary focus should be control of fader, especially when it comes to selecting a head unit for your audio system.

By Wijit Boonchoo

Ultimate in Luxury

The Luxury LS 460 is a wonderfully comfaortable car fitted with all mod cons, althoough not necessarily the most fun vehicle to drive.