Dead man’s curve

Driving on the streets of Manila is oftentimes a death-defying exercise. Almost daily, motorists have to contend with pothole-riddled roads made worse by busted water pipes, snail-paced or unfinished road repairs, road rage and corrupt traffic enforcers, among other deadly distractions.

My Argentinean friend Ruben Valenti marvels at how Filipinos can remain relatively unscathed by such dismal driving conditions, with only their blood pressure raised by a few notches.

The secret may be that most Filipino motorists are crazy about music. More often than not, their cars are equipped with sound kits that can rein in their road rage or frustration.

Mobile audio or car audio is one of the smartest ways to safely navigate Manila’s dead man’s curve. Most motorists spend substantial time and money installing these gadgets in their cars, not only to insulate them from road nuances, but mainly to give them the opportunity to enjoy the music of their favorite artists. Mobile audio has even evolved into a solemn hobby, which has spawned groupings among car audio enthusiasts who organize annual competitions to adjudge the best-sounding mobile audio system.

In December last year, Audiofile was invited to be one of the judges in the competition organized by the Kotse-Audio Club (KAC). Unfortunately, I had to beg off because the contest date coincided with the Hi-Fi Show, of which I was very much a part of. This corner, however, donated a cash prize of P20,000 for the KAC contest organizer to give out to whoever proved deserving.

Let’s face it: cars offer the most hostile acoustics. This is why I tip my proverbial hat off to car audio installers who are gifted with the talent of making sound waves in cars pleasant to the ears. 

The problem with cars is that manufacturers put the sound system last in the assembly line. Only after all the bolts, metals and rubbers have been assembled is the placement of the car speakers given consideration.

If you were at home, the size of your music room limits the capability of your system to reproduce quality sound. In mobile audio, your room is your car, which is by no stretch of the imagination an ideal listening haven. Inside your car, good music competes with road, engine and wind noise. Any clatter inside and outside your vehicle will alter your sound system’s sonic performance.

When you listen to music with your home audio system, you won’t be foolish enough to position yourself near any of your speakers, which would make you miss the details that your left or right speaker gives out and also the breadth of a full-stereo image. You get the same uneven results if you listen to music from your car’s built-in speaker system while sitting on the driver’s seat.

In this situation, you hear the sound on your left way ahead of the sound on your right. This radically alters your system response. Within certain bandwidths, some frequencies are emphasized over others, totally distorting the soundstage. Installers make sure that the placement of your car’s speakers results in proper sound imaging, which requires a close-to-equal path length between your ears and your speakers.

Imaging is the capacity of your audio system to recreate sounds that, even with your eyes shut, will let you imagine where the sound instruments are — from right to left in any kind of recording. Imaging is important to people who have a high taste for music, whether they are simple enthusiasts or serious competitors. If your system has better imaging, you can easily tell where the voices and instruments are, and they should not seem to change with frequency fluctuations.

The speakers, likewise, would seem invisible. In their stead is this spatial harmony of various sources of music often called “soundstage.” Although soundstage is recreated by your front and rear speakers, the music should seem to emanate from in front of you, engulfing the space from left to center to right.

To overcome this limitation, some installers mount front car speakers on a set of customized kick panels. They install them under dashboards in the far left and right corners of car interiors. With separates located in the pods by your feet, equal path lengths are thus achieved.

Fortunately, many inexpensive products that offer imaging solutions abound on the market today. Now, rotating pods and lenses are built into full-range speakers. These products allow tweeters to be turned directly at the listener. Focusing high frequencies to the listening position does improve soundstage, but since the full-range speakers are still factory installed, the soundstage is not what it should be. To compensate, installers mount additional tweeters and midranges on the dashboard on each side of the listener.

It’s challenging indeed to cheat the dead man’s curve, but it can be highly fun and certainly worthwhile if you have the passion, patience and resources.

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For comments or questions, please e-mail me at audioglow@yahoo.com or at vphl@hotmail.com. You can also visit www.wiredstate.com for quick answers to your audio concerns.