Advanced Car Audio Sound Quality Concepts

Although the four basic sound quality concepts (clarity, dynamic range, frequency response, and tonal balance) are the most fundamental to understand before purchasing a new car audio system, there are a few other sound quality attributes that are also important.

Timbre

Timbre (pronounced "TAM-bir") refers to a system's ability to recreate the sound of an instrument as it was originally intended to be heard. An acoustic guitar is usually a good test for this because most people have heard one. Does the sound have that warm, slightly resonant quality that the instrument is known for, or does it merely sound like a low-resolution reproduction of that signature sound?

Tonal accuracy

Tonal accuracy describes how faithful a system is in general to the original recording. It can apply to instruments as well as vocals. The more accurate the system is while playing a good recording, the more you feel as if you are there, listening to a live performance as opposed to a recording.

Tonal accuracy can also apply to the ambiance in a recording, which refers to the space in which a recording is made. Most modern recordings are made in a sort of vacuum, with individual instruments recorded separately or, in the case of some rap music, the individual parts are sampled from other recordings. But many older recordings, some modern ones, and almost all live albums capture the environment in which the performance was recorded. In fact, certain recording studios and performance spaces are known and revered for their sound, which give a recording or performance a specific ambiance.

Think of timbre and tonal accuracy as the reproduction of how close you get to the actual performance or how the producer intended for it to sound. Whether it's the sound of Miles Davis's trumpet, Jimmy Page's guitar, a Dr. Dre beat, or the ambiance of Carnegie Hall, how well a system can reproduce it the way it went down in a studio or concert hall determines the difference between a good system and a great one.

Staging and imaging

Staging and imaging are related concepts that go back to the heyday of stereo, and therefore don't always apply to modern music. The basic idea is that when you're listening to a stereo recording, the system should recreate the illusion of the stage on which the performance occurred, and you should be able to pinpoint the sonic image of the individual performers and instruments within the stage.

Think about the example of a basic rock band that includes a singer, guitarist, bass player, and drummer. You should be able to close your eyes and picture the singer at the center of the stage, the guitarist to the right, the bass player on the left, and the drummer center and behind the singer. Keep in mind that this is an ideal that sound quality systems should approach if not achieve. With rap and many pop-music recordings, the vocalist will be centered, but the concept of a band playing on a stage doesn't exactly apply.

Speaker placement has a dramatic effect on staging and imaging, and hardcore enthusiasts often go to great lengths to position their speakers for the best possible results. This includes rebuilding door panels to better position speakers. Some have even built elaborate mechanisms to mount speakers in or raise them above the dash in order to achieve better staging and imaging.

Finally, no discussion of sound quality would be complete without mentioning interior acoustics. A car's interior, its reflective surfaces (such as glass), and its absorptive materials (upholstery) play a dramatic role in a system's response. And every car interior is different; if you install the exact same components in your Toyota Camry that your friend has in his Chrysler 300C, the systems will sound very different.

Car Sound Deadening

Here's another fairly simple way to improve your car audio quality: sound-deadening materials. In most cars, the speakers are mounted in the front doors and behind the rear seats, usually facing up towards the rear window. The vibrations from these speakers can actually shake the car (or parts of the car), which can be noisy and will generally reduce the quality of the sound.

Sound deadening materials like Dynamat -- a cut-to-fit sheet of noise reducing material -- can absorb these vibrations when it's properly installed in your vehicle. Materials like Dynamat create a more stable platform to support the speaker, so the quality of the speaker won't be impaired by its own vibrations.

At the same time, Dynamat, or similar system, will reduce the noise from the road itself. If you have a small car or even a larger car that has thin doors or poor insulation, you know how loud road and wind noise can be at highway speeds. With a sound deadening material in place, you won't need to turn your volume quite as high to compensate for excessive road noise [source: Dynamat].

Up next, we'll look at how car audio accessories like amplifiers and head units can improve your audio quality.

Amplifiers, Receivers and Other Car Audio Equipment

Upgrading the car stereo receiver is a good way to get more audio options, like a better equalizer, clearer radio signals and even CD or MP3 player capability. But for dramatic improvements in sound quality, you'll need more than just a new car stereo.

Amplifiers are used to supply extra power to your car audio components. They do exactly what their name indicates -- they amplify­ electrical signals to send more juice to your entire audio system. The standard car stereo actually comes with its own, built-in amplifier; however, it's limited by space. Usually, these built-in amps are too small to send the power a high-fidelity custom stereo system requires.

As such, an external car audio amplifier is almost always necessary when you're running a lot of components in your system. If you're planning to purchase component speakers, tweeters and a subwoofer for your car, the stock power supply system just won't do this new car audio equipment justice.

With an amplifier, you can expect much higher quality sound from all of your car audio components. Amps can cost anywhere from $80 to several hundred dollars, depending on power output and the number of channels. The number of channels you need is dependent on the number of components you want the amp to power.

Proper tuning is also important to your stereo system. Even if you purchase all new sound equipment for your car, you'll still have to make sure the settings are right; otherwise the audio quality will remain poor. Set the car audio equalizer according to what you listen to most -- if you're into classical music or talk radio, maybe you don't need to the bass turned up to hip-hop levels. Most aftermarket stereos come with several pre-set options for tuning based on different types of listening. Select the one you like best, or tune it yourself.

One last piece of advice: Make sure the amplifier's gain control isn't set too high; otherwise you could face some nasty audio distortion issues. As for the radio, try to avoid excessive boosts in bass and treble, while turning the overall settings up a bit more [source: Fay].