Evaluation of Car Audio Sound Quality - Car Beauty Hub - wzkary005 - Hexun Blog

Evaluation of Car Audio Sound Quality

What constitutes a good car audio system? According to IASCA standards, it includes good sound quality, safe circuitry, complete installation, attractive craftsmanship, unique creativity, precise frequency response, and impressive sound pressure. Unfortunately, Chinese car owners are among the busiest in the world. They desire a CAR AUDIO SYSTEM that reflects their personal taste both in appearance and essence, but they don't have enough time to leave for audio modification shops to meet their requirements. Meanwhile, modification shops need to demonstrate their professional level, hence the streets are filled with modification results done merely for the sake of craftsmanship. If general car owners are not familiar with the craft requirements of appearance, then a safe audio system with excellent sound quality should be your favorite.

In car audio, what is considered good sound quality? Most audio modification professionals and audiophiles use home audio as a reference. The soundstage positioning and music reproduction of home audio are indeed the goals pursued by car audio. However, the lifelike live sound effects produced in car audio are beyond the reach of ordinary home audio. Therefore, another reference has been added to car audio - headphones. If you've used excellent headphones to enjoy music, you probably remember the feeling of floating in space. In this narrow, enclosed, and highly absorptive environment of a car, the ultra-wide frequency and balanced response of headphones is the "Utopia" that car audio seeks.

How to evaluate the sound quality of a car audio system? Hereby, I would like to quote the evaluation rules from the International Car Audio Competition to share with everyone.

A. Linearity of sound

B. Accuracy of pitch and balance across all frequency bands

C. Imaging localization

D. Soundstage and reverberation

Among these, accuracy of pitch and balance across all frequency bands are the main parts. The accuracy of pitch is affected by six characteristics:

A. Loudness (LOUNDESS) It refers to the intensity of auditory stimulation caused by sound. It can be affected by poor EQ or speaker sound pressure matching.

B. Pitch (PITCH) It determines the position of sound on the musical scale. It is a subjective quality. Excessive distortion and non-linearity can affect pitch.

C. Timbre (TONE) It is the sound characteristic produced by the interaction of the fundamental tone and overtones of a certain sound. It is related to the nature of equipment and cables.

D. Duration (DURATION) It is the length of time the sound lasts. It can be affected by the system's state response or baffle resonance.

E. Attack and decay (ATTACK AND DECAY) The time required for sound to increase from small to large (attack) and decrease from large to small (decay). It can be adversely affected by poor system response, baffle resonance, and strong early reflections.

F. Modulation (MODULATION) It refers to the changes in sound in terms of size, phase, or frequency. It can be affected by the system's phase and frequency response.

Based on the above six points, we can divide the sound into four frequency bands for identification. Sub-bass (18-60Hz) This band represents all large string instruments, bass drums, low-frequency synthesizers, pipe organs, etc. Under the system's reproduction, the sound in this band should be clearly distinguishable, with genuine quantity and elasticity, good extension, and no distortion. A common defect in this band is that the sub-bass becomes muddy due to excessive decay time or blurred sound. The lowest frequency band of the pipe organ is a good example. Mid-bass (60-200Hz) It represents medium-sized drums (Indian drums, large Latin drums), the midrange of bass guitars and double basses, the low notes of pianos and sound effect synthesizers. It requires smooth regeneration of elastic and detailed sounds. The difficulty lies in representing the impact sound and staccato of drums and bass guitars. This is a very challenging frequency band for all audio modification shops because there may be resonance or wave peaks in the vehicle body at this frequency band, affecting the accurate reproduction of sound.

The drum sound in the first section of "Hotel California" is the preferred test music. A good system should represent the tension, size, and impact of hand-drummed drums. A common defect we often see is exaggerating the drum sound as low-frequency synthesizer sound. Midrange (200-3000Hz) This is an important frequency band. It contains most of the musical information and is also the most sensitive frequency band for human ears. The difference between excellent speakers and ordinary ones lies in this frequency band. Basically using vocals as a reference, vocals should sound real and full without any unnatural feelings such as dimness or distortion. High frequency (3000-20000Hz) In the strongly reflective environment inside a car, it is conducive to the normal performance of high frequencies. However, due to the influence of installation position and improper attenuation, most car audio systems' high frequencies are overly bright, exposing rough texture and excessive sibilance. After independent evaluations of the four frequency bands, we need to consider the balance of the entire musical frequency range. It represents the pitch accuracy of the system across the entire audio bandwidth. A common balance defect domestically is the excessive amplification of sub-bass, which is why many car owners dislike installing subwoofers!

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