How do you identify the sound quality of speakers？— Conditions required to evaluate speaker sound quality.

Not all speakers can produce good sound, so how to evaluate the sound quality? This is difficult for many music lovers to grasp. Sometimes there is a situation where different people will give different sound quality evaluations for the same speaker. So, is there a set of subjective evaluation standards in the industry? So far, not yet. However, we can carry out the subjective evaluation of sound quality through as rigorous and scientific methods as possible. Below we will introduce some knowledge related to the subjective evaluation of sound quality.

For audio equipment or theater systems, their sound cannot be fully measured using parametric indicators. The subjective evaluation of audio equipment is the evaluation of the characteristics of the equipment by listening methods under the conditions that the environment and programs can be controlled. Also, subjective evaluation of just a single piece of equipment is often difficult, so comparisons are usually made with standard equipment or among multiple pieces of equipment to obtain comprehensive effect feeling and evaluation results of estimation of loudness, frequency range, tonal balance, spatial distribution, quality, and non-uniformity.

 

First, the subjective evaluation of sound quality should meet the conditions.

 

The evaluation of sound quality depends on many factors, such as sound source characteristics (sound pressure, frequency, spectrum, etc.), signal characteristics of audio equipment (such as distortion, frequency response, dynamic range, signal-to-noise ratio, transient characteristics, stereo Separation, etc.), sound field characteristics (such as direct sound, early reflection sound, reverberation sound, cross-correlation coefficient between the two ears, reference vibration, sound absorption rate, etc.), auditory characteristics (such as loudness curve, audible range, various hearing senses ) and so on. Therefore, this requires the evaluator to listen to various sound effects in a relatively standard environment.

 

• Using the current high performance audio system equipment

When listening to a certain audio equipment, it must be composed of the product and some other audio equipment to form a sound playback or pickup system. Due to the rapid development of the audio industry, in addition to the obvious differences in objective indicators, different equipment and equipment also have their own inherent "timbre", so there is currently no so-called "standard sound". This requires that the best current equipment should be selected as far as possible in the subjective listening evaluation, so as to reduce the introduction of additional influencing factors to the subjective evaluation. At present, there are many top-level "reference-level" products launched by many manufacturers in the world. Although it cannot be said that these products have reached the ideal level, their excellent performance is sufficient to be used as standard equipment.

 

• Selection of signal sources and program speaker materials

The use of different program speaker sources when evaluating sound quality will have a great impact on the evaluation results. Therefore, the program sources for sound quality evaluation should not only be systematic and comprehensive, including music and voice of different genres and styles, but also have strict recording and production requirements to ensure that there are sufficient frequency bands and amplitudes.

 

• Meet the acoustic requirements of the listening room

The influence of the listening environment on the sound quality is undeniable. Due to the different structure, shape, volume, and internal surface sound absorption treatment methods of different listening rooms, the acoustic parameters of the rooms are different. In this way, different conclusions will be drawn when the same audio product is evaluated in different rooms. Therefore, certain acoustic conditions should be regulated for the listening room used in the listening evaluation to reduce the influence of the listening room on the evaluation results. In addition, the listening room should have a suitable temperature, humidity, and light to prevent these factors from affecting the mood of the auditors.

 

• Requirements for sound quality assessors

Because the sound quality evaluation has a strong personal subjective color, the individual differences in the listener's occupation, physiology, emotion, and cultural accomplishment directly affect the evaluation results of the sound quality. Therefore, when subjectively evaluating the sound quality of audio products, the selection of members of the audition group is very important. The members of the audition group not only have high requirements for the sensitivity of hearing itself (referring to the conditions of the human ear itself), but also must have the ability to evaluate the aesthetics of sound quality, and the ability to evaluate the quality of musical instruments and other sound sources.

At the same time, the sound quality evaluation can be related to the objective technical indicators of the audio product. When there is a slight sound quality difference in the product, what kind of sound source is heard to distinguish the sound, and what attributes are used to judge the sound quality difference.

In order to minimize the sound quality evaluation errors caused by individual differences of the listeners, members of an auditioned group may include scientific and technical workers engaged in stereo and architectural acoustics, electroacoustics, and acoustics, recording and tuning technicians, as well as musicians, music editor and film and music director, actor.