There are two evaluation standards for sound quality, one is objective standards, that is, instrument testing standards; the second is subjective evaluation standards. Among them, the instrument testing standards (ie, objective standards) are clear, and subjective standards vary from person to person. Therefore, first of all, it is necessary to detect good performance objectively, which is a good speaker and foundation. Of course, subjective evaluation should be based on "good analytical power (" "High music clarity)", "strong sense of vividness (speaker performance music is more lively)", "good image formation (sound cohesion, good positioning)", "airy (good elasticity)", "high transparency (high pitch) Good penetration)", "energy density", "deep dive (rich bass)", "resonance", "self-excited", "harmonics", "piercing", "irritable", "fog", "fuzzy", "floating"" Narrowness, "weakness," "tailing," and so on are all subjective evaluation terms that describe bad speakers.
Five criteria for evaluating speakers
(1) The midrange part of voice and singing should be open
If the voices of singers of different styles sound a little bit nasal, a little dull or dry, you can be sure that there is something wrong with the speaker's response to the mid-range.
(2) The mid-bass should be free of distortion
The investigation of midrange is mainly based on human voice, which is approximately within the frequency range of 150Hz-2500Hz, including speech and singing. It is mainly to distinguish the coloring phenomenon of mid-frequency that speakers are most likely to have, such as humans. Unsteady voice, incoherent pitch, obvious low-heavy "nasal" phenomenon in the human voice, dry, hollow, and muffled voice, ——These can all be regarded as obvious defects of the speaker. Even the smallest bookshelf speaker still has some output in the low frequency range. If the bass guitar sound is not very clear, some are too loud or rumble, or even a certain scale or group of scales is too loud, it means that the speaker is right. The response of the frequency from 60 to 150 Hz is not very good. If the thick male voice sounds a bit "cavity" or a little contrived, it also shows that the response in this frequency band is not good.
(3) Don't have problems with the high range
Although some music does not have a lot of high pitches (referring to the 10-20kHz section), there are obvious high pitches in jazz and rock music. Therefore, you can test and listen to jazz CDs with good recording quality. In this type of CD record, there are always some clear momentary transitions that will appear over and over again. When auditioning, listen carefully for dullness or ambiguity that "enthusiasts" often say. In the low and treble part, plucked music, orchestral and symphony sources are mainly used for listening and evaluation. The sound is required to be natural and soft, light in rhythm, and clear in outline. It should be noted whether the sound has obvious feeling of dryness and excessive stickiness. In short, This range has higher requirements for the listener and sound source, and the speaker can meet the above requirements, we think it is better, and no more demanding requirements. In the ultra-high range, we use clear jazz and some special sound sources such as cracking, splitting, and humming, mainly to investigate the transient expressiveness of the loudspeaker's treble. In the repeated transient treble, see whether the speaker sounds crisp, clean, harsh, and whether there are obvious distortion phenomena such as burrs, splitting sounds, and rustling sounds.
Because the human ear has a relatively poor sense of bass, so the distortion can not be too much care, we mainly see whether the bass is thin and weak, whether it is hollow and dry ——like it is emitted from a paper box or a small wooden box, in order to be calm , Dignified and vigorous is better. At this point, the woofer has good material, large volume, box weight, thick plate, and well-sealed speakers will have better expressive power.
(5) How to use audio equipment safely? This article provides some helpful suggestions for your reference: 1. Pay attention to the conditions of use of the machine
Generally, the operating conditions of the machine are listed in the operating instructions of the machine, such as: 1. Ambient temperature: -10°C--+40°C 2. Relative humidity: 50%--80% 3. Power supply voltage: 198V—242V4. Power frequency: 50Hz—60Hz specifically, it is the requirements: 1. Avoid using the machine in an extremely low or extremely high temperature environment, and avoid direct sunlight on the surface of the machine. 2. Avoid using the machine in a humid environment to avoid premature failure of internal components or premature rusting of the machine. 3. Before using, it must be confirmed that the local power supply voltage is consistent with the machine.
2. Pay attention to the use environment of the machine
1. Avoid using the machine in dust and vibration environments.
2. There should be enough space around the machine to facilitate the heat dissipation of the machine.
3. For power amplifiers, special attention should be paid to keeping the heat dissipation channels unblocked.
3. Points to note in the use of the machine
In the audio system, attention should be paid to the sequence of turning on and off. When turning on the device, turn on the pre-equipment such as the audio source first, and then turn on the power amplifier; when turning off the device, turn off the power amplifier first, and then turn off the pre-equipment such as the audio source. If the audio equipment has a volume knob, it is better to turn the volume knob to the minimum before turning it on or off. The purpose of this is to reduce the impact on the speaker when it is turned on and off.
It is strictly forbidden to unplug or plug in signal plugs when powered on. So as not to damage the machine or speakers due to the resulting impact.
If the machine makes abnormal noises during operation, immediately turn off the power supply and stop using it. And ask experienced and qualified maintenance personnel to repair it. Do not open the machine without authorization, so as to avoid greater damage to the machine or electric shock.
Four. Pay attention to the maintenance of the machine
Do not use volatile solutions to clean the machine. For example, use gasoline, alcohol, etc. to wipe the surface of the machine. For dust, use a soft cloth. And unplug the power first when cleaning the machine shell.
The machine is generally not waterproof. In case it gets wet, use a dry cloth to wipe off the water stains. After the water is dry, the machine can be turned on.
Do not place heavy objects on the machine to avoid deformation of the machine.
V. Safe use of the machine
Do not pull or plug in the power plug with wet hands to avoid electric shock.
When not in use for a long time, please unplug the power plug from the power socket.
Do not let metal conductive materials such as iron needles, hairpins, coins, etc. fall into the machine to avoid damage to the machine.
When replacing the fuse of the machine, it should be replaced strictly according to the requirements, and it is strictly prohibited to use substandard substitutes.
When the machine is in use, the grounding point of the chassis should be safely grounded.
The machine is strictly prohibited to work under overload or short circuit conditions.
Generally, there are auxiliary power sockets on the back panel of civil power amplifiers. Do not connect electric appliances such as hair dryers and irons through it. It can only be used to connect audio equipment.
In a constant voltage power amplifier, the output terminal will have a higher output voltage, and the output terminal lead is generally longer, so in use, we must ensure the safety and reliability of the output terminal lead.
6. Pay attention to the protection of the power cord
Take care to avoid the power cord being stepped on or crushed by heavy objects.
Do not pull, plug, or forcefully twist the power cord.
When pulling out the plug from the socket, grasp the plug and pull it out.
In short, modern audio equipment is a high-tech product, which must be carefully maintained, used safely, and operated correctly. In order to gain the enjoyment of beauty, and avoid accidental losses.