In practical application, the frequency range and frequency response of audio have always been a matter of great concern, but because of the professional subdivision knowledge, many people's understanding of frequency range and frequency response is relatively one-sided. What is the difference between frequency range and frequency response? Is it that the higher the frequency, the better the acoustics? What is the appropriate frequency of the audio? For such problems, Xiaobian has compiled the following compilation: 1.

Definition
of frequency range and frequency response The frequency range refers to the range between the lowest effective playback frequency and the highest effective playback frequency that the audio system can replay; Frequency response refers to a constant voltage output audio signal with the system when the sound pressure generated by the speaker increases or attenuates with the change of frequency, phase changes with the frequency of the phenomenon, this sound pressure and phase and frequency associated change relationship (change amount) is called frequency response, unit decibels (Db).

Second, the frequency of the audio system to discriminate the frequency characteristics of the audio system are often described by the ordinate of the decibel scale to
express the power and the frequency response curve of the abscissa of the logarithmic scale to express the frequency. When the sound power is 3dB lower than the normal power, this power point is called the high-frequency cut-off point and low-frequency cutoff point of the frequency response. The frequency between the high-frequency cutoff point and the low-frequency cutoff point is the frequency response of the device; The curves of sound pressure and phase lag as a function of frequency are called "amplitude-frequency characteristics" and "phase-frequency characteristics", respectively, and are collectively referred to as "frequency characteristics". This is an important indicator to examine the performance of the speaker, it is directly related to the performance and price of the speaker, the smaller the decibel value, the flatter the frequency response curve of the speaker, the smaller the distortion, the higher the performance. For example, the frequency response of a speaker is 60Hz~18kHz+/-3dB. These two concepts are sometimes not distinguished, which is called frequency response

Third, how high is the frequency of the sound more appropriate?
Theoretically, the frequency response of 20~20000Hz is sufficient. Sound below 20Hz can not be heard but can be perceived by other human sensory organs, that is, the so-called bass power can be felt, so in order to perfectly play various musical instruments and language signals, the amplifier must achieve the goal of high fidelity, so that all harmonics of the tone can be reproduced. Therefore, the frequency band of the amplifier should be expanded, the lower limit should be extended below 20Hz, and the upper limit should be increased to more than 20000Hz. The frequency response is represented differently for sources (radios, recorders, record players, etc.). For example, the frequency response of FM stereo broadcasting stipulated by the European Broadcasting Union is ten / - 2dB when 40~15000Hz, and the minimum frequency response index specified by the International Electrotechnical Commission for the recording seat: 10/—2.5 ten/—4.5dB (ordinary band) at 40~12500Hz, and the actual indicators that can be achieved are significantly higher than this value. The upper limit of the frequency response of the CD player is 20,000Hz, and the low frequency end can be very low, only a few hertz, which is one of the reasons for the good playback quality of the CD player.

4. The wider the frequency range, the better the acoustics?
The harmonic components that make up the sound are very complex, not the wider the frequency range, the sound is good, but this is basically true for low-end multimedia speakers. In the labeling frequency response we usually see the terms "system frequency response" and "amplifier frequency response", to know that "system frequency response" is always smaller than the range of "amplifier frequency response", so only marking "amplifier frequency response" does not make any sense, this is only used to deceive some uninformed consumers. Now speaker manufacturers generally mark the range of system frequency response is too large, the high frequency part is not very bad, but in the low end of the label is extremely untrue, foreign famous brand HiFi (high fidelity) speakers are only marked 4, 50Hz or so, and domestic two or three hundred wooden ordinary speakers actually dare to mark this data, really make people laugh off the big teeth! Therefore, I would like to warn everyone that low-frequency sounds must be heard as true, and do not easily believe the values on the leaflet. The music in the multimedia speaker is mainly to play MP3 or CD music, songs, game sound effects, background music and human and ambient sound effects in the film, these sounds are mostly mid-high sound, so when choosing multimedia speakers, you should pay more attention to its ability to express sound in the middle and high frequency bands, rather than low frequency bands. If you are really looking for cinematic results, then a powerful subwoofer will definitely meet your needs.