What are frequency response, impedance, sensitivity for home theater speakers?

What are frequency response, impedance, sensitivity for home theater speakers?

There are many brands and models of speakers, and when purchasing home theater speakers, sometimes it is inevitable that there is no way to start. In addition to listening in person to understand the sound personality and orientation of the speakers, in fact, you can get a little understanding of the characteristics of the speakers from the basic specifications of the speakers.

Today I will introduce how to interpret the basic specifications of speakers such as "frequency response" and "sensitivity", so that beginners can "have a spectrum" of the data when purchasing.

The higher the level of speaker crossover, the more subdivided

Some speaker specifications will indicate the crossover design, such as two-way crossover, three-way crossover, etc. Sometimes the specifications are not written, but it can usually be distinguished from the shape of the speaker. Simply put, two units are two-way, and three units are three-way.

But sometimes it is not so simple. For example, many center speakers have three units, but they are only two-way division: the middle is the tweeter, and the two sides are mid-bass units; or some high-end floor-standing speakers have two sets of mid-range Sound or two sets of woofers, and even more "repeated" units to improve sound quality and increase output.

The appearance is relatively easy to identify, and usually the units responsible for the same frequency band will be the same. Theoretically, one unit can be responsible for the entire frequency range from 20Hz to 20kHz, and the sound will be the best without additional circuit "interference" such as crossovers. However, due to the limitations of unit design, the reality is that the finer the crossover, the higher the level of positioning.

Higher-end speakers usually have more detailed sound division, and the units are usually larger, and the difference can be clearly seen when compared with the same series.

Unit specifications (Drive Units) to understand the basic composition of speakers

Another important item that can be learned from the speaker specification list is the unit combination used. Bookshelf speakers usually adopt a two-way divider design, equipped with high and low-frequency units; most floor-standing speakers use three-way dividers, with three or more units for high, middle, and bass.

Satellite speakers or entry-level multimedia speakers are mostly just one unit. Some manufacturers will indicate the unit material, diaphragm material and other specifications will certainly affect the sound effect, but many times you can only know the characteristics of the unit and speaker from the manufacturer's description. As for the actual performance, you can only know by trying it.

The main thing worth paying attention to in the specification list is the size of the unit. Generally, the higher-end speakers will have more and larger units.

For example, two or more middle and bass units can make the output of middle frequency or low frequency more controllable. The wider the diameter of the unit, the better the bass dive, the stronger the amplitude, and the greater the output sound pressure.

However, these must of course cooperate with components such as diaphragms, drive circuits, and subwoofers. They can be expressed first, and they have reference value, but they are not absolute indicators. Taking the tweeter as an example, half-inch, 1-inch, and 1½-inch are all common sizes, 4-6 inches are common for mid-range units, and 5-10 inches are more common for woofers.

Frequency Response (Frequency Response) to reproduce the high and low bass ability indicators

Among the speaker specifications, one of the most important items is "frequency response". Simply put, it is the range of sound frequencies that can be reproduced to an "appropriate volume" when the speaker plays music or sound effects. Therefore, the frequency response is often marked as 20Hz - 20kHz (+/-3dB), 50Hz - 21kHz (+/-3dB), etc., which means that when receiving signals of the same voltage and different frequencies, 20Hz - 20kHz or 50Hz - 21kHz response (Response) volume changes within +/-3dB, is a common standard. However, ultra-low or ultra-high frequencies such as 15Hz and 22kHz may be -4dB, -5dB or even more. If the volume drops to too low and the "response" is too poor, it is not included in the frequency response range.

Among the audio that can be reproduced by the speaker, the output (sound pressure) of the head and tail (ultra-low frequency and ultra-high frequency) will be greatly attenuated, so it is not included in the "Frequency Response" (Frequency Response) range, but it is still Probably Frequency Range.

Most speakers can actually output audio outside of the frequency response. This larger audio range is called the "Frequency Range" (Frequency Range), which usually refers to the frequency at which the sound pressure is attenuated to within -6dB. Floor-standing speakers have larger units, so the bass can usually "dive deeper", and the low frequency may start at 20Hz or even lower frequencies; while bookshelf speakers are more common to start at 50Hz, 60Hz, etc.

the Impedance The "dynamic" resistance of a speaker

I believe everyone has heard of resistance. The concept of impedance is similar to that of resistance. It is the "resistance" of the speaker circuit's input surface resistance, capacitance, and inductance to alternating current (AC). The more common impedance values of speakers are 4Ω, 6Ω, 8Ω, etc. The lower the impedance, the greater the demand for current under the same power. In addition to being a burden on the power amplifier, it will also affect the sound quality. Nowadays, many power amplifiers can correspond to different impedances such as 4Ω and 8Ω.

At present, many power amplifiers can correspond to different resistance-amplified speakers. Taking Denon AVR-3700H as an example, it supports all ranges from 4Ω to 16Ω.

The speaker impedance and the highest acceptable input power are usually marked on the back of the speaker.

Sensitivity (Sensitivity) greater volume under the same power

Sensitivity is also another very important speaker specification. The higher the sensitivity of the speaker, the louder the volume will be under the same output of the power amplifier. For example, usually 50% volume of the power amplifier is just right, but if you change to a pair of speakers with higher sensitivity, 50% volume may be too loud. Sensitivity is measured in dB, under the input of 1W (or 2.83Vrms @ 8Ω), the sound pressure at a distance of 1 meter from the speaker, some output 1,000Hz audio and then measure it, and some output 300Hz to 3kHz average value to measure. Under this condition, most speakers will measure the sound pressure of 80dB to 90dB. Usually, the sensitivity above 88dB and 89dB is considered high, around 85dB is considered medium, and below 82dB is considered low.

There are many brands and models of speakers, and when purchasing home theater speakers, sometimes it is inevitable that there is no way to start. In addition to listening in person to understand the sound personality and orientation of the speakers, in fact, you can get a little understanding of the characteristics of the speakers from the basic specifications of the speakers.

Today I will introduce how to interpret the basic specifications of speakers such as "frequency response" and "sensitivity", so that beginners can "have a spectrum" of the data when purchasing.

The higher the level of speaker crossover, the more subdivided

Some speaker specifications will indicate the crossover design, such as two-way crossover, three-way crossover, etc. Sometimes the specifications are not written, but it can usually be distinguished from the shape of the speaker. Simply put, two units are two-way, and three units are three-way.

But sometimes it is not so simple. For example, many center speakers have three units, but they are only two-way division: the middle is the tweeter, and the two sides are mid-bass units; or some high-end floor-standing speakers have two sets of mid-range Sound or two sets of woofers, and even more "repeated" units to improve sound quality and increase output.

The appearance is relatively easy to identify, and usually the units responsible for the same frequency band will be the same. Theoretically, one unit can be responsible for the entire frequency range from 20Hz to 20kHz, and the sound will be the best without additional circuit "interference" such as crossovers. However, due to the limitations of unit design, the reality is that the finer the crossover, the higher the level of positioning.

Higher-end speakers usually have more detailed sound division, and the units are usually larger, and the difference can be clearly seen when compared with the same series.

Unit specifications (Drive Units) to understand the basic composition of speakers

Another important item that can be learned from the speaker specification list is the unit combination used. Bookshelf speakers usually adopt a two-way divider design, equipped with high and low-frequency units; most floor-standing speakers use three-way dividers, with three or more units for high, middle, and bass.

Satellite speakers or entry-level multimedia speakers are mostly just one unit. Some manufacturers will indicate the unit material, diaphragm material and other specifications will certainly affect the sound effect, but many times you can only know the characteristics of the unit and speaker from the manufacturer's description. As for the actual performance, you can only know by trying it.

The main thing worth paying attention to in the specification list is the size of the unit. Generally, the higher-end speakers will have more and larger units.

For example, two or more middle and bass units can make the output of middle frequency or low frequency more controllable. The wider the diameter of the unit, the better the bass dive, the stronger the amplitude, and the greater the output sound pressure.

However, these must of course cooperate with components such as diaphragms, drive circuits, and subwoofers. They can be expressed first, and they have reference value, but they are not absolute indicators. Taking the tweeter as an example, half-inch, 1-inch, and 1½-inch are all common sizes, 4-6 inches are common for mid-range units, and 5-10 inches are more common for woofers.

Frequency Response (Frequency Response) to reproduce the high and low bass ability indicators

Among the speaker specifications, one of the most important items is "frequency response". Simply put, it is the range of sound frequencies that can be reproduced to an "appropriate volume" when the speaker plays music or sound effects. Therefore, the frequency response is often marked as 20Hz - 20kHz (+/-3dB), 50Hz - 21kHz (+/-3dB), etc., which means that when receiving signals of the same voltage and different frequencies, 20Hz - 20kHz or 50Hz - 21kHz response (Response) volume changes within +/-3dB, is a common standard. However, ultra-low or ultra-high frequencies such as 15Hz and 22kHz may be -4dB, -5dB or even more. If the volume drops to too low and the "response" is too poor, it is not included in the frequency response range.

Among the audio that can be reproduced by the speaker, the output (sound pressure) of the head and tail (ultra-low frequency and ultra-high frequency) will be greatly attenuated, so it is not included in the "Frequency Response" (Frequency Response) range, but it is still Probably Frequency Range.

Most speakers can actually output audio outside of the frequency response. This larger audio range is called the "Frequency Range" (Frequency Range), which usually refers to the frequency at which the sound pressure is attenuated to within -6dB. Floor-standing speakers have larger units, so the bass can usually "dive deeper", and the low frequency may start at 20Hz or even lower frequencies; while bookshelf speakers are more common to start at 50Hz, 60Hz, etc.

Impedance The "dynamic" resistance of a speaker

I believe everyone has heard of resistance. The concept of impedance is similar to that of resistance. It is the "resistance" of the speaker circuit's input surface resistance, capacitance, and inductance to alternating current (AC). The more common impedance values of speakers are 4Ω, 6Ω, 8Ω, etc. The lower the impedance, the greater the demand for current under the same power. In addition to being a burden on the power amplifier, it will also affect the sound quality. Nowadays, many power amplifiers can correspond to different impedances such as 4Ω and 8Ω.

At present, many power amplifiers can correspond to different resistance-amplified speakers. Taking Denon AVR-3700H as an example, it supports all ranges from 4Ω to 16Ω.

The speaker impedance and the highest acceptable input power are usually marked on the back of the speaker.

Sensitivity (Sensitivity) greater volume under the same power

Sensitivity is also another very important speaker specification. The higher the sensitivity of the speaker, the louder the volume will be under the same output of the power amplifier. For example, usually 50% volume of the power amplifier is just right, but if you change to a pair of speakers with higher sensitivity, 50% volume may be too loud. Sensitivity is measured in dB, under the input of 1W (or 2.83Vrms @ 8Ω), the sound pressure at a distance of 1 meter from the speaker, some output 1,000Hz audio and then measure it, and some output 300Hz to 3kHz average value to measure. Under this condition, most speakers will measure the sound pressure of 80dB to 90dB. Usually, the sensitivity above 88dB and 89dB is considered high, around 85dB is considered medium, and below 82dB is considered low.