Are you looking to get a brand new a pair of cordless loudspeakers for your home? You may be dazzled by the amount of choices you have. In order to make an informed selection, it is best to familiarize yourself with common specs. One of these specs is referred to as "signal-to-noise ratio" and is not frequently understood. I will help explain the meaning of this term.
Once you have selected a number of wireless loudspeakers, it's time to investigate a few of the specs in more detail in order to help you narrow down your search to one product. Each cordless speaker is going to make a certain level of hiss as well as hum. The signal-to-noise ratio is going to help calculate the level of noise produced by the loudspeaker.
A technique in order to accomplish a straightforward test of the noise performance of a set of cordless speakers is to short circuit the transmitter audio input and then to crank up the wireless speaker to its utmost. Subsequently listen to the speaker. The static that you hear is generated by the wireless speaker itself. Be certain that the gain of each couple of cordless speakers is set to the same amount. Otherwise you will not be able to objectively evaluate the amount of noise between several models. The general rule is: the smaller the amount of noise which you hear the better the noise performance.
While glancing at the wireless speaker spec sheet, you want to look for a couple of cordless speaker with a high signal-to-noise ratio number which suggests that the cordless speakers output a small level of static. One of the reasons why cordless loudspeakers generate noise is the fact that they utilize elements such as transistors and resistors which by nature generate noise. Mostly the elements that are located at the input stage of the built-in power amplifier will contribute most to the overall noise. Therefore suppliers typically are going to pick low-noise elements when developing the cordless speaker amp input stage.
Noise is also created by the cordless transmission. Different kinds of transmitters are available which operate at different frequencies. The least expensive sort of transmitters employs FM transmission and generally broadcasts at 900 MHz. FM transmitters are extremely prone to wireless interference which is why newer models typically make use of digital music broadcast. This kind of music transmission offers better signal-to-noise ratio than analog style transmitters. The amount of static depends on the resolution of the analog-to-digital converters and also the quality of other components.
A lot of of modern wireless loudspeaker use amps which are based on a digital switching topology. These amplifiers are referred to as "class-D" or "class-T" amplifiers. Switching amps include a power stage which is always switched at a frequency of approximately 400 kHz. This switching noise may cause some amount of speaker distortion yet is typically not included in the signal-to-noise ratio which only considers noise between 20 Hz and 20 kHz.
Manufacturers measure the signal-to-noise ratio by setting the built-in amplifier such that the full output swing may be achieved and by feeding a test tone to the transmitter which is generally 60 dB below the full scale of the speaker amp. Next, only the noise in the range of 20 Hz and 20 kHz is considered. The noise at other frequencies is removed by a filter. Next the level of the noise energy in relation to the full-scale output wattage is computed and shown in decibel.
Often the signal-to-noise ratio is shown in a more subjective way as "dbA" or "A weighted". This technique was developed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most sensitive to signals around 1 kHz. Though, signals below 50 Hz and higher than 13 kHz are hardly heard. The A-weighted signal-to-noise ratio is frequently higher than the unweighted ratio and is shown in the majority of cordless loudspeaker specification sheets.
Once you have selected a number of wireless loudspeakers, it's time to investigate a few of the specs in more detail in order to help you narrow down your search to one product. Each cordless speaker is going to make a certain level of hiss as well as hum. The signal-to-noise ratio is going to help calculate the level of noise produced by the loudspeaker.
A technique in order to accomplish a straightforward test of the noise performance of a set of cordless speakers is to short circuit the transmitter audio input and then to crank up the wireless speaker to its utmost. Subsequently listen to the speaker. The static that you hear is generated by the wireless speaker itself. Be certain that the gain of each couple of cordless speakers is set to the same amount. Otherwise you will not be able to objectively evaluate the amount of noise between several models. The general rule is: the smaller the amount of noise which you hear the better the noise performance.
While glancing at the wireless speaker spec sheet, you want to look for a couple of cordless speaker with a high signal-to-noise ratio number which suggests that the cordless speakers output a small level of static. One of the reasons why cordless loudspeakers generate noise is the fact that they utilize elements such as transistors and resistors which by nature generate noise. Mostly the elements that are located at the input stage of the built-in power amplifier will contribute most to the overall noise. Therefore suppliers typically are going to pick low-noise elements when developing the cordless speaker amp input stage.
Noise is also created by the cordless transmission. Different kinds of transmitters are available which operate at different frequencies. The least expensive sort of transmitters employs FM transmission and generally broadcasts at 900 MHz. FM transmitters are extremely prone to wireless interference which is why newer models typically make use of digital music broadcast. This kind of music transmission offers better signal-to-noise ratio than analog style transmitters. The amount of static depends on the resolution of the analog-to-digital converters and also the quality of other components.
A lot of of modern wireless loudspeaker use amps which are based on a digital switching topology. These amplifiers are referred to as "class-D" or "class-T" amplifiers. Switching amps include a power stage which is always switched at a frequency of approximately 400 kHz. This switching noise may cause some amount of speaker distortion yet is typically not included in the signal-to-noise ratio which only considers noise between 20 Hz and 20 kHz.
Manufacturers measure the signal-to-noise ratio by setting the built-in amplifier such that the full output swing may be achieved and by feeding a test tone to the transmitter which is generally 60 dB below the full scale of the speaker amp. Next, only the noise in the range of 20 Hz and 20 kHz is considered. The noise at other frequencies is removed by a filter. Next the level of the noise energy in relation to the full-scale output wattage is computed and shown in decibel.
Often the signal-to-noise ratio is shown in a more subjective way as "dbA" or "A weighted". This technique was developed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most sensitive to signals around 1 kHz. Though, signals below 50 Hz and higher than 13 kHz are hardly heard. The A-weighted signal-to-noise ratio is frequently higher than the unweighted ratio and is shown in the majority of cordless loudspeaker specification sheets.
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