It is easy to be puzzled by the terminology which wireless loudspeaker suppliers employ in order to express the performance of their products. I will explain the meaning of a commonly utilized specification: "signal-to-noise ratio" in order to help you make an informed choice whilst getting a brand new a couple of cordless loudspeakers.
When you have narrowed down your search by glancing at some key criteria, such as the level of output power, the dimensions of the loudspeakers plus the price, you will still have quite a few products to choose from. Now it is time to look at some of the technical specs in more detail. An important criterion of wireless speakers is the signal-to-noise ratio. To put it simply, the signal-to-noise ratio shows how much hum or hiss the speakers will add to the music signal. This ratio is typically described in decibel or "db" for short.
One technique to do a simple check of the noise performance of a pair of cordless loudspeakers is to short circuit the transmitter audio input and then to crank up the wireless loudspeaker to its maximum. Subsequently listen to the speaker. Generally you are going to hear two components. The first is hissing. In addition, you are going to often hear a hum at 50 or 60 Hz. Both of these are components which are generated by the wireless loudspeaker itself. Then compare several sets of cordless loudspeakers according to the next rule: the smaller the amount of hiss, the better the noise performance of the cordless loudspeaker. Though, bear in mind that you should put all sets of cordless speakers to amplify by the same amount in order to compare several models.
Whilst looking at the cordless speaker spec sheet, you want to look for a set of cordless loudspeaker with a high signal-to-noise ratio number which suggests that the cordless speakers output a small level of noise. One of the reasons why cordless speakers produce noise is the fact that they use components including transistors as well as resistors which by nature produce noise. Mostly the elements which are situated at the input stage of the built-in power amplifier are going to contribute most to the overall noise. Thus manufacturers usually are going to select low-noise components when developing the cordless loudspeaker amplifier input stage.
An additional cause of static is the cordless audio broadcast itself. Generally products that make use of FM style broadcast at 900 MHz are going to have a comparatively high amount of hiss. FM transmitters are extremely prone to wireless interference which is why newer products typically employ digital audio broadcast. This style of music transmission provides better signal-to-noise ratio than analog style transmitters. The amount of noise depends on the resolution of the analog-to-digital converters along with the quality of other components.
Many latest wireless loudspeakers have built-in power amps that include a power switching stage which switches at a frequency around 500 kHz. This switching noise can result in a certain amount of loudspeaker distortion but is usually not included in the signal-to-noise ratio which only considers noise in the range of 20 Hz and 20 kHz.
Makers measure the signal-to-noise ratio by setting the built-in amp such that the full output swing may be achieved and by inputting a test signal to the transmitter that is generally 60 dB below the full scale of the loudspeaker amplifier. Subsequently, only the noise in the range of 20 Hz and 20 kHz is considered. The noise at different frequencies is eliminated via a filter. Subsequently the level of the noise energy in relation to the full-scale output wattage is calculated and shown in db.
One more convention in order to express the signal-to-noise ratio uses more subjective terms. These terms are "dBA" or "A weighted". You are going to discover these terms in many wireless speaker specification sheets. This method attempts to examine in how far the cordless loudspeaker noise is perceived by human hearing which is most perceptive to signals at frequencies at 1 kHz. An A-weighted signal-to-noise ratio weighs the noise floor according to the human hearing and is generally larger than the unweighted signal-to-noise ratio.
When you have narrowed down your search by glancing at some key criteria, such as the level of output power, the dimensions of the loudspeakers plus the price, you will still have quite a few products to choose from. Now it is time to look at some of the technical specs in more detail. An important criterion of wireless speakers is the signal-to-noise ratio. To put it simply, the signal-to-noise ratio shows how much hum or hiss the speakers will add to the music signal. This ratio is typically described in decibel or "db" for short.
One technique to do a simple check of the noise performance of a pair of cordless loudspeakers is to short circuit the transmitter audio input and then to crank up the wireless loudspeaker to its maximum. Subsequently listen to the speaker. Generally you are going to hear two components. The first is hissing. In addition, you are going to often hear a hum at 50 or 60 Hz. Both of these are components which are generated by the wireless loudspeaker itself. Then compare several sets of cordless loudspeakers according to the next rule: the smaller the amount of hiss, the better the noise performance of the cordless loudspeaker. Though, bear in mind that you should put all sets of cordless speakers to amplify by the same amount in order to compare several models.
Whilst looking at the cordless speaker spec sheet, you want to look for a set of cordless loudspeaker with a high signal-to-noise ratio number which suggests that the cordless speakers output a small level of noise. One of the reasons why cordless speakers produce noise is the fact that they use components including transistors as well as resistors which by nature produce noise. Mostly the elements which are situated at the input stage of the built-in power amplifier are going to contribute most to the overall noise. Thus manufacturers usually are going to select low-noise components when developing the cordless loudspeaker amplifier input stage.
An additional cause of static is the cordless audio broadcast itself. Generally products that make use of FM style broadcast at 900 MHz are going to have a comparatively high amount of hiss. FM transmitters are extremely prone to wireless interference which is why newer products typically employ digital audio broadcast. This style of music transmission provides better signal-to-noise ratio than analog style transmitters. The amount of noise depends on the resolution of the analog-to-digital converters along with the quality of other components.
Many latest wireless loudspeakers have built-in power amps that include a power switching stage which switches at a frequency around 500 kHz. This switching noise can result in a certain amount of loudspeaker distortion but is usually not included in the signal-to-noise ratio which only considers noise in the range of 20 Hz and 20 kHz.
Makers measure the signal-to-noise ratio by setting the built-in amp such that the full output swing may be achieved and by inputting a test signal to the transmitter that is generally 60 dB below the full scale of the loudspeaker amplifier. Subsequently, only the noise in the range of 20 Hz and 20 kHz is considered. The noise at different frequencies is eliminated via a filter. Subsequently the level of the noise energy in relation to the full-scale output wattage is calculated and shown in db.
One more convention in order to express the signal-to-noise ratio uses more subjective terms. These terms are "dBA" or "A weighted". You are going to discover these terms in many wireless speaker specification sheets. This method attempts to examine in how far the cordless loudspeaker noise is perceived by human hearing which is most perceptive to signals at frequencies at 1 kHz. An A-weighted signal-to-noise ratio weighs the noise floor according to the human hearing and is generally larger than the unweighted signal-to-noise ratio.
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