To help you select a set of wireless loudspeakers, I will clarify the term "signal-to-noise ratio" that is usually used in order to express the performance of wireless loudspeakers.
Once you have chosen a range of wireless speakers, it's time to investigate a few of the specs in more detail to help you narrow down your search to one product. Each wireless loudspeaker is going to produce a certain level of hiss as well as hum. The signal-to-noise ratio is going to help quantify the amount of noise created by the loudspeaker.
You can perform a simple assessment of the cordless speaker noise by short circuiting the transmitter input, setting the speaker gain to maximum and listening to the speaker. The static that you hear is generated by the cordless speaker itself. Next compare several sets of cordless speakers according to the next rule: the lower the level of hiss, the higher the noise performance of the wireless speaker. On the other hand, keep in mind that you have to put all sets of cordless speakers to amplify by the same level in order to evaluate several models.
In order to help you evaluate the noise performance, cordless loudspeaker producers publish the signal-to-noise ratio in their cordless loudspeaker spec sheets. Simply put, the larger the signal-to-noise ratio, the lower the amount of noise the cordless speaker creates. There are several reasons why wireless loudspeakers will add some form of hiss or other unwanted signal. Transistors and resistors which are part of each modern cordless loudspeaker by nature make noise. The overall noise depends on how much hiss each element creates. Nonetheless, the position of those elements is also vital. Components that are part of the speaker built-in amplifier input stage are going to normally contribute most of the noise.
The cordless transmission itself also causes static that is most noticable with types which use FM transmission at 900 MHz. FM transmitters are very prone to cordless interference which is why newer types commonly use digital music broadcast. The signal-to-noise ratio of digital transmitters is dependent by and large on the kind of analog-to-digital converters and other components which are utilized and also the resolution of the cordless protocol.
Most of recent wireless loudspeakers use power amplifiers which are digital, also called "class-d amps". Class-D amplifiers make use of a switching stage that oscillates at a frequency between 300 kHz to 1 MHz. This switching noise may result in some amount of loudspeaker distortion yet is usually not included in the signal-to-noise ratio which only considers noise between 20 Hz and 20 kHz.
The signal-to-noise ratio is measured by inputting a 1 kHz test signal 60 dB below the full scale and measuring the noise floor of the signal generated by the built-in amplifier. The amplification of the cordless loudspeaker is set such that the full output power of the built-in amp can be realized. Next, the noise floor between 20 Hz and 20 kHz is measured and the ratio to the full-scale signal computed. The noise signal at different frequencies is removed through a bandpass filter throughout this measurement.
Frequently the signal-to-noise ratio is shown in a more subjective way as "dbA" or "A weighted". In other words, this technique tries to state how the noise is perceived by a person. Human hearing is most sensitive to signals around 1 kHz whereas signals under 50 Hz and above 14 kHz are barely heard. An A-weighted signal-to-noise ratio weighs the noise floor in accordance to the human hearing and is usually larger than the unweighted signal-to-noise ratio.
Once you have chosen a range of wireless speakers, it's time to investigate a few of the specs in more detail to help you narrow down your search to one product. Each wireless loudspeaker is going to produce a certain level of hiss as well as hum. The signal-to-noise ratio is going to help quantify the amount of noise created by the loudspeaker.
You can perform a simple assessment of the cordless speaker noise by short circuiting the transmitter input, setting the speaker gain to maximum and listening to the speaker. The static that you hear is generated by the cordless speaker itself. Next compare several sets of cordless speakers according to the next rule: the lower the level of hiss, the higher the noise performance of the wireless speaker. On the other hand, keep in mind that you have to put all sets of cordless speakers to amplify by the same level in order to evaluate several models.
In order to help you evaluate the noise performance, cordless loudspeaker producers publish the signal-to-noise ratio in their cordless loudspeaker spec sheets. Simply put, the larger the signal-to-noise ratio, the lower the amount of noise the cordless speaker creates. There are several reasons why wireless loudspeakers will add some form of hiss or other unwanted signal. Transistors and resistors which are part of each modern cordless loudspeaker by nature make noise. The overall noise depends on how much hiss each element creates. Nonetheless, the position of those elements is also vital. Components that are part of the speaker built-in amplifier input stage are going to normally contribute most of the noise.
The cordless transmission itself also causes static that is most noticable with types which use FM transmission at 900 MHz. FM transmitters are very prone to cordless interference which is why newer types commonly use digital music broadcast. The signal-to-noise ratio of digital transmitters is dependent by and large on the kind of analog-to-digital converters and other components which are utilized and also the resolution of the cordless protocol.
Most of recent wireless loudspeakers use power amplifiers which are digital, also called "class-d amps". Class-D amplifiers make use of a switching stage that oscillates at a frequency between 300 kHz to 1 MHz. This switching noise may result in some amount of loudspeaker distortion yet is usually not included in the signal-to-noise ratio which only considers noise between 20 Hz and 20 kHz.
The signal-to-noise ratio is measured by inputting a 1 kHz test signal 60 dB below the full scale and measuring the noise floor of the signal generated by the built-in amplifier. The amplification of the cordless loudspeaker is set such that the full output power of the built-in amp can be realized. Next, the noise floor between 20 Hz and 20 kHz is measured and the ratio to the full-scale signal computed. The noise signal at different frequencies is removed through a bandpass filter throughout this measurement.
Frequently the signal-to-noise ratio is shown in a more subjective way as "dbA" or "A weighted". In other words, this technique tries to state how the noise is perceived by a person. Human hearing is most sensitive to signals around 1 kHz whereas signals under 50 Hz and above 14 kHz are barely heard. An A-weighted signal-to-noise ratio weighs the noise floor in accordance to the human hearing and is usually larger than the unweighted signal-to-noise ratio.
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