To help you choose a couple of cordless speakers, I am going to clarify the term "signal-to-noise ratio" that is regularly utilized in order to explain the performance of cordless speakers.
As soon as you have selected a range of wireless loudspeakers, it's time to explore several of the specifications in more detail in order to help you narrow down your search to one product. Each cordless loudspeaker is going to generate a certain amount of hiss and hum. The signal-to-noise ratio is going to help calculate the level of static generated by the speaker.
You can make a straightforward assessment of the cordless speaker noise by short circuiting the transmitter input, setting the loudspeaker gain to maximum and listening to the speaker. Typically you are going to hear 2 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 created by the wireless loudspeaker itself. After that compare several sets of wireless speakers according to the following rule: the lower the level of static, the higher the noise performance of the cordless speaker. Though, keep in mind that you have to put all sets of cordless loudspeakers to amplify by the same amount to evaluate different models.
If you favor a set of wireless loudspeakers with a small level of hissing, you may look at the signal-to-noise ratio number of the data sheet. A lot of makers will display this number. wireless loudspeakers with a large signal-to-noise ratio will output a small amount of noise. One of the reasons why cordless speakers produce noise is the fact that they utilize components like transistors and resistors which by nature produce noise. The overall noise is dependent on how much noise every element creates. However, the position of these components is also important. Components which are part of the loudspeaker built-in amp input stage are going to generally contribute the majority of the noise.
The wireless broadcast itself also creates hiss which is most noticable with types which utilize FM transmission at 900 MHz. Other cordless transmitters are going to interfer with FM type transmitters and create further static. For that reason the signal-to-noise ratio of FM type wireless loudspeakers varies depending on the distance of the speakers from the transmitter plus the level of interference. To avoid these problems, modern transmitters employ digital music transmission and generally transmit at 2.4 GHz or 5.8 GHz. The signal-to-noise ratio of digital transmitters depends mostly on the kind of analog-to-digital converters and other components which are utilized along with the resolution of the cordless protocol.
A lot of of recent wireless loudspeaker use amps which are based on a digital switching architecture. These amplifiers are named "class-D" or "class-T" amps. Switching amplifiers incorporate a power stage which is constantly switched at a frequency of approximately 400 kHz. In consequence, the output signal of wireless speaker switching amplifiers exhibit a rather big amount of switching noise. This noise component, however, is typically impossible to hear because it is well above 20 kHz. Though, it may still contribute to speaker distortion. Signal-to-noise ratio is typically only shown within the range of 20 Hz to 20 kHz. Therefore, a lowpass filter is utilized while measuring cordless loudspeaker amplifiers to eliminate the switching noise.
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 amp. The gain of the cordless speaker is set such that the full output wattage of the built-in amp can be realized. Next the noise-floor energy is calculated in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy.
One more convention to state the signal-to-noise ratio utilizes more subjective terms. These terms are "dBA" or "A weighted". You are going to discover these terms in most wireless loudspeaker parameter sheets. This method was developed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most responsive to signals around 1 kHz. Though, signals under 50 Hz and above 13 kHz are barely noticed. An A-weighted signal-to-noise ratio weighs the noise floor according to the human hearing and is generally higher than the unweighted signal-to-noise ratio.
As soon as you have selected a range of wireless loudspeakers, it's time to explore several of the specifications in more detail in order to help you narrow down your search to one product. Each cordless loudspeaker is going to generate a certain amount of hiss and hum. The signal-to-noise ratio is going to help calculate the level of static generated by the speaker.
You can make a straightforward assessment of the cordless speaker noise by short circuiting the transmitter input, setting the loudspeaker gain to maximum and listening to the speaker. Typically you are going to hear 2 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 created by the wireless loudspeaker itself. After that compare several sets of wireless speakers according to the following rule: the lower the level of static, the higher the noise performance of the cordless speaker. Though, keep in mind that you have to put all sets of cordless loudspeakers to amplify by the same amount to evaluate different models.
If you favor a set of wireless loudspeakers with a small level of hissing, you may look at the signal-to-noise ratio number of the data sheet. A lot of makers will display this number. wireless loudspeakers with a large signal-to-noise ratio will output a small amount of noise. One of the reasons why cordless speakers produce noise is the fact that they utilize components like transistors and resistors which by nature produce noise. The overall noise is dependent on how much noise every element creates. However, the position of these components is also important. Components which are part of the loudspeaker built-in amp input stage are going to generally contribute the majority of the noise.
The wireless broadcast itself also creates hiss which is most noticable with types which utilize FM transmission at 900 MHz. Other cordless transmitters are going to interfer with FM type transmitters and create further static. For that reason the signal-to-noise ratio of FM type wireless loudspeakers varies depending on the distance of the speakers from the transmitter plus the level of interference. To avoid these problems, modern transmitters employ digital music transmission and generally transmit at 2.4 GHz or 5.8 GHz. The signal-to-noise ratio of digital transmitters depends mostly on the kind of analog-to-digital converters and other components which are utilized along with the resolution of the cordless protocol.
A lot of of recent wireless loudspeaker use amps which are based on a digital switching architecture. These amplifiers are named "class-D" or "class-T" amps. Switching amplifiers incorporate a power stage which is constantly switched at a frequency of approximately 400 kHz. In consequence, the output signal of wireless speaker switching amplifiers exhibit a rather big amount of switching noise. This noise component, however, is typically impossible to hear because it is well above 20 kHz. Though, it may still contribute to speaker distortion. Signal-to-noise ratio is typically only shown within the range of 20 Hz to 20 kHz. Therefore, a lowpass filter is utilized while measuring cordless loudspeaker amplifiers to eliminate the switching noise.
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 amp. The gain of the cordless speaker is set such that the full output wattage of the built-in amp can be realized. Next the noise-floor energy is calculated in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy.
One more convention to state the signal-to-noise ratio utilizes more subjective terms. These terms are "dBA" or "A weighted". You are going to discover these terms in most wireless loudspeaker parameter sheets. This method was developed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most responsive to signals around 1 kHz. Though, signals under 50 Hz and above 13 kHz are barely noticed. An A-weighted signal-to-noise ratio weighs the noise floor according to the human hearing and is generally higher than the unweighted signal-to-noise ratio.
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