It is easy to be perplexed by the terminology which wireless speaker manufacturers employ in order to express the performance of their products. I will explain the meaning of one regularly utilized spec: "signal-to-noise ratio" to help you make an informed decision when buying a brand new a set of cordless loudspeakers.
When you have narrowed down your search by looking at a few basic criteria, including the level of output wattage, the dimensions of the loudspeakers as well as the price, you will still have quite a few models to choose from. Now it is time to look at a few of the technical specifications in more detail. Every cordless loudspeaker will create a certain amount of hiss as well as hum. The signal-to-noise ratio is going to help calculate the level of static created by the loudspeaker.
You can make a simple assessment of the cordless loudspeaker noise by short circuiting the transmitter input, setting the speaker volume to maximum and listening to the loudspeaker. You will hear some amount of hissing and/or hum coming from the loudspeaker. This hiss is produced by the wireless loudspeaker itself. Make sure that the gain of each couple of wireless loudspeakers is pair to the same amount. Otherwise you will not be able to objectively compare the level of noise between different models. The general rule is: the smaller the level of noise which you hear the better the noise performance.
In order to help you evaluate the noise performance, cordless speaker suppliers show the signal-to-noise ratio in their wireless speaker specification sheets. Simply put, the higher the signal-to-noise ratio, the smaller the amount of noise the wireless speaker creates. One of the reasons why wireless speakers generate noise is the fact that they utilize components like transistors as well as resistors that by nature generate noise. Typically the elements that are located at the input stage of the built-in power amplifier will contribute most to the overall hiss. Thus manufacturers usually will pick low-noise components whilst developing the cordless speaker amp input stage.
Noise is also brought on by the wireless transmission. Different kinds of transmitters are available which operate at different frequencies. The most inexpensive sort of transmitters employs FM transmission and usually transmits at 900 MHz. The amount of noise is also dependent upon the level of wireless interference from other transmitters. Newer models are going to generally make use of digital audio broadcast at 2.4 GHz or 5.8 GHz. The signal-to-noise ratio of digital transmitters depends by and large on the type of analog-to-digital converters and other components that are utilized and also the resolution of the wireless protocol.
Most of today's wireless speaker use amplifiers which are based on a digital switching architecture. These amplifiers are referred to as "class-D" or "class-T" amplifiers. Switching amps incorporate a power stage which is continuously switched at a frequency of around 400 kHz. This switching noise can result in a certain level of loudspeaker distortion yet is generally not included in the signal-to-noise ratio which merely considers noise in the range of 20 Hz and 20 kHz.
The most widespread method for measuring the signal-to-noise ratio is to couple the cordless speaker to a gain which enables the maximum output swing. Subsequently a test tone is input into the transmitter. The frequency of this signal is generally 1 kHz. The amplitude of this signal is 60 dB underneath the full scale signal. Then, 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 eliminated via a bandpass filter throughout this measurement.
A different convention in order to express the signal-to-noise ratio employs more subjective terms. These terms are "dBA" or "A weighted". You will find these terms in a lot of wireless loudspeaker parameter sheets. In other words, this method tries to state how the noise is perceived by a human. Human hearing is most perceptive to signals around 1 kHz while signals under 50 Hz and higher than 14 kHz are hardly noticed. The A-weighted signal-to-noise ratio is typically higher than the unweighted ratio and is shown in the majority of cordless loudspeaker parameter sheets.
When you have narrowed down your search by looking at a few basic criteria, including the level of output wattage, the dimensions of the loudspeakers as well as the price, you will still have quite a few models to choose from. Now it is time to look at a few of the technical specifications in more detail. Every cordless loudspeaker will create a certain amount of hiss as well as hum. The signal-to-noise ratio is going to help calculate the level of static created by the loudspeaker.
You can make a simple assessment of the cordless loudspeaker noise by short circuiting the transmitter input, setting the speaker volume to maximum and listening to the loudspeaker. You will hear some amount of hissing and/or hum coming from the loudspeaker. This hiss is produced by the wireless loudspeaker itself. Make sure that the gain of each couple of wireless loudspeakers is pair to the same amount. Otherwise you will not be able to objectively compare the level of noise between different models. The general rule is: the smaller the level of noise which you hear the better the noise performance.
In order to help you evaluate the noise performance, cordless speaker suppliers show the signal-to-noise ratio in their wireless speaker specification sheets. Simply put, the higher the signal-to-noise ratio, the smaller the amount of noise the wireless speaker creates. One of the reasons why wireless speakers generate noise is the fact that they utilize components like transistors as well as resistors that by nature generate noise. Typically the elements that are located at the input stage of the built-in power amplifier will contribute most to the overall hiss. Thus manufacturers usually will pick low-noise components whilst developing the cordless speaker amp input stage.
Noise is also brought on by the wireless transmission. Different kinds of transmitters are available which operate at different frequencies. The most inexpensive sort of transmitters employs FM transmission and usually transmits at 900 MHz. The amount of noise is also dependent upon the level of wireless interference from other transmitters. Newer models are going to generally make use of digital audio broadcast at 2.4 GHz or 5.8 GHz. The signal-to-noise ratio of digital transmitters depends by and large on the type of analog-to-digital converters and other components that are utilized and also the resolution of the wireless protocol.
Most of today's wireless speaker use amplifiers which are based on a digital switching architecture. These amplifiers are referred to as "class-D" or "class-T" amplifiers. Switching amps incorporate a power stage which is continuously switched at a frequency of around 400 kHz. This switching noise can result in a certain level of loudspeaker distortion yet is generally not included in the signal-to-noise ratio which merely considers noise in the range of 20 Hz and 20 kHz.
The most widespread method for measuring the signal-to-noise ratio is to couple the cordless speaker to a gain which enables the maximum output swing. Subsequently a test tone is input into the transmitter. The frequency of this signal is generally 1 kHz. The amplitude of this signal is 60 dB underneath the full scale signal. Then, 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 eliminated via a bandpass filter throughout this measurement.
A different convention in order to express the signal-to-noise ratio employs more subjective terms. These terms are "dBA" or "A weighted". You will find these terms in a lot of wireless loudspeaker parameter sheets. In other words, this method tries to state how the noise is perceived by a human. Human hearing is most perceptive to signals around 1 kHz while signals under 50 Hz and higher than 14 kHz are hardly noticed. The A-weighted signal-to-noise ratio is typically higher than the unweighted ratio and is shown in the majority of cordless loudspeaker parameter sheets.
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