Are you looking to acquire a new a set of cordless loudspeakers for your home? You might be dazzled by the amount of choices you have. In order to make an informed choice, it is best to familiarize yourself with common specs. One of these specs is known as "signal-to-noise ratio" and is not often understood. I am going to help explain the meaning of this term.
After you have narrowed down your search by taking a look at several basic criteria, such as the amount of output power, the dimensions of the loudspeakers and the cost, you are going to still have quite a few products to choose from. Now it is time to take a look at some of the technical specifications in more detail. The signal-to-noise ratio is a rather key parameter and shows how much noise or hiss the cordless loudspeaker produces.
Evaluating the noise level of different sets of wireless speakers may be done quite simply. Simply gather a couple of products which you wish to evaluate and short circuit the transmitter audio inputs. Next put the wireless speaker volume to maximum and check the level of noise by listening to the loudspeaker. The hiss which you hear is generated by the cordless loudspeaker itself. After that compare different sets of wireless speakers according to the next rule: the smaller the amount of static, the better the noise performance of the wireless loudspeaker. Yet, keep in mind that you must put all sets of wireless loudspeakers to amplify by the same level in order to compare several models.
In order to help you compare the noise performance, wireless speaker producers publish the signal-to-noise ratio in their cordless speaker specification sheets. Simply put, the larger the signal-to-noise ratio, the smaller the level of noise the cordless loudspeaker creates. Noise is created due to a number of factors. One factor is that today's wireless speakers all make use of elements like transistors as well as resistors. Those elements will create some amount of noise. Typically the components that are situated at the input stage of the built-in power amp are going to contribute most to the overall hiss. Therefore manufacturers generally are going to choose low-noise elements when designing the wireless loudspeaker amp input stage.
Another cause of noise is the cordless audio transmission itself. Usually models which employ FM type broadcast at 900 MHz will have a rather large level of hiss. FM transmitters are very prone to cordless interference which is why newer types typically utilize digital audio broadcast. The signal-to-noise ratio of digital transmitters is dependent mostly on the kind of analog-to-digital converters and other parts which are used along with the resolution of the cordless protocol.
The majority of recent cordless speakers use power amplifiers which are digital, also referred to as "class-d amplifiers". Class-D amplifiers make use of a switching stage which oscillates at a frequency between 300 kHz to 1 MHz. Because of this, the output signal of wireless loudspeaker switching amps contain a fairly large amount of switching noise. This noise component, though, is generally inaudible since it is well above 20 kHz. Nonetheless, it can still contribute to speaker distortion. Signal-to-noise ratio is generally only shown within the range of 20 Hz to 20 kHz. Thus, a lowpass filter is utilized while measuring wireless loudspeaker amps to eliminate the switching noise.
The most popular method for measuring the signal-to-noise ratio is to set the cordless loudspeaker to a gain that permits the maximum output swing. Next a test signal is fed into the transmitter. The frequency of this signal is generally 1 kHz. The amplitude of this signal is 60 dB below the full scale signal. Subsequently, only the noise in the range of 20 Hz and 20 kHz is considered. The noise at other frequencies is eliminated by a filter. Subsequently the level of the noise energy in relation to the full-scale output power is computed and shown in decibel.
Time and again you will discover the term "dBA" or "a-weighted" in your cordless loudspeaker spec sheet. A weighting is a technique of expressing the noise floor in a more subjective fashion. This technique was designed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most perceptive to signals around 1 kHz. Though, signals below 50 Hz and higher than 13 kHz are hardly noticed. The A-weighted signal-to-noise ratio is usually higher than the unweighted ratio and is shown in a lot of cordless speaker specification sheets.
After you have narrowed down your search by taking a look at several basic criteria, such as the amount of output power, the dimensions of the loudspeakers and the cost, you are going to still have quite a few products to choose from. Now it is time to take a look at some of the technical specifications in more detail. The signal-to-noise ratio is a rather key parameter and shows how much noise or hiss the cordless loudspeaker produces.
Evaluating the noise level of different sets of wireless speakers may be done quite simply. Simply gather a couple of products which you wish to evaluate and short circuit the transmitter audio inputs. Next put the wireless speaker volume to maximum and check the level of noise by listening to the loudspeaker. The hiss which you hear is generated by the cordless loudspeaker itself. After that compare different sets of wireless speakers according to the next rule: the smaller the amount of static, the better the noise performance of the wireless loudspeaker. Yet, keep in mind that you must put all sets of wireless loudspeakers to amplify by the same level in order to compare several models.
In order to help you compare the noise performance, wireless speaker producers publish the signal-to-noise ratio in their cordless speaker specification sheets. Simply put, the larger the signal-to-noise ratio, the smaller the level of noise the cordless loudspeaker creates. Noise is created due to a number of factors. One factor is that today's wireless speakers all make use of elements like transistors as well as resistors. Those elements will create some amount of noise. Typically the components that are situated at the input stage of the built-in power amp are going to contribute most to the overall hiss. Therefore manufacturers generally are going to choose low-noise elements when designing the wireless loudspeaker amp input stage.
Another cause of noise is the cordless audio transmission itself. Usually models which employ FM type broadcast at 900 MHz will have a rather large level of hiss. FM transmitters are very prone to cordless interference which is why newer types typically utilize digital audio broadcast. The signal-to-noise ratio of digital transmitters is dependent mostly on the kind of analog-to-digital converters and other parts which are used along with the resolution of the cordless protocol.
The majority of recent cordless speakers use power amplifiers which are digital, also referred to as "class-d amplifiers". Class-D amplifiers make use of a switching stage which oscillates at a frequency between 300 kHz to 1 MHz. Because of this, the output signal of wireless loudspeaker switching amps contain a fairly large amount of switching noise. This noise component, though, is generally inaudible since it is well above 20 kHz. Nonetheless, it can still contribute to speaker distortion. Signal-to-noise ratio is generally only shown within the range of 20 Hz to 20 kHz. Thus, a lowpass filter is utilized while measuring wireless loudspeaker amps to eliminate the switching noise.
The most popular method for measuring the signal-to-noise ratio is to set the cordless loudspeaker to a gain that permits the maximum output swing. Next a test signal is fed into the transmitter. The frequency of this signal is generally 1 kHz. The amplitude of this signal is 60 dB below the full scale signal. Subsequently, only the noise in the range of 20 Hz and 20 kHz is considered. The noise at other frequencies is eliminated by a filter. Subsequently the level of the noise energy in relation to the full-scale output power is computed and shown in decibel.
Time and again you will discover the term "dBA" or "a-weighted" in your cordless loudspeaker spec sheet. A weighting is a technique of expressing the noise floor in a more subjective fashion. This technique was designed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most perceptive to signals around 1 kHz. Though, signals below 50 Hz and higher than 13 kHz are hardly noticed. The A-weighted signal-to-noise ratio is usually higher than the unweighted ratio and is shown in a lot of cordless speaker specification sheets.
No comments:
Post a Comment