Are you looking to buy a brand new amp for your home speakers? You may be dazzled by the number of choices you have. To make an informed selection, it is best to familiarize yourself with common terms. One of these specs is called "signal-to-noise ratio" and is not often understood. I am going to help explain the meaning of this expression. After you have narrowed down your search by looking at several fundamental criteria, like the level of output power, the size of the amplifier and the price, you are going to still have quite a few models to choose from. Now it is time to take a look at some of the technical specifications in more detail. Every amplifier is going to make a certain amount of hiss as well as hum. The signal-to-noise ratio will help calculate the level of noise produced by the amplifier.
As soon as you have selected a number of amplifiers, it's time to explore some of the specifications in more detail in order to help you narrow down your search to one model. The signal-to-noise ratio is a fairly important spec and describes how much noise or hiss the amplifier makes.
In order to help you compare the noise performance, amplifier manufacturers publish the signal-to-noise ratio in their amplifier spec sheets. Simply put, the larger the signal-to-noise ratio, the smaller the amount of noise the amplifier creates. There are a number of reasons why power amplifiers will add some form of hiss or other unwanted signal. Transistors and resistors that are part of each modern amplifier by nature produce noise. Given that the amplifier overall noise performance is mostly determined by the performance of components located at the amplifier input, manufacturers will attempt to select low-noise components while developing the amplifier input stage.
The majority of today's power amps are digital amplifiers, also known as "class-d amplifiers". Class-D amps utilize a switching stage which oscillates at a frequency between 300 kHz to 1 MHz. This switching noise can cause a certain amount of speaker distortion but is usually not included in the the signal-to-noise ratio which merely considers noise between 20 Hz and 20 kHz.
The majority of today's power amplifiers include a wattage switching stage that switches at a frequency around 500 kHz. Consequently, the output signal of switching amps exhibit a fairly big amount of switching noise. This noise component, though, is typically inaudible because it is well above 20 kHz. On the other hand, it may still contribute to speaker distortion. Signal-to-noise ratio is typically only shown within the range of 20 Hz to 20 kHz. As a result, a lowpass filter is utilized when measuring switching amplifiers in order to remove the switching noise. Producers measure the signal-to-noise ratio by setting the amplifier such that the full output swing may be achieved and by feeding a test signal to the amp which is typically 60 dB below the full scale of the amplifier. Then the noise-floor energy is measured in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy.
Another convention in order to express the signal-to-noise ratio utilizes more subjective terms. These terms are "dBA" or "A weighted". You are going to spot these terms in most amp parameter sheets. This method was designed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most perceptive to signals around 1 kHz. Then again, signals below 50 Hz and above 13 kHz are hardly noticed. An A-weighted signal-to-noise ratio weighs the noise floor in accordance to the human hearing and is normally higher than the unweighted signal-to-noise ratio.
As soon as you have selected a number of amplifiers, it's time to explore some of the specifications in more detail in order to help you narrow down your search to one model. The signal-to-noise ratio is a fairly important spec and describes how much noise or hiss the amplifier makes.
In order to help you compare the noise performance, amplifier manufacturers publish the signal-to-noise ratio in their amplifier spec sheets. Simply put, the larger the signal-to-noise ratio, the smaller the amount of noise the amplifier creates. There are a number of reasons why power amplifiers will add some form of hiss or other unwanted signal. Transistors and resistors that are part of each modern amplifier by nature produce noise. Given that the amplifier overall noise performance is mostly determined by the performance of components located at the amplifier input, manufacturers will attempt to select low-noise components while developing the amplifier input stage.
The majority of today's power amps are digital amplifiers, also known as "class-d amplifiers". Class-D amps utilize a switching stage which oscillates at a frequency between 300 kHz to 1 MHz. This switching noise can cause a certain amount of speaker distortion but is usually not included in the the signal-to-noise ratio which merely considers noise between 20 Hz and 20 kHz.
The majority of today's power amplifiers include a wattage switching stage that switches at a frequency around 500 kHz. Consequently, the output signal of switching amps exhibit a fairly big amount of switching noise. This noise component, though, is typically inaudible because it is well above 20 kHz. On the other hand, it may still contribute to speaker distortion. Signal-to-noise ratio is typically only shown within the range of 20 Hz to 20 kHz. As a result, a lowpass filter is utilized when measuring switching amplifiers in order to remove the switching noise. Producers measure the signal-to-noise ratio by setting the amplifier such that the full output swing may be achieved and by feeding a test signal to the amp which is typically 60 dB below the full scale of the amplifier. Then the noise-floor energy is measured in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy.
Another convention in order to express the signal-to-noise ratio utilizes more subjective terms. These terms are "dBA" or "A weighted". You are going to spot these terms in most amp parameter sheets. This method was designed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most perceptive to signals around 1 kHz. Then again, signals below 50 Hz and above 13 kHz are hardly noticed. An A-weighted signal-to-noise ratio weighs the noise floor in accordance to the human hearing and is normally higher than the unweighted signal-to-noise ratio.
About the Author:
Click to find out more information on surround sound amplifiers. On top of that, pay a visit to http://ecarhifi.com/.
No comments:
Post a Comment