Are you searching to get a new a pair of wireless loudspeakers for your home? You may be dazzled by the amount of choices you have. In order to make an informed selection, it is best to familiarize yourself with common specs. One of these specifications is called “signal-to-noise ratio” and is not frequently understood. I will help explain the meaning of this term. As soon as you have narrowed down your search by looking at several key criteria, such as the level of output wattage, the dimensions of the speakers and the price, you are going to 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. The signal-to-noise ratio is a rather key specification and describes how much noise or hiss the wireless loudspeaker makes.
A method in order to accomplish a straightforward assessment of the noise performance of a set of wireless speakers is to short circuit the transmitter audio input and then to crank up the cordless loudspeaker to its utmost. Next listen to the speaker. The noise which you hear is created by the cordless speaker itself. Be certain that the volume of each pair of cordless speakers is couple to the same level. Otherwise you will not be able to objectively compare the level of hiss between different models. The general rule is: the lower the amount of hiss which you hear the better the noise performance.
If you favor a set of wireless loudspeakers with a small level of hissing, you can look at the signal-to-noise ratio number of the data sheet. The majority of manufacturers will show this number. cordless loudspeakers with a high signal-to-noise ratio will output a small amount of noise. There are a number of reasons why wireless speakers introduced at http://www.amphony.com/products/wireless-speaker.htm are going to add some form of noise or other unwanted signal. Transistors and resistors that are part of each modern wireless speaker by nature produce noise. The overall noise is dependent on how much hiss every component generates. Nonetheless, the location of these elements is also significant. Components which are part of the loudspeaker built-in amplifier input stage are going to generally contribute the majority of the noise.
Noise is also created by the cordless transmission. Different styles of transmitters are available that work at different frequencies. The most inexpensive sort of transmitters employs FM transmission and commonly broadcasts at 900 MHz. FM transmitters are extremely prone to cordless interference which is why newer types usually employ digital music broadcast. This kind of audio transmission provides better signal-to-noise ratio than analog type transmitters. The amount of hiss is dependent on the resolution of the analog-to-digital converters as well as the quality of other parts. Most of modern cordless loudspeaker use amplifiers which are based on a digital switching topology. These amplifiers are named “class-D” or “class-T” amplifiers. Switching amps include a power stage that is constantly switched at a frequency of around 400 kHz. This switching frequency is also hiss that is part of the amplified signal. On the other hand, latest wireless loudspeakerspecifications usually only consider the hiss between 20 Hz and 20 kHz. The most common method for measuring the signal-to-noise ratio is to couple the wireless loudspeaker to a gain which allows the maximum output swing. Then a test tone is fed into the transmitter. The frequency of this tone is generally 1 kHz. The amplitude of this tone is 60 dB below the full scale signal. After that, only the noise between 20 Hz and 20 kHz is considered. The noise at different frequencies is removed by a filter. Next the amount of the noise energy in relation to the full-scale output wattage is calculated and shown in decibel. Frequently the signal-to-noise ratio is expressed in a more subjective manner as “dbA” or “A weighted”. In other words, this method attempts to state how the noise is perceived by a human. Human hearing is most sensitive to signals around 1 kHz whereas signals under 50 Hz and above 14 kHz are barely noticed. The A-weighted signal-to-noise ratio is typically higher than the unweighted ratio and is published in the majority of cordless speaker spec sheets.