It is easy to be puzzled by the terminology which cordless speaker makers utilize in order to explain the performance of their models. I will explain the meaning of a usually used spec: „signal-to-noise ratio“ to help you make an informed choice whilst getting a brand new a couple of cordless speakers.
When you have narrowed down your search by looking at a few fundamental criteria, like 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 take a look at a couple of the technical specifications in more detail. The signal-to-noise ratio is a rather important parameter and explains how much noise or hiss the cordless speaker makes.
You can make a straightforward comparison of the wireless loudspeaker noise by short circuiting the transmitter input, setting the loudspeaker volume to maximum and listening to the loudspeaker. The noise that you hear is generated by the cordless speaker itself. Next compare several sets of cordless loudspeakers according to the following rule: the lower the amount of static, the better the noise performance of the wireless speaker. Yet, keep in mind that you have to put all sets of cordless loudspeakers to amplify by the same level to evaluate different models. To help you compare the noise performance, cordless speaker manufacturers show the signal-to-noise ratio in their cordless loudspeaker specification sheets. Simply put, the larger the signal-to-noise ratio, the lower the level of noise the wireless loudspeaker produces. There are a number of reasons why wireless loudspeakers will add some form of noise or other unwanted signal. Transistors and resistors that are part of each modern wireless speaker by nature generate noise. Typically the components which are situated at the input stage of the built-in power amplifier will contribute most to the overall hiss. Consequently manufacturers typically are going to select low-noise components while designing the wireless speaker amplifier input stage.
Static is also created by the cordless transmission. Different types of transmitters are available that work at different frequencies. The least expensive sort of transmitters employs FM transmission and generally transmits at 900 MHz. If you liked this article and you would like to obtain more info concerning outdoor bluetooth wireless speakers kindly see our own web-page. FM transmitters are extremely prone to cordless interference which is why newer types typically use digital music broadcast. The signal-to-noise ratio of digital transmitters is independent from the distance of the wireless speakers. It is determined by how the audio signal is sampled. Furthermore, the quality of components inside the transmitter will influence the signal-to-noise ratio. A lot of of recent wireless speaker use amps which are based on a digital switching topology. These amplifiers are known as „class-D“ or „class-T“ amps. Switching amplifiers incorporate a power stage that is constantly switched at a frequency of around 400 kHz. Because of this, the output signal of wireless loudspeaker switching amplifiers exhibit a rather big level of switching noise. This noise component, however, is typically inaudible as it is well above 20 kHz. However, it can still contribute to speaker distortion. Signal-to-noise ratio is generally only shown within the range of 20 Hz to 20 kHz. As a result, a lowpass filter is utilized while measuring cordless speaker amplifiers to eliminate the switching noise.
The signal-to-noise ratio is measured by inputting a 1 kHz test tone 60 dB underneath the full scale and measuring the noise floor of the signal generated by the built-in amplifier. The volume of the cordless loudspeaker is couple such that the full output power of the built-in amplifier can be achieved. Subsequently the noise-floor energy is calculated in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy. Often you are going to find the term „dBA“ or „a-weighted“ in your wireless speaker specification sheet. A weighting is a technique of showing the noise floor in a more subjective manner. 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. On the other hand, signals below 50 Hz and higher than 13 kHz are barely heard. The A-weighted signal-to-noise ratio is usually higher than the unweighted ratio and is shown in a lot of cordless speaker parameter sheets.