It is easy to be confused by the terminology that cordless loudspeaker makers employ to depict the performance of their products. I am going to explain the meaning of one regularly used spec: "signal-to-noise ratio" in order to help you make an informed decision whilst getting a brand new a pair of cordless speakers.
After you have narrowed down your search by looking at some fundamental criteria, including the amount of output wattage, the dimensions of the loudspeakers plus the cost, you are going to still have quite a few products to choose from. Now it is time to look at some of the technical specs in more detail. The signal-to-noise ratio is a fairly important specification and describes how much noise or hiss the wireless speaker makes.
Comparing the noise level of several sets of cordless speakers can be accomplished fairly simply. Just collect a couple of versions which you want to compare and short circuit the transmitter audio inputs. Afterward put the cordless loudspeaker volume to maximum and verify the amount of static by listening to the speaker. You are going to hear some amount of hissing and/or hum coming from the speaker. This noise is produced by the cordless speaker itself. Make certain that the volume of each couple of wireless speakers is set to the same amount. Otherwise you will not be able to objectively compare the amount of noise between different models. The general rule is: the smaller the level of hiss which you hear the higher the noise performance.
While taking a look at the cordless speaker spec sheet, you want to look for a set of wireless loudspeaker with a large signal-to-noise ratio figure which suggests that the cordless loudspeakers output a small amount of noise. Noise is generated due to several reasons. One factor is that modern wireless loudspeakers all employ components such as transistors as well as resistors. Those components are going to produce some amount of hiss. Typically the components which are situated at the input stage of the built-in power amplifier will contribute most to the overall noise. Consequently producers usually will pick low-noise elements whilst designing the wireless loudspeaker amp input stage.
A different cause of static is the cordless music broadcast itself. Normally products which make use of FM style broadcast at 900 MHz are going to have a rather high level of noise. FM transmitters are quite prone to cordless interference which is why newer products usually utilize digital music broadcast. This style of music transmission offers higher signal-to-noise ratio than analog type transmitters. The level of static is dependent on the resolution of the analog-to-digital converters in addition to the quality of other components.
The majority of of recent wireless speaker use amplifiers which are based on a digital switching topology. These amplifiers are called "class-D" or "class-T" amps. Switching amps incorporate a power stage which is always switched at a frequency of approximately 400 kHz. This switching frequency is also noise that is part of the amplified signal. However, latest cordless loudspeakerspecifications generally only consider the noise between 20 Hz and 20 kHz.
Producers measure the signal-to-noise ratio by means of setting the built-in amplifier such that the full output swing can be achieved and by feeding a test signal to the transmitter which is normally 60 dB below the full scale of the loudspeaker amplifier. Next 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 will find the expression "dBA" or "a-weighted" in your wireless loudspeaker parameter sheet. A weighting is a method of showing the noise floor in a more subjective way. This technique tries to examine in how far the cordless loudspeaker noise is perceived by human hearing which is most sensitive to signals at frequencies at 1 kHz. As a result an A-weighting filter will amplify the noise floor for frequencies that are easily perceived and suppress the noise floor at frequencies which are barely heard. Most cordless loudspeaker will show a higher A-weighted signal-to-noise ratio than the un-weighted ratio.
After you have narrowed down your search by looking at some fundamental criteria, including the amount of output wattage, the dimensions of the loudspeakers plus the cost, you are going to still have quite a few products to choose from. Now it is time to look at some of the technical specs in more detail. The signal-to-noise ratio is a fairly important specification and describes how much noise or hiss the wireless speaker makes.
Comparing the noise level of several sets of cordless speakers can be accomplished fairly simply. Just collect a couple of versions which you want to compare and short circuit the transmitter audio inputs. Afterward put the cordless loudspeaker volume to maximum and verify the amount of static by listening to the speaker. You are going to hear some amount of hissing and/or hum coming from the speaker. This noise is produced by the cordless speaker itself. Make certain that the volume of each couple of wireless speakers is set to the same amount. Otherwise you will not be able to objectively compare the amount of noise between different models. The general rule is: the smaller the level of hiss which you hear the higher the noise performance.
While taking a look at the cordless speaker spec sheet, you want to look for a set of wireless loudspeaker with a large signal-to-noise ratio figure which suggests that the cordless loudspeakers output a small amount of noise. Noise is generated due to several reasons. One factor is that modern wireless loudspeakers all employ components such as transistors as well as resistors. Those components are going to produce some amount of hiss. Typically the components which are situated at the input stage of the built-in power amplifier will contribute most to the overall noise. Consequently producers usually will pick low-noise elements whilst designing the wireless loudspeaker amp input stage.
A different cause of static is the cordless music broadcast itself. Normally products which make use of FM style broadcast at 900 MHz are going to have a rather high level of noise. FM transmitters are quite prone to cordless interference which is why newer products usually utilize digital music broadcast. This style of music transmission offers higher signal-to-noise ratio than analog type transmitters. The level of static is dependent on the resolution of the analog-to-digital converters in addition to the quality of other components.
The majority of of recent wireless speaker use amplifiers which are based on a digital switching topology. These amplifiers are called "class-D" or "class-T" amps. Switching amps incorporate a power stage which is always switched at a frequency of approximately 400 kHz. This switching frequency is also noise that is part of the amplified signal. However, latest cordless loudspeakerspecifications generally only consider the noise between 20 Hz and 20 kHz.
Producers measure the signal-to-noise ratio by means of setting the built-in amplifier such that the full output swing can be achieved and by feeding a test signal to the transmitter which is normally 60 dB below the full scale of the loudspeaker amplifier. Next 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 will find the expression "dBA" or "a-weighted" in your wireless loudspeaker parameter sheet. A weighting is a method of showing the noise floor in a more subjective way. This technique tries to examine in how far the cordless loudspeaker noise is perceived by human hearing which is most sensitive to signals at frequencies at 1 kHz. As a result an A-weighting filter will amplify the noise floor for frequencies that are easily perceived and suppress the noise floor at frequencies which are barely heard. Most cordless loudspeaker will show a higher A-weighted signal-to-noise ratio than the un-weighted ratio.
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