It is easy to be puzzled by the terminology that cordless speaker suppliers employ to depict the performance of their models. I will explain the meaning of one usually used specification: "signal-to-noise ratio" to help you make an informed decision when buying a new a set of cordless speakers.
Once you have narrowed down your search by looking at some key criteria, like the level of output power, 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 couple of the technical specs in more detail. Every cordless speaker is going to create a certain amount of hiss and hum. The signal-to-noise ratio will help calculate the amount of noise created by the loudspeaker.
You can do a simple assessment of the cordless loudspeaker noise by short circuiting the transmitter input, setting the loudspeaker gain to maximum and listening to the speaker. The static that you hear is produced by the wireless speaker itself. Be certain that the volume of each couple of cordless loudspeakers is set to the same level. Otherwise you will not be able to objectively compare the amount of static between different models. The general rule is: the lower the level of noise that you hear the better the noise performance.
While taking a look at the cordless loudspeaker spec sheet, you want to look for a set of wireless loudspeaker with a high signal-to-noise ratio figure which indicates that the cordless loudspeakers output a small amount of noise. Noise is created due to a number of factors. One factor is that today's wireless loudspeakers all employ components such as transistors as well as resistors. Those elements are going to produce some amount of hiss. As the built-in power amp overall noise performance is mostly determined by the performance of components situated at the amp input, suppliers are going to attempt to choose low-noise components while designing the amplifier input stage of their wireless speakers.
A further cause of hiss is the cordless audio transmission itself. Usually types which utilize FM type broadcast at 900 MHz are going to have a rather high amount of static. Other wireless transmitters will interfer with FM type transmitters and bring about further hiss. For that reason the signal-to-noise ratio of FM style wireless speakers changes depending on the distance of the loudspeakers from the transmitter and the amount of interference. To steer clear of these problems, modern transmitters use digital music broadcast and usually transmit at 2.4 GHz or 5.8 GHz. This kind of audio broadcast offers higher signal-to-noise ratio than analog style transmitters. The amount of noise depends on the resolution of the analog-to-digital converters as well as the quality of other components.
Most of recent cordless loudspeakers use power amplifiers which are digital, also referred to as "class-d amplifiers". Class-D amplifiers utilize a switching stage that oscillates at a frequency in the range of 300 kHz to 1 MHz. This switching frequency is also noise that is part of the amplified signal. Yet, latest cordless speakerspecifications generally only consider the noise between 20 Hz and 20 kHz.
Makers measure the signal-to-noise ratio by setting the built-in amplifier such that the full output swing may be achieved and by inputting a test signal to the transmitter that is typically 60 dB underneath the full scale of the speaker amp. Subsequently, the noise floor between 20 Hz and 20 kHz is measured and the ratio to the full-scale signal calculated. The noise signal at other frequencies is eliminated through a bandpass filter throughout this measurement.
Time and again the signal-to-noise ratio is expressed in a more subjective manner as "dbA" or "A weighted". This technique was designed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most sensitive to signals around 1 kHz. However, signals under 50 Hz and above 13 kHz are hardly heard. The A-weighted signal-to-noise ratio is typically larger than the unweighted ratio and is published in most cordless loudspeaker parameter sheets.
Once you have narrowed down your search by looking at some key criteria, like the level of output power, 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 couple of the technical specs in more detail. Every cordless speaker is going to create a certain amount of hiss and hum. The signal-to-noise ratio will help calculate the amount of noise created by the loudspeaker.
You can do a simple assessment of the cordless loudspeaker noise by short circuiting the transmitter input, setting the loudspeaker gain to maximum and listening to the speaker. The static that you hear is produced by the wireless speaker itself. Be certain that the volume of each couple of cordless loudspeakers is set to the same level. Otherwise you will not be able to objectively compare the amount of static between different models. The general rule is: the lower the level of noise that you hear the better the noise performance.
While taking a look at the cordless loudspeaker spec sheet, you want to look for a set of wireless loudspeaker with a high signal-to-noise ratio figure which indicates that the cordless loudspeakers output a small amount of noise. Noise is created due to a number of factors. One factor is that today's wireless loudspeakers all employ components such as transistors as well as resistors. Those elements are going to produce some amount of hiss. As the built-in power amp overall noise performance is mostly determined by the performance of components situated at the amp input, suppliers are going to attempt to choose low-noise components while designing the amplifier input stage of their wireless speakers.
A further cause of hiss is the cordless audio transmission itself. Usually types which utilize FM type broadcast at 900 MHz are going to have a rather high amount of static. Other wireless transmitters will interfer with FM type transmitters and bring about further hiss. For that reason the signal-to-noise ratio of FM style wireless speakers changes depending on the distance of the loudspeakers from the transmitter and the amount of interference. To steer clear of these problems, modern transmitters use digital music broadcast and usually transmit at 2.4 GHz or 5.8 GHz. This kind of audio broadcast offers higher signal-to-noise ratio than analog style transmitters. The amount of noise depends on the resolution of the analog-to-digital converters as well as the quality of other components.
Most of recent cordless loudspeakers use power amplifiers which are digital, also referred to as "class-d amplifiers". Class-D amplifiers utilize a switching stage that oscillates at a frequency in the range of 300 kHz to 1 MHz. This switching frequency is also noise that is part of the amplified signal. Yet, latest cordless speakerspecifications generally only consider the noise between 20 Hz and 20 kHz.
Makers measure the signal-to-noise ratio by setting the built-in amplifier such that the full output swing may be achieved and by inputting a test signal to the transmitter that is typically 60 dB underneath the full scale of the speaker amp. Subsequently, the noise floor between 20 Hz and 20 kHz is measured and the ratio to the full-scale signal calculated. The noise signal at other frequencies is eliminated through a bandpass filter throughout this measurement.
Time and again the signal-to-noise ratio is expressed in a more subjective manner as "dbA" or "A weighted". This technique was designed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most sensitive to signals around 1 kHz. However, signals under 50 Hz and above 13 kHz are hardly heard. The A-weighted signal-to-noise ratio is typically larger than the unweighted ratio and is published in most cordless loudspeaker parameter sheets.
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