A Couple Of Technical Suggestions For Buying A Set Of Wireless Speakers

Are you searching to get a new a pair of wireless speakers for your home? You might be dazzled by the number of choices you have. In order to make an informed choice, it is best to familiarize yourself with frequent terms. One of these specs is referred to as "signal-to-noise ratio" and is not often understood. I am going to help clarify the meaning of this expression.

As soon as you have narrowed down your search by looking at several basic criteria, like the level of output wattage, the size of the loudspeakers plus the price, you are going to still have quite a few products to choose from. Now it is time to take a look at a couple of the technical specifications in more detail. One important parameter of cordless speakers is the signal-to-noise ratio. To put it simply, the signal-to-noise ratio describes how much hum or hiss the loudspeakers are going to add to the audio signal. This ratio is typically described in decibel or "db" for short.

A technique in order to do a straightforward assessment of the noise performance of a couple of wireless speakers is to short circuit the transmitter audio input and then to crank up the cordless speaker to its maximum. Next listen to the speaker. Typically you will hear 2 components. The first is hissing. In addition, you are going to regularly hear a hum at 50 or 60 Hz. Both of these are components which are generated by the wireless loudspeaker itself. After that compare different sets of cordless speakers according to the following rule: the lower the level of hiss, the better the noise performance of the wireless loudspeaker. However, keep in mind that you must put all sets of wireless loudspeakers to amplify by the same amount in order to compare different models.

If you prefer a set of wireless loudspeakers with a small level of hissing, you may look at the signal-to-noise ratio number of the data sheet. Most suppliers are going to publish this number. wireless loudspeakers with a high signal-to-noise ratio will output a small amount of static. One of the reasons why cordless loudspeakers make noise is the fact that they use components including transistors as well as resistors that by nature produce noise. Since the built-in power amp overall noise performance is mostly determined by the performance of components located at the amplifier input, makers are going to try to choose low-noise components while developing the amplifier input stage of their cordless loudspeakers.

An additional cause of static is the cordless music broadcast itself. Usually types that utilize FM type transmission at 900 MHz are going to have a fairly high amount of static. The amount of noise is also dependent upon the level of cordless interference from other transmitters. Newer types will normally employ digital audio broadcast at 2.4 GHz or 5.8 GHz. The signal-to-noise ratio of digital transmitters depends mostly on the type of analog-to-digital converters and other parts that are utilized and also the resolution of the cordless protocol.

The majority of modern cordless loudspeakers use power amps which are digital, also referred to as "class-d amplifiers". Class-D amplifiers utilize a switching stage which oscillates at a frequency in the range of 300 kHz to 1 MHz. This switching noise can result in a certain level of speaker distortion yet is generally not included in the signal-to-noise ratio which only considers noise between 20 Hz and 20 kHz.

The most common method for measuring the signal-to-noise ratio is to set the cordless loudspeaker to a gain that enables the maximum output swing. Subsequently a test signal is fed into the transmitter. The frequency of this signal is generally 1 kHz. The amplitude of this tone is 60 dB below the full scale signal. Next, the noise floor between 20 Hz and 20 kHz is calculated and the ratio to the full-scale signal calculated. The noise signal at different frequencies is removed via a bandpass filter during this measurement.

Time and again the signal-to-noise ratio is shown in a more subjective way as "dbA" or "A weighted". This method tries to evaluate in how far the cordless speaker 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 magnify the noise floor for frequencies that are easily perceived and suppress the noise floor at frequencies which are hardly perceived. A lot of cordless speaker will have a larger A-weighted signal-to-noise ratio than the un-weighted ratio.