Things To Realize About Wireless Speaker Power Efficiency

By Michelle Jaeger


When you are ready to purchase brand new wireless speakers, you might be wondering how efficiently your wireless loudspeakers function. I'll reveal precisely what the term "power efficiency" stands for and also why you must take a closer look at this figure in your selection of brand new wireless loudspeakers.

Low-efficiency models demand more overall energy to create the same level of audio power as high-efficiency products. Thus they need a larger power source which makes the wireless speakers more expensive to build. Additionally, the thermal stress on the circuit board elements as well as amp materials is much more severe and may even decrease the reliability.

Given that low-efficiency wireless loudspeakers are going to deliver only a small percentage of the power consumed by the amp as usable audio power, the amplifier requires a bigger power source than high-efficiency types leading to higher cost. An increased amount of heat causes additional stress on elements. The life expectancy of the cordless speakers might be decreased and reliability might be jeopardized. High-efficiency wireless speakers in contrast tend not to suffer from these problems and can be built really small.

The efficiency is shown as a percentage in the cordless speakers data sheet. Various amp topologies provide different power efficiencies. Class-A amplifiers are usually the least efficient and Class-D the most efficient. Normal power efficiencies range from 25% to 98%. From the efficiency percentage you'll be able to work out just how much energy the amplifier will squander. An amplifier which has a 50% power efficiency will squander 50 % of the used energy. An amplifier with 90% efficiency will waste 10%.

What is less known about efficiency is the fact that this figure isn't fixed. Actually it differs depending on how much power the amplifier provides. Therefore occasionally you will find efficiency figures for various energy levels within the data sheet. Given that each amplifier will need a specific level of power, irrespective of the level of power the amp delivers to the loudspeakers, the amplifier power efficiency is higher the more power the amp provides and is normally specified for the greatest power the amplifier can handle. The measurement setup of amplifier power efficiency uses a power resistor which is attached to the amplifier. The amp is being fed a constant-envelope sine-wave signal. Then the energy absorbed by the resistor is tested and divided by the power the amp consumes. To get a full power efficiency profile, the audio power of the amplifier is swept between different values. At each value the efficiency is calculated and plotted onto a chart.

While switching (Class-D) amplifiers possess amongst the highest power efficiency, they tend to possess higher music distortion than analog audio amplifiers and smaller signal-to-noise ratio. As a result you are going to need to weigh the size of the cordless speakers against the sound fidelity. Then again, digital amps have come a long way and are offering better music fidelity than in the past. Wireless speakers which make use of Class-T amps come close to the audio fidelity of models which have analog amplifiers. Subsequently choosing a couple of cordless loudspeakers which utilize switching amplifier with great music fidelity is now feasible.




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