You may be overwhelmed by the number of wireless speakers available today. I will help narrow down your selection by taking a look at some of the key parameters which have a large effect on sound quality and speaker performance.
If you have a large house then adding speakers in other rooms may be a daunting task http://itsnews.co.uk/ . You may not want to drill holes in your walls to run speaker wires. As an alternative, wireless speakers promise ultimate freedom and ease of installation.
Wireless speakers are more complex than regular speakers. They incorporate an amplifier which will have an effect on speaker performance. The wireless receiver also has to be good quality and there is a large number of different technologies on the market.
Speakers come in different sizes and with different wattage. Typically the higher the wattage the louder the speaker. High-wattage speakers are required for outdoor applications or if you have a large room. The built-in amplifier as well as the drivers will determine how much power the speaker can handle. Speaker manufacturers will either provide maximum or RMS wattage ratings. RMS wattage is more objective than maximum wattage since it gives more clues about the actual amplifier power handling and amplifier power supply. Maximum wattage is often exaggerated by speaker manufacturers since the speaker can only sustain that amount of brief bursts of time.
Both RMS and maximum power ratings are important when comparing different models. The maximum power rating should be significantly higher than the RMS rating as music signals are of varying power and have large peaks.
Another important parameter is the speaker frequency response curve. Some manufacturers will publish the frequency response chart which is ideal for finding out how linear the speaker will reproduce audio over frequency and gives a good clue about speaker sound quality.
Harmonic distortion, also known as THD, will also affect the sound quality of the speaker. This term is either given in dB or in percent and tells how much the audio is changed from the original audio signal. The wireless receiver, audio amplifier and also the transducers contribute to distortion. Usually the higher the speaker is driven, the harmonic distortion of the speaker will increase. To allow easier comparison of different models, you want to look for harmonic distortion figures for different output power figures. At lower output power, the distortion is usually fairly low. As soon as the output power approaches maximum rated power, the audio signal will start clipping and the distortion will increase sharply. Also, the speaker transducers will be driven into nonlinear regions and thus make sure the speaker comes with high-quality drivers.
The quality of the built-in amplifier will have a great effect on sound quality and also power efficiency. Digital amplifiers by nature are much more efficient than Class-A or Class-AB amps. High efficiency amps eliminate heavy heat sinks and save electricity. Digital amps often have higher harmonic distortion than analog amps. This distortion is in part caused by the switching FET stage of the amp.
Wireless speakers often have several transducers. Each transducer is driven with a different part of the audio spectrum. The audio signal is split into different regions by using a crossover. Regular crossovers require fairly large and heavy components if the speaker has a high wattage. Alternatively, some models have separate amps, one for each driver. The audio signal can then be split into different regions by using small and low-cost components prior to the amplifier.