Latest trends in wireless surround sound equipmentLatest-generation wireless audio products such as iPods, iPhones and wireless surround sound products promise to cut the cord while delivering crystal-clear audio. I will take a look at whether or not these products keep their claim to provide perfect-quality audio. Furthermore, I will look at the underlying technologies.
Some products come with wireless already built in while some others, in particular streaming audio products, frequently have optional wireless functionality. Most recent touch-screen iPods and iPhones already have WiFi and Bluetooth built in.
Bluetooth is relatively common as a low-cost wireless option. Still, Bluetooth does have some drawbacks. These weaknesses are frequently ignored but will have an effect on high-quality audio applications.
1) Inadequate operating range
Bluetooth devices usually just have a 30-foot range which limits Bluetooth to single-room applications.
2) Audio compression resulting from restricted data rate
Bluetooth reliably supports data transmission rates of around 1 Mbps only which is not adequate for uncompressed CD-quality audio. For that reason Bluetooth applies audio compression. The audio will be degraded to some extent because of the audio compression. For this reason higher-end audio equipment usually does not use Bluetooth wireless audio.
3) Audio delay
The audio will experience a delay of no less than 10 ms mostly due to the audio compression which is a dilemma for real-time audio applications but less critical for MP3 players.
4) Lacking multi-headphone support
Bluetooth can't stream to numerous headphones at the same time. This may be a dilemma in cases where several people like to listen to the same Bluetooth transmitter.
WiFi is another widely used wireless protocol that is also suitable for audio streaming. WiFi does support uncompressed audio but will have limitations broadcasting to a high number of wireless receivers simultaneously. As a consequence of the relatively high power consumption it is hardly ever utilized in wireless headphones however. WiFi is practical for streaming audio from a PC however because almost all PCs have WiFi access.
Wireless speakers and wireless amplifier products for home theater speakers typically employ their own proprietary protocol. Entry-level wireless headphones and speakers generally still use FM transmission which offers low cost but is prone to noise and audio degradation.
More advanced wireless protocols are based on digital formats which eliminate audio distortion and incorporate advanced features website including error correction to deal with interference from competing wireless devices.
Latest-generation wireless amplifiers employ uncompressed audio transmission. New protocols also allow streaming to an unlimited number of receivers. This allows whole-house audio distribution.
Some of these protocols support low-latency audio transmission which assures that the audio of all speakers will be in sync in a multi-channel application. These wireless audio transmitters generally work at 2.4 GHz. There are also some products such as Amphony’s line of wireless audio devices that operate at 5.8 GHz. Products that operate at 5.8 GHz have less competition from other wireless devices than those using the crowded 2.4 GHz frequency band.
Wireless amplifiers are available with different levels of audio quality, power consumption and standby power. Getting a high-quality low-distortion amplifier is essential for good sound quality. Wireless Class-D amplifiers typically have standby power of 5 Watts or less and a power efficiency of greater than 80% but sometimes high audio distortion. Choosing a low-distortion amplifier is essential. Good-quality wireless amplifiers have audio distortion of lower than 0.05%.