Latest-generation wireless audio products such as iPods, iPhones and wireless surround sound products promise to cut the cord while delivering crystal-clear audio. We will look at some of the most recent products to find out which applications they work for.

Some products come with wireless already built in while others, in particular streaming audio products, often have optional wireless capability. Newest touch-screen iPods and iPhones already have WiFi and Bluetooth built in.

Bluetooth is fairly common as a low-cost wireless solution. However, Bluetooth does have some drawbacks. These weaknesses are often overlooked but will have an impact on high-quality audio applications.

1) Short range

The range of Bluetooth devices is typically only 30 ft. This excludes Bluetooth from multi-room applications.

2) Limited data transmission capacity

Bluetooth will apply audio compression since it does not reliably offer a high-enough data rate for uncompressed audio. Audio compression will degrade the audio quality to some extent. High-quality audio transmission typically does not tolerate this type of degradation. Therefore Bluetooth is normally not used in high-end audio products.

3) Audio delay

The audio will experience a delay of at least 10 ms mostly due to the audio compression which is a problem for real-time audio applications but less critical for MP3 players.

4) No support of multiple headphones

Bluetooth cannot stream to multiple headphones at the same time. This may be a problem in cases where several people want to listen to the same Bluetooth transmitter.

Another common protocol is WiFi which supports uncompressed audio but also has problems simultaneously streaming to multiple receivers. It is convenient for streaming music from a PC due to the high availability but is normally not used in wireless headphone products due to the relatively high power consumption of WiFi. Read the rest of this entry »