The newest range of wireless audio transmitter products claims streaming of music throughout the home without limits. We will take a look at the most common technologies for wireless audio and give some tips for selecting the best wireless audio product.

If your residence is not wired for audio then you face quite a problem when you want to get your music from your living room to your bedroom. Frequently the audio source cannot be moved. Running speaker wires between rooms will be costly and therefore a lot of people are searching for alternatives. Products which resolve this problem are commonly based on the following technologies: infrared wireless, RF wireless, wireless LAN or powerline.

Infrared products send the audio as lightwaves. Light cannot go through walls. As a result devices utilizing infrared, such as wireless surround sound kits, are limited to a single room.

RF wireless products send the music as RF waves - either by using FM transmission or digital transmission - and can as a result easily transmit through walls. FM transmission is cheap but rather prone to noise, audio distortion and susceptible to interference.

Products which use digital wireless audio transmission employ a digital protocol. Such devices include transmitters from Amphony. In this protocol, prior to transmission the audio signal is converted to digital data. This method ensures that the audio quality is completely maintained. Some transmitters employ some type of audio compression, such as Bluetooth transmitters, which will degrade the audio to some degree. Transmitters which send the audio data uncompressed will achieve the maximum fidelity.

Products utilizing wireless LAN are useful when streaming audio from a PC. Their drawback is that they normally have some fairly high latency, i.e. the signal will be delayed by some amount since wireless LAN was not specifically designed for real-time audio streaming. WLAN receivers typically require purchasing a separate LAN card to be plugged into every receiver.

Powerline products utilize the power mains as a medium to send the audio. These products usually offer excellent range. On the other hand, they face problems if there are a number of separate mains circuits in the home. In this situation the signal will have difficulty crossing between these circuits. Also, these products build in a delay of a number of seconds to safeguard against transmission errors during power surges and spikes which prevents their use in applications where the audio from wireless loudspeakers has to be in sync with other non-wireless speakers or video.

Now we'll give you some pointers for shopping for a wireless system: Select a system that supports multiple wireless receivers if you plan to stream audio to a number of rooms so that you don't have to buy a separate transmitter for every receiver. Picking a product with some form of error correction will help mitigate against strong RF interference. Such interference can be caused by other wireless transmitters. Pick a digital RF audio transmitter to make sure that the audio quality is maintained. Make sure the audio delay is less than 10 ms if you have a real-time application such as video.

Select a transmitter that has all the audio inputs you require, such as speaker inputs, line-level RCA inputs etc. Pick a system where you can add receivers later on which offer all of the necessary outputs, e.g. amplified speaker outputs, RCA outputs etc. Choose a transmitter that can adjust the audio volume of the input stage. This will give you the versatility to connect the transmitter to any type of equipment with different signal levels. Otherwise the audio may get clipped inside the transmitter converter stage or the dynamic range is not fully used.

Ensure that the system provides amplified receivers with a digital amplifier to guarantee high power efficiency. This will help keep the receiver cool during operation. Also, make sure the amplifier offers low audio distortion. This is vital for good sound quality. Select a system which offers receivers that can drive speakers with the desired Ohm rating. Make sure the receivers have a small form factor and are easily mountable. This will help during the set up. Devices which function in the 5.8 GHz frequency band will have less trouble with wireless interference than devices utilizing the crowded 900 MHz or 2.4 GHz frequency band.