Getting audio from your living room to your bed room can be quite a challenge particularly in buildings which are not wired for audio. Products which resolve this problem are commonly based on the following technologies: infrared wireless, RF wireless, wireless LAN or powerline.
Infrared is restricted to line of sight since the audio signal is broadcast as lightwaves and as a result products utilizing this technology, such as infrared wireless surround sound products, are restricted to a single room.
RF wireless products broadcast the music as RF waves – either by using FM transmission or digital transmission – and can therefore easily transmit through walls. FM transmission is inexpensive but quite prone to hiss, audio distortion and susceptible to interference.
Products which utilize digital wireless audio transmission use a digital protocol. Such products include transmitters from Amphony. In this protocol, before transmission the audio signal is converted to digital data. This method guarantees that the audio quality is completely maintained. Some transmitters employ some sort 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 using wireless LAN are useful when streaming audio from a PC. Their drawback is that they typically 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 frequently do not have built-in network access. As a result, such products often require purchasing separate LAN cards. These cards are then plugged into each receiver.
Powerline products send the audio by means of the power mains and offer great range. They run into problems in homes where there are individual mains circuits in terms of being able to cross over into another circuit. Powerline products have another problem in the form of power surges and spikes which can cause transmission errors. To prevent audio dropouts, these products will commonly have an audio latency of several seconds as a safeguard.
Now we’ll give you some recommendations for shopping for a wireless system: Pick a system that supports multiple wireless receivers if you plan to stream audio to several rooms so that you don’t have to buy a separate transmitter for each receiver. Products with some sort of error correction will be more resistant against radio interference from other wireless transmitters. Select a digital RF transmitter to maintain the original audio quality, ideally one with an audio latency of less than 10 ms in case of video or other time-sensitive applications.
Make sure the wireless transmitter offers the audio inputs you need. You may need amplified speaker inputs, RCA audio inputs etc. Get a wireless system where you can purchase additional receivers later on. You should check that you can get receivers for all the different applications you have. Such receivers may include amplified receivers for passive speakers or line-level receivers for active speakers. If you go with a digital audio transmitter, select one with an input audio level control knob to avoid the music signal from clipping inside the transmitter audio converter. This will ensure optimum dynamic range regardless of the signal level of your equipment.
For high amplifier power efficiency and best sound quality, verify that the amplified receiver has a built-in low-distortion digital amplifier. Pick a system which offers receivers that can drive speakers with the preferred Ohm rating. Make sure the receivers have a small form factor and are easily mountable. This will help during the set up. Products which work in the 5.8 GHz frequency band will have less trouble with wireless interference than products utilizing the crowded 900 MHz or 2.4 GHz frequency band.