The newest range of wireless audio transmitter devices promises streaming of music throughout the house without limits. We will take a look at various products and technologies to find out in how far these devices are practical for whole-house audio uses and what to look out for when purchasing a wireless system.
Running music in your house can be a intimidating job. Numerous houses are not wired for multi-room audio and getting the music from your living room to your bed room can be quite a problem. There are several technologies solving this problem. These include infrared wireless, RF wireless, wireless LAN (WLAN) and powerline.
Infrared products broadcast the audio as lightwaves. Light cannot go through walls. Consequently devices using infrared, such as wireless surround sound kits, are limited to a single room.
RF wireless products send the music as RF waves – either by utilizing FM transmission or digital transmission – and can therefore without difficulty transmit through walls. FM transmission is inexpensive but quite prone to static, audio distortion and susceptible to interference.
Products utilizing digital wireless audio transmission, such as Amphony audio transmitter products, make use of a digital protocol in which the audio is converted to a digital signal prior to transmission. This method guarantees that the audio quality is fully preserved. Some transmitters utilize some type of audio compression, such as Bluetooth transmitters, which will degrade the audio to some extent. Transmitters which send the audio data uncompressed will attain the maximum fidelity.
WLAN products are convenient for broadcasting audio from a PC. However, wireless LAN was never designed for real-time audio streaming. As a consequence, products using WLAN will introduce some amount of delay to the signal. WLAN receivers often do not have built-in network access. As a result, such products often require buying separate LAN cards. These cards are then plugged into every receiver.
Powerline devices use the power mains to distribute music and provide large range but run into trouble if there are separate mains circuits in the house in terms of crossing between circuits. Another problem confronting powerline products are strong power surges and spikes. Such surges can bring about drpouts in the audio due to errors in the transmission. To safeguard against these errors, powerline products generally build a delay of several seconds into the transmission.
Here are some suggestions for choosing a wireless audio system: If you plan to stream audio into several rooms of your house, be sure to pick a system that permits streaming to multiple receivers at the same time. That way you don’t have to purchase a separate transmitter for every receiver that you are streaming to. Products with some form of error correction will be more immune against radio interference from other wireless transmitters. Digital RF audio transmitters will be able to maintain the original audio quality. If you have time-critical applications where sync of the audio is important then you should get a transmitter with a low audio latency. An audio latency of smaller than 10 ms would be suitable for most scenarios.
Pick a transmitter that has all of the audio inputs you need, e.g. speaker inputs, RCA inputs etc. Choose a system where you can add receivers later on which offer all of the required outputs, e.g. amplified speaker outputs, RCA outputs etc. If you go with a digital audio transmitter, select one with an input audio level control knob to prevent the audio signal from clipping inside the transmitter audio converter. This will ensure optimum dynamic range regardless of the signal level of your equipment.
Check that the amplified wireless receivers contain built-in digital amplifiers with low distortion figures. This will keep the receiver cool due to high amplifier power efficiency and offer maximum sound quality. Select a system that provides 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. 5.8 GHz wireless devices typically have less problems with interference from other wireless transmitters than products operating at 900 MHz or 2.4 GHz.
