Recently more and more wireless audio transmitter devices have emerged which claim to deliver the ultimate freedom of sending music throughout the house. We will research if these latest products are suitable for whole-house audio. Also, we will give important tips for selecting a wireless music system.
Running music in your house can be a daunting job. A lot of buildings are not wired for multi-room audio and getting the music from your living room to your bedroom can be quite a problem. Devices which resolve this difficulty are usually based on the following technologies: infrared wireless, RF wireless, wireless LAN or powerline.
Infrared is limited to line of sight because the audio signal is broadcast as lightwaves and consequently products using this technology, such as infrared wireless surround sound products, are restricted to a single room.
RF wireless audio devices send the audio signal via radio waves. These radio wave signals can easily go through walls. The signal is sent either by using FM transmission or digital transmission. FM transmitters are the least expensive alternative. They provide decent range but the audio signal is prone to audio distortion and noise and is extremely susceptible to interference from other wireless transmitters.
Digital wireless audio transmitter products, such as products from Amphony, utilize a digital protocol. The audio is first converted to digital data before being broadcast. This conversion and transmission in the digital domain will guarantee that the original audio quality is preserved. On the other hand, this is only the case of the data is sent uncompressed. Some wireless audio transmitters will apply some type of audio compression. Such products include Bluetooth audio transmitters. Audio compression will degrade the quality of the audio to some extent.
Products using wireless LAN are practical when streaming audio from a PC. Their drawback is that they generally have some fairly high latency, i.e. the signal will be delayed by some amount since wireless LAN was not particularly 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 music. These products normally offer excellent range. On the other hand, they face trouble if there are a number of separate mains circuits in the home. In this case the signal will have trouble crossing between these circuits. Powerline products have another challenge in the form of power surges and spikes which can cause transmission errors. To prevent audio dropouts, these products will generally have an audio latency of several seconds as a safeguard.
Here are some guidelines for selecting a wireless audio system: If you plan to stream audio into several rooms of your house, be certain to go for a system that allows streaming to several receivers at the same time. That way you don’t have to purchase a separate transmitter for each receiver that you are streaming to. Some products have some type of error correction built in which will help guard against dropouts in case of strong wireless interference. Choose a digital RF audio transmitter to ensure that the audio quality is preserved. Make sure the audio delay is less than 10 ms if you have a real-time application such as video.
Make sure the wireless transmitter offers the audio inputs you need. You may need amplified speaker inputs, RCA audio inputs etc. Make sure that you can buy additional receivers later on as you expand your system. Check that you can get receivers with speaker outputs for connecting regular loudspeakers as well as receivers with line-level RCA outputs. If you go with a digital audio transmitter, choose one with an input audio level control knob to prevent the music signal from clipping inside the transmitter audio converter. This will ensure optimum dynamic range regardless of the signal level of your equipment.
Ensure that the system provides amplified receivers with a digital amplifier to ensure high power efficiency. This will help keep the receiver cool during operation. In addition, make sure the amplifier provides low audio distortion. This is vital for good sound quality. Verify that the amplified receiver is able to drive speakers with the desired Ohm rating and that it is small and easily mountable for easy set up. 5.8 GHz wireless devices typically have less trouble with interference from other wireless transmitters than devices working at 900 MHz or 2.4 GHz.
Author Resource:
Brian Fuller has been involved with designing wireless and other electronic devices for over 10 years. You can get additional details about wireless audio transmitter products at Amphony's website.