Wireless Headphones. An explanation of how wireless headphones work and the technology behind them, as well as the different types available and where to buy them.

Headphones are an obvious candidate for the wireless revolution, since they are more or less attached to the user, who will often want to move around while using them. The problems inherent to wireless devices will of course apply to wireless headphones, including interference from other radio sources, signal noise due to surrounding electromagnetics and limited range. There are however a number of wireless headphone sets available and they vary in terms of sound quality, mainly dependant on the quality of the headphones themselves.

Wireless headphones are available in both IR and RF, and it's worth considering their intended use before making a choice at that level. Infra Red wireless devices can only be used in a small area quite close to the transmitter and in line of sight, but aren't susceptible to interference for that reason. Radio Frequency wireless can be used at much greater distances and through barriers, although some suffer from reduced sound quality as range increases. RF also suffers from interference from other devices using the same frequency band.

In truth most wireless headphones are RF, with frequencies ranging from 700Mhz to almost 6000Mhz, so shopping around for a headset which uses a different frequency to any nearby radio sources may be advisable. Wireless Headphones seem well suited to wireless applications and there are many good products available from the following sources.

Sennheiser - Wireless head-phones. www.sennheiserusa.com

Amazon.com - Wireless head-phones. www.amazon.com

HeadRoom - Wireless headphones. www.headphone.com

Wireless RS130

• Transducer Principle Dynamic, opened
  
• Frequency Response 18-21000Hz
  
• Weight Of Cable approx. 275g
  
• Characteristic Spl at 1 kHz 104 dB
  
• Ear Coupling Circumaural
  
• Distortion < 0.5%
  
• Power Supply 2.4 V - 3 V via 2 AAA size NiMH batteries (LR 03)
  
• Operating Time on Wireless headphones batteries approx. 22 h
  

Wireless SET810

• Operating Time >4 hours (Receiver)
• Frequency Response 40 Hz-15,000 Hz
• Max Spl >125 dB(SPL)
• Dimensions 5" D x 1 3/4"H(Transmitter) 9"H x 4"W x 1"D(Receiver)
• Weight 3oz(Transmitter) 2.3oz(Receiver)
• Signal To Noise Ratio on Wireless Headphones 60 dB(A) eff