Amphony 1000 - Manual (Page 2)

Q: What is Forward Error Correction and why is it used in these headphones ?
A: Occasionally, there may be some data which is corrupted during transmission. This may be the
case when there is interference, such as other transmitters, electrical sparks or if you move around
and the signal is temporarily lost. Forward Error Correction as it is used in our headphones can in
most cases repair the data which is received to guarantee 100% correct data reception and
therefore 100% correct audio reception.
This technology is in part responsible for the high robustness of the transmission. With 900 Mhz
analog headphones you may have noticed ‘clicks’ or ‘pops’ during sparks which often occur when
switching on appliances.
Q: What exactly is a RangeBooster transmitter ?
A: A RangeBooster transmitter is a secondary transmitter which can be used to extend the opera-
ting range of the 2.4 GHz Digital wireless headphones. This is useful if you want to listen to your
headphones in areas where the signal may be blocked by walls or other obstacles. Also, the use of
RangeBooster transmitters is recommended in areas where there may be strong interference from
other transmitters, microwave ovens etc.
The RangeBooster transmitter can be placed in an area where signal reception from the main
transmitter is not possible or difficult. It is possible to use multiple RangeBooster transmitters. It is
necessary though to have a cable connection, preferably a coaxial cable connection, between the
location of the main transmitter and any RangeBooster transmitter. The audio will be transmitted
from the main transmitter to any RangeBooster transmitter via cable digitally, i.e. without any audio
degradation.
Please do not use a 5.8 GHz RangeBooster since it will
not work with your 2.4 GHz headphones.
Please do not use a 5.8 GHz RangeBooster since it will not work with your 2.4 GHz
headphones.
Q: What are the benefits of transmitting the full data rate without using audio compression ?
A: Since our transmitter transmits a data rate of over 3 Mbps (3 million bits per second), the audio
can be transmitted without audio compression. Also, forward error correction can be used. The
reason that other systems use audio compression is to reduce the extremely high data rate of a
pure (uncompressed) audio signal in order to either be able to store that signal or transmit that
signal more easily.
The biggest drawback of using audio compression is that the quality of the audio signal is reduced,
such as in MP3-compressed audio. This is because audio compression removes parts of the music.
Some types of music which are particularly difficult to compress without noticing audio degradation.
Systems using audio compression are not able to deliver CD-quality audio.
Forward error correction adds additional data to the transmitted signal so that in cases where the
data may be corrupted during transmission, the original data can be recovered at the receiver. This
ensures a very robust transmission.
© 2004 Amphony 2