"Marnok.com"

I just bought some (fairly cheap) IR stereo headphones. They work ok, but
with a very audible hiss even at very low volume when there is no sound
from the source (PC). This could quickly get annoying. I wondered if anyone
could tell me, is it that I just have a poor quality product or is this
sort of noise somehow inherent in the technology?


** Seems you have bought these:

http://tiranossaurus.com/product.asp?id=055253

The specs reveal it uses twin carriers ( 2.3 and 2.8 MHz) and FM modulation
of the pulsed IR light.

The receiver ICs are generally the same as those in FM demodulators - so
will hiss loudly in the absence of signal.

The claimed 55dB s/n is probably optimistic or heavily weighted or both.

Similar IR phones from Sennheiser claim only 46 dB s/n.

Good enough for low dynamic range stuff like TV listening.



...... Phil