Hissing from speakers?

[mobily]

Hello all,

I am writing on behalf of my dad who has discovered an irritating problem with his dav 500 system. Whenever the system is switched on there is a hiss coming from all the speakers. At most volumes this isn't noticeable, however when listening to a cd in 2 channel for example you can hear the hiss out of the centre speaker and the rears. Is there any way of eradicating this? Also is this problem also present on it's descendant the 550?

Out of interest I put a cd in and accessed the pro logic mode. The sound only seemed to come out of the centre speaker with some feeble sound from the rears. Is pro logic more like 3.1 than 4.0?

Thanks for all your help,

James

 

[KraGorn]

I don't know this equipment so can only speculate.

Hiss can either be a 'feature' of the equipment, eg. my Logitech Z680 PC surround system makes a very low-level hiss which is simply a result of its' design, why it does it I don't know but it's un-cureable.

This sort of noise isn't affected by the settings of volume or tone controls, it comes from somewhere in the power-amp output stages often the power transistors themselves. Tacking down the cause isn't easy, remedying is even harder.

As for your Pro Logic question, there are two modes to PLII, 'cinema' and 'music', 'music' mode emphasises the fronts over the rears while 'cinema' produces more of an all-round sound image .. your description makes it sound like you selected 'music'.