Need your help. I have the onkyo HT780 HTIB. Sometimes when it is turned on and seems to be only the weekends the frt/L speaker will sound like wind is blowing thru it. Turning the reciever on and off worked last week but today it did not. It did stop eventually. However there is a slight hiss coming out of the Frt L/R Center tweeters all the time the surrounds are all ok. Not sure whats going on here i would expect no interference on shielded speakers and why only the frt L.
Shielded speakers refer to the shielding done to the speakers' magnets which allow placement close to a cathode ray picture tube. (CRT = a conventional "picture tube" type TV.) It has nothing to do with shielding from RF interference. Speaker cables should not require shielding as they are consider above the level of signal to noise required for such protection. Additionally, shielding protects against RF interference which is a radio frequency breaking through the signal, not a constant noise.
A "slight hiss" is generally considered normal as this represents the typical circuit noise of most amplifiers. How much noise you hear is dependent on several factors in the system. If all speakers are exactly identical and you are hearing more noise from one speaker only, that is probably an indication of problems in the amplifier/receiver. With a HTIB, this is not that uncommon since the circuits in these components are meeting a price point and then a quality point.
If you are hearing a sound that replicates wind blowing, there is a good reason to suspect the processor in the HTIB. Whether this is acceptable under the manufacturer's specifications of performance is something that can be answered by direct comparison to a similar unit at the dealership. If the dealer has a similar unit on display, ask for a demonstration. Otherwise, return the unit and ask for the shop to hook up your unit and pass judgement.
I'm sorry to say, most HTIB's are not of great quality and problems such as this are sometimes to be expected if the noise is not audible over music. If the problem has developed over a period of time, i.e. the unit is not under warranty, there is probably a problem in the processor and the unit will need repair by a technician.