Is it normal for there to be some hiss from speakers?

[turul]

It's like a constant air blowing noise. It comes from all my Sony Bravia 5.1 speakers. I can only hear it when I stand only a feet or two away, more than that and I can't hear it at all. It doesn't increase with an increase of the volume, and occurs even when all other components, including the TV, are off.

 

[JAYDEEJOHN]

Its a current leak, poor shielding. Somethings giving off frequencies your speakers are picking up, or other components in your audio structure.
No need to worry unless its a huge bother

 

[turul]

Well I went to Futureshop and found my speakers on two displays. I put an ear against them to test and heard the same hiss. I tried other speakers and couldn't hear it (I only tried a few though). Seems it's confined to this particular model.

It's this model for anyone interested:
http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0770HDS0010124780&catid=19701

I would return them, but it doesn't really bother me. I don't sit 1-2 feet away from them so I can't hear it at all.