I had active Tannoy Reveal monitors from 2005 and they had a very light his when on and not playing music, but you need to keep your ear next to the tweeter to hear it. From half a meter distance you hear nothing (even I, with very sensitive ears).
My actual passive desk speakers are self designed bookshelfs with a Mark Audio Alpair 10.3M fullrange drivers and some passive eq applied to it, and they have no hiss at all with my marantz PM5004 amplifier, but they do have his when i use the Hypex UcD amps i also have (but not use anymore). I did build Ncore 400 amp kits for someone and those did not have them altough when i tested them.
In my listening room i'm sitting about 3m from my speakers, so i don't hear nothing at all. But all are passive diy speakers with class A or tube amps. When i go close, the tube amp has some noise, but no a his, more a low tone and very low (only when fully open on high efficient speakers). In my kitchen i use a very cheap class D amp powering old philips speakers that has massive amounts of his when not playing, but i switch it of when i'm not playing. That philips is a 2 way with a passive crossover, but it's not enough to remove the hiss. The hiss dissapears when there is input signal (even when it's low) luckely...
I think it's mainly amp depending, and often class D (and mainly the cheaper and/or older ones) amps give hiss, (but not all of them). I'm not technically schooled enough to know why, but that is my personal experience.