Hi, bought a Marshal stanmore bluetooth speaker about half a year ago and just recently noticed that it makes a very low hiss sound like smooth air blowing or something, the sound is there no matter if the sound is turned up or all the way down. I did some light googling but all i could find was videos of ground loop issues which this doesn't sound like. The sound is not a humming sound like from guitar amps, just a low hiss/static noise. It might have been there from the beginning but now that i noticed it ive become really observant of it. I love the speaker in general so its not a big problem if its a normal expected thing from this kind of speaker. But im quite the noob at audio stuff so im afraid that it might have been blown or something else is wrong. Any insight would be greatly apriciated.