cant hear you dude these lights are loud :smoking:ive got 3 running in the loft 2x 150 and 1x 250 se there not as loud as mars but I wouldn't like them in a room with me all night I would say about as loud as a lap top but ive got the older light I think @AMARE-TECH-Vic has updated the fans in the latest ones hope that helps

I think the pro series are a little quieter. I don't think a noise free light is possible but these aren't bad at all. The solar spec lights I have have 6 fans and they are comparable to my cheaper 2 fan lights. Top of the line all the way around. Even down to the shrouds around the fans.
you can do cobs with passive heat sinks not to sure on the dimension of the heat sink you would need all depends on how many cobs and what power not sure on spectrum king I think you can by the kits online complete with passive heat sinks noise is a bit of a problem for me but I cant hear anything from my lights but they are in the loft my air pump makes more noiseI kind of "beg to differ" … I perfectly understand that premium silent fans are not top priority for manufacturers, but for some end users it certainly is, like myself. On the other hand, extremely cheap, inefficient and noisy as hell fans are all too normal to find - hence my question.
That is exactly why I went ahead and bought SilenX fans for my GN Ms0006's - I am an apartment grower, and having noisless setup for cheap night-time electricity is a must. I did got through very thorough CFM analysis prior to it of course, cost me an arm, but 100% worth it and in terms of electrical savings it payed for itself within a few months.
It certainly is possible to have a whisper silent light. Though it will cost significantly. Aren't Spectrum King lights completely fanless even ?