Speed doesn't affect it, 0-100 there's no noise. Its about 3-4 inches from the top of the windshield, and the windshield on it isn't very steep at all, so there's a lot of wind going past it. Its pointed straight forward, and what's also interesting is that its not a very high quality lightbar honestly, it had a glass lens that cracked and shattered not plexi or poly or whatever they use, it has really good output but not high quality.
I replaced the lens with 1/4 plexiglass still didn't make any noise. It could possibly be the mounting brackets that make noise?? But I just used the ones that came with the lightbar, that weren't anything fancy at all lol