When I accelerated hard from 60kph to 120kph I can heard off-pitch "vroom", like crackling sound. RPM is like 4-5K when I hear the sound. If my ICE is on, the sound will be from the speakers, if I off the HU, sound like comes from the front. The strange sound was very loud with my stock car battery, but with my recent battery change, the sound was not that loud. It's not aeroplane sound.
Can expert offer solutions to elmimate the sound?