Micro Cooling Fan must be installed securely in order to reduce noise?

Imagine if "Micro Cooling Fan" no very firmly fixed on the heat sink, but a very loose, so that the high-speed rotation of the fan in the process will produce what kind of phenomenon? Many people will certainly blurted, fans certainly will produce a very strong noise, in fact, this argument is very one-sided. Although a number of fans on the market are the cooling fan is firmly secured to the heat sink, but there are "Micro Cooling Fan" and the fan does not directly fixed to the heat sink, but is fixed in a plastic frame. We are aware of the source of noise of the fan is caused by resonance, in order to reduce the noise caused by this reason, many of the fan through a flexible plastic frame having a fixed, in order to play a role in preventing the resonance. When such a fan is directly after the frame is fixed to a plastic, and then fixed to the plastic frame by snap-on fins, the soft reduction "Micro Cooling Fan" four corners, will find room for a fan with a certain space for the movement, and to do so not fixed too strong, but in order to reduce fan noise during the operation to take special design. So, the idea that the fan must be installed in order to reduce the noise to say firmly biased!