Many papers have been ever presented for brake squeal, moan noise, creep groan noise and so on. Today it is required in brake design to consider the influences of countermeasure for every brake noise, because the moan noise countermeasure will cause sometimes low-frequency disk brake squeal for example. The countermeasure should be derived from the analysis for reducing both brake noises, but there is almost no paper of the relationship research between each brake noise. This paper describes the importance of every brake noise relationship, for example, the relationship between low-frequency disk brake squeal and moan noise.