KZ Castor Dynamic Drivers Earphones (Improved Bass Version)Experience unprecedented and breathtaking super bass When we set the bass frequency range to 20 200Hz, traditional manufacturers often attempt to adjust the sensitivity of this range by altering the unit's damping. The primary limitation here is that it's nearly impossible to boost only the 20 200Hz range without affecting the 300Hz range; excessive boosting in the 300Hz range leads to muddiness in the sound. However, with our KZ Castor's dual driver