In a self-sensing actuator, a single piece of piezoelectric element is used simultaneously as a sensor and an actuator. Since the sensor and actuator are placed at the same location, they are truly collocated. Recently, a self-sensing active constrained layer (ACL) damping treatment has been introduced. This work has shown that a self-sensing ACL will eliminate system instability. However, while the viscoelastic layer of the ACL treatment will enhance damping, it will also reduce the control authority from the active source to the host structure. In this study, an enhanced self-sensing ACL treatment is proposed. The viscoelastic layer is still sandwiched between the host structure and the piezoelectric constraining layer. The single piezoelectric element is used as an actuator and a sensor simultaneously. By adding two edge elements onto the boundaries of the piezoelectric cover sheet, the actuator authority can be increased due to the direct transmissibility from the piezoelectric layer to the host structure. On the other hand, the sensing capability of the piezoelectric element can also be increased because the converse transmissibility from the host structure to the piezoelectric layer is enhanced. A beam structure with a partially covered enhanced self-sensing ACL is implemented to investigate the system characteristics. Both actuating and sensing abilities are evaluated. Their concurrent sensing/actuating performance is also investigated. Experimental results show that the two-way bypass effect via the edge elements can significantly improve the piezoelectric actuating/sensing abilities, and the overall performance. Therefore, this enhanced self-sensing ACL damping treatment can provide an effective means for structural vibration control.