This thesis presents the mechanical validation and correlation of a Back-to-Back eBench. The objective is to enhance the accuracy and reliability of mechanical performance assessments and update the extended Digital Twin (xDT) of the system. Firstly, a general overview of the NVH field is provided, highlighting its purposes, challenges and current industrial problems. The theoretical background needs to understand these topics is then outlined, focusing on the electric motors, the Experimental Modal analysis and the application of Impact and Shaker testing for real eigenvalue analysis and its corresponding mode shapes. The use of both testing method is crucial to verify results and compare analysis.