Vibration energy harvesting has emerged as a promising approach to power small electronic devices and sensors, particularly in remote or inaccessible locations where traditional power sources are impractical. Among the various transducer mechanisms, electromagnetic vibration energy harvesters (EVEHs) have garnered significant attention due to their relatively simple design, high energy conversion efficiency, and scalability. However, the performance of EVEHs is heavily dependent on the structural configuration and relative positioning of the magnets and coils within the transducer. This study investigates the optimization of the EVEH structure to maximize the harvested voltages and power output by a comparatively study using three (3) design scenarios namely single coil-four magnets circuit, single coil-split magnet circuit and two coils-split magnet circuit within an equivalent coil magnet volume. A comprehensive parametric analysis is conducted to examine the effects of the magnet-coil gap, coil position, and magnetic flux density on the EVEH's performance. Analytical models are developed to predict the open-circuit voltage and power output on a prototype EVEH system. This work will provide valuable insights for the design and implementation of high-performance EVEHs, contributing to the advancement of self-powered and sustainable electronics. The results will demonstrate that by strategically positioning the magnets and coils, the bandwidth, harvested voltages and power can be significantly enhanced or compromised.