We explore the ground state properties and excitation spectra of one-dimensional, three-component bosonic mixtures, where two majority components form a self-bound droplet coupled to a third, minority component. Within a self-consistent Lee-Huang-Yang framework, we identify distinct mixed self-bound droplet phases and characterize their phase transitions through variations of either the particle number of the majority components or the intercomponent coupling. The ensuing phases demonstrate that the minority component is untrapped, partially trapped, or fully trapped by the majority droplet species. These states are characterized by their binding energies captured by the chemical potentials and their low-amplitude excitation spectrum, including mode crossings at the particle-emission threshold. We further derive effective reduced models in the high-imbalance limit, which accurately reproduce the numerically computed ground states, while providing analytical insights into the role of quantum fluctuations. Our results establish the stability and structure of mixed droplet phases provide experimentally relevant signatures for their identification.