The demand for low density, high strength, high conductivity Al-based alloys is continuously increasing, especially in overhead transmission power lines. Developing Al-based conductor alloys, however, has always been challenging; this is because the electrical conductivity and mechanical strength are mutually exclusive, indicating that the parameters leading to strength improvement deteriorate conductivity and vice versa. Therefore, in the present work, the properties of the Al-Mg-Si conductors were studied by adding alloying elements (e.g., Ag and Cu) and modifying thermomechanical treatment. In the conventional thermomechanical treatment, the impact of the alloying elements on the strength of Al-Mg-Si conductors was, to some extent, counteracted. The results indicated that the conventional thermomechanical treatment led to a less positive impact of the alloying elements on the strengthening. However, modifying the thermomechanical treatment resulted in maximizing the efficiency of the alloying elements on the strengthening. The strengthening precipitates of the alloys under different thermomechanical treatments were characterized and quantified using the transmission electron microscopy. In the newly developed alloys, higher number densities of the precipitates were acquired by applying the modified thermomechanical treatment relative to the conventional thermomechanical treatment.