If I can duplicate what an electronic crossover can do using a capacitor and resistor inserted between the pre-amp and power amp, will a passive filter be a better option vs an digital electronic crossover such as the Minidsp 2 x 4 ?
Actually, what a minidsp can do - It will be pretty complex to do with capacitors and resistors. These typically will be two different use cases.
If the requirement is a simple first order crossover at 50hz without any eq or delays, then an RC filter should work, Right ? If so, will an RC filter be a better option ?
Between a preamp and power amp a high first order high pass can be implemented in a passive circuit. It will not add noise, distortion or digital artefacts, and cost cents. If you know the input impedance of the amplifier, only need a capacitor of the right value.
https://www.electronics-tutorials.ws/filter/filter_3.html
https://www.electronics-tutorials.ws/filter/filter_3.html