I think for the time being, I'm going to use a simple plastic connector on the outside of the box in order to be able to quickly disconnect the speaker wire and remove the box. I wanted something from
TURCK - Capacitive Proximity Sensors, Inductive Proximity Sensors, Connectors, Cables, Cordsets, which has commercial applications for wires and connectors. We use them extensively at work. Because of the grade and quality, they would be pricey for an application such as this. But I haven't found anything on their website yet that would be ideal and cost feasible.