Solder Vs Crimp

[grimsubaru]

That point is valid and needs repeating. If you want high end audio, perhaps your going to need to run some new wires through your door hinge, cause somewhere under the dash is going through a connector. In fact, one should run speaker wire specifically, cause it has capacitance / inductance values that are tuned to its per meter resistance so that frequencies of 10Hz to 20kHz are transmitted optimally flat (frequency response). Since the wires aren’t paired together in the wiring harness, extra effort to make a soldered connection is likely fruitless in terms of maintaining frequency response.