Maybe. But why make it harder than it has to be? The elegant solution is what I did, a simple 2 resistor mod to the amp. https://systems.audiogon.com/systems/8367 See picture #26.
Or if you don't want to change your amp then you can use the same two resistor circuit connected between speaker outs and sub in. https://www.epanorama.net/circuits/speaker_to_line.html
Or if you don't like that then just buy one of these https://www.parts-express.com/car-audio/car-audio-installation-accessories/line-output-converters-co...
Or if you don't want to change your amp then you can use the same two resistor circuit connected between speaker outs and sub in. https://www.epanorama.net/circuits/speaker_to_line.html
Or if you don't like that then just buy one of these https://www.parts-express.com/car-audio/car-audio-installation-accessories/line-output-converters-co...