2 PCS Car Line Audio Output Converter, 2.26" x 1.5" x 1" High Resistance to Low Resistance Plug and Play Speaker to Line Level Converter, Portable Accessory, for Most Cars (Multicolored)

OK, we all know that we shouldnt drive a line input from a speaker output, but sometimes it's our only reasonable option. These seem well designed, with proper pads and isolation transformers, so they should work with just about any configuration. You could spend a LOT more for units that may look better but won't work better.

This adapter is what I used to get sound from a Bluetooth amp having standard speaker connectors into some active speakers. The adapter steps down the current and gives you rca connectors. Easy to connect and works perfectly.

Great impedance converter that doesn’t have static any longer.