Speaker-level inputs or line output converter (LOC)?
Thomson Computer Speakers, 2.0 Stereo USB Powered Desktop Speakers HiFi Sound Quality with 3.5mm Aux Input Output, Bluetooth 5.0, Volume Knob, PC Speakers for Desktop, Laptop, Cellphone, Monitor - Newegg.com
Amazon.com: Dingsun 3.5mm Audio Switcher 4 Port Audio Selector Box Support Connection of Active Speakers, Headphone, MP3/MP4, Android Phone, Game Console, PC, etc. (1 Input 4 Output/ 4 Input 1 Output) : Electronics
A1 Home Music System — Audioengine
How to connect two audio devices to one output - Quora