10-Inch Low-Profile Amplified Subwoofer System - 900 Watt Compact Enclosed Active Underseat Car Audio Subwoofer with Built In Amp, Powered Car Subwoofer w/ Low & High Level Inputs - Pyle PLBX10A - Walmart.com
Speaker-Level Inputs on Subwoofer and "protecting" smaller speakers | AVS Forum
8-Inch Low-Profile Amplified Subwoofer System - 600 Watt Compact Enclosed Active Underseat Car Audio Subwoofer with Built in Amp, Powered Car Subwoofer w/Low & High Level Inputs - Pyle PLBX8A : Amazon.ca:
How to add high level inputs to any Sub or Subwoofer outputs to any amplifier. - YouTube
What are the speaker outputs on my subwoofer for? - Quora