Homemade DIY PASSIVE RADIATOR on JBL Charge 3 - YouTube
The Subwoofer DIY Page - Passive Radiator Systems
Passive Radiator Configuration - DIY Audio Projects - StereoNET International
Building a Small Passive Radiator Subwoofer- by SoundBlab - YouTube
Updated Foam 95mm Passive Radiator Speaker Bass Radiator Auxiliary Woofer For Altec 4 Inch 5 Inch Woofer Subwoofer Speaker Diy - Speaker Accessories - AliExpress
Make a 4.75 Inch Passive Radiator Speaker Dirt Cheap From Scratch (pair) : 10 Steps - Instructables
Making a Passive Radiator - YouTube
Cheap DIY Passive Radiators | DIYMobileAudio.com Car Stereo Forum
Passive radiator speaker cabinet with calibration box made by me, I optimized the frequency response of cheap passive radiator bought in aliexpres. Achieve 40 Hz - 16KHz with 3 dollar PR : r/DIY