Shoutout to Sam from Barevids and the other people who already made videos about these that I watched and decided to make one for myself. I'm guessing a lot of people missed those great videos so I made a crappy one. All you need is a spare speaker and one cheap capacitor that you can get from Amazon or wherever. Here is my affiliate link for it. https://amzn.to/4fCQ6hy - (edit) Had to change the link because they were out of the right ones. You want a 400v, 2.2 to 3.3 uF, non polarized capacitor. These will work, but it's a 10 pack for $12. They are +/-3% also so that's good. Wire that guy in series on one of the wires leading to the spare speaker and you are good to go. This won't affect the impedance of the speaker/s. The cap filters everything out unless it is above 30k hz or something like that. So you shouldn't hear anything unless weird frequencies are being created by distortion, and that is all you will hear. With a very sensitive speaker it seems like you can hear down to around 1% thd, around 5% for sure. So this is actually better than a clip light. I hope this is helpful. Capacitor to make a DD-0.01 (10 pack) - https://amzn.to/4fCQ6hy Taramps Smart Charger 200/280A Battery Charger - https://amzn.to/3W3m0Ns