Review on 🔊 uxcell Automotive Speaker Audio DIY Phase Tester PH Phasemeter - Black by William Obong

Some time ago I installed my own radio. Picked this up on a whim to check polarity on a car speaker. It takes a 9V battery which is not included and in the 21st century I don't have any (so I stole one from the multimeter). Quite easy. I copied the CD that came with it (all in Chinese but it's obvious which track is the polarity test because it's a series of pops). Turn on the MP3 player on my car stereo, turn down the volume (so other speakers don't interfere), hold the meter to the speaker, press the button and watch (Green, Green, Green, Red is good --- - Red , Red, Red, Green is bad ). Turns out my tweeters were wrong all along. Swapped cables and the car sounds better than ever. I'm very glad I bought this.