Mobile Solutions PT9+

(polarity tester)

TL;DR

Just buy it already

What is it?

A speaker test tone generator, acoustic polarity and electrical polarity tester

What does it cost?

List price is $124.99 USD

The Pluses

RCA out, speaker level in and out, simple and easy

The Minuses

9V battery not included? No more test CD, download it to USB?

This is the single most valuable tool there is for figuring out polarity out of the OEM amplifier. It’s also the single most valuable tool for finding where you got (+) and (-) backwards. And you do. Trust me, you do. Every speaker and passive crossover is at best a 50-50 shot. This needs to be part of your QC procedure. What’s that? You don’t? Well, you need one, and this needs to be part of it.

Many techs never get beyond “toning speakers out”. They should.

You will want backshell probes and perhaps alligator clips as well, but that’s true for every device with voltmeter-style probes like this one has.