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Mobile Solutions' All New PT-9A+ Polarity Tester

A Critically Important Audio Test Tool Ever Technician Needs

TEMPE, Ariz., August 4, 2020 — Mobile Solutions announces the release of a new and exciting audio system test tool: the PT-9A+ Polarity Tester. It’s is an essential measurement tool for building and tuning great car audio systems. Advancing on the previous and highly successful PT-9A model, the new PT-9A+ adds even more capabilities to analyze signals, particularly in OEM audio system integration.

“In any car audio system, it’s critical to identify and verify the correct polarity of speakers, both before and after installation. The polarity of the electrical signals that connect to the speakers in OEM audio integration, as well as correctly identifying which wires correspond to which speaker locations, is also critical to verify” comments Bryan Schmitt, President of Mobile Solutions. The PT-9A+ does all of those tasks in one compact, easy-to-use tool.

The PT-9A+ has a safe, low voltage output pulse on either the preamp level (RCA) plug or speaker jacks. It generates polarity pulses directly into a speaker or AUX input, or the technician can use pulse tracks from the included USB thumb drive and load them on a portable media device. The built-in microphone on the front of the tool then determines if the speaker cone moves outward with the pulse (correct polarity) or inward (reversed polarity). The low voltage of the pulse means no damage to CAN Bus wires, Air Bag wires or other sensitive circuits if the technician mistakes other vehicle wiring for audio signal or speaker wiring. In the past, technicians would sometimes try to ‘pop’ speakers with power tool batteries or tape wires to a 9V or D cell battery for this task. The PT-9A+ is a much safer and professional way to pulse speakers and determine absolute acoustic polarity.

The game-changing new feature of the PT-9A+ is that the speaker jacks not only function as outputs for generating output pulses, but the jacks can be configured to accept speaker-level INPUT up to 4VAC to identify the electrical polarity of an audio signal. This feature essentially tells the technician which wire is positive (+) and negative (-) so that, when doing an OEM audio integration job, the inputs to a DSP or amplifier can be configured correctly with respect to polarity. Cancellation between audio signals (acoustic or electrical) is the number one problem that plagues most car audio systems which exhibit poor sound performance. “When all of the audio system’s signals and speakers are correct in polarity, only then can the technician do effective tuning for optimum sound quality” adds Schmitt.

polarity 1

PT9A+ Features:

  • Built-In Selectable Pulse Generator - Preamp Level (RCA) and Speaker Level Jacks
  • Built-In Compact Microphone for Testing/Verifying Acoustic Speaker Polarity
  • Speaker Level Jacks can be configured as Inputs for Electrical Signal Polarity Testing
  • Low Volume Threshold for Safe Testing – System volume does need not be loud to test
  • Easy-to-Understand Polarity LEDs – Green = Correct, Red = Incorrect
  • Built-In Low Battery Indicator LED
  • Includes USB Thumb Drive with Polarity Pulses and Pink Noise
  • Comes with a Protective Storage Case, Quick Start Guide and Insulated Test Leads
  • Uses a Standard 9V Battery (Not Included)

PT9A+ Applications:

  • Test polarity of audio system speakers before starting an installation or tuning
  • Generate pulses into the audio system to verify speaker location and polarity
  • Test polarity of OEM audio signals at the source unit or amplifier output (up to 4V)
  • Identify speaker location and polarity in OEM audio systems using internal pulse generator
  • Verify polarity shift in active or passive crossovers (especially 12dB/octave applications)
  • Optimize subwoofer polarity to blend with other system speakers for “up front” bass

The PT-9A+ is in stock at Mobile Solutions and shipping now. Special launch pricing of $99.99 is offered for a limited time by using the coupon code “PT9A-2020” upon checkout at

For more information about the PT-9A+ Polarity Tester or to place orders on any Mobile Solutions products, visit, or call 480-968-2074.

Mobile Solutions USA is an innovation-driven company creating tools and delivering training that enable custom automotive electronics, audio and interior installations progress with a level of efficiency not otherwise efficiently achieved in the aftermarket automotive business. With the patented Smart Templates™ brand of design tools and many other process-driven innovations, Mobile Solutions USA serves the aftermarket automotive technician, fabricator and retail store community through direct sales and distributors around the globe.

For more information, please visit

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