[JBL Tools app]

Must-have app!

[Italian version here]

Product name: JBLTools app/software
Manufacturer: Harman of Brasil - Brasil
Cost: free download for Android
Reviewer: Lucio Cadeddu - TNT Italy
Reviewed: October, 2021

We all use our smartphones for music listening, via YouTube or the various streaming platforms, but there's more we can do. There's an endless list of - mostly free - apps that we can install for audio/HiFi purposes. Among these, my favourite one is JBLTools, designed by Harman of Brasil, that's the Brazilian Company, which is part of the Harman Group.

This app is 100% free and available on Play Store for Android devices (I've not found it on the Apple Store). JBLTools is mainly a repository for many different tools, it is extremely well made and easy to use, with instructions (in English) and an extremely user-friendly interface. The app offers six different sections (with subsections), we're going to explore in the following: Speaker - Calculations - Polarity Checker - SPL Meter - RTA - Wavelength.


This section contains fill-in forms that allow you to calculate the volume of a given box of different shapes: rectangular, cylindrical, prism-shaped vertical, prism-shaped horizontal. Just fill in the blanks and let the app do the maths for you. You can even insert wood thickness and box volume with/without speaker. Just click on calculate and you're done.

[JBL Tools app][JBL Tools app]


This section contains six different subsections:

Polarity checker

This section lets you discover whether your loudspeaker (or your system) respects the correct polarity. This requires an MP3 file that appears to be no longer available on the app website. In any case, you can use any MP3 polarity checker file that can be easily found on the web. The section contains the instructions on how to perform this measurement.

SPL Meter

This section contains a fairly accurate SPL meter, i.e. a tool that measures, with the hep of the mic of your smartphone/tablet, the sound pressure level while you're listening to your system (I do not know if it measures dB or dBA, it is not specified). It is not 100% precise as its precision depends highly on the quality of the microphone, but it still gives a gross estimate. This information is of paramount importance if you wish to avoid spending some extra cash on power you don't really need. The app gives readings of peaks and real time measurement in terms of dB. In a standard living room, it is hard to exceed 90/95 dB peaks. Above this level your neighbourhoods will be calling the police (or knocking at your door/ceiling/walls/floor). It's useful for those who think they need 1000 watts per channel, when they really use 15/20 watts. Do not let your wife/spouse understand how the SPL meter works ;-)

RTA (Real Time Analyzer)

This section shows the frequencies generated by your system, by means of a choreographic dance of blue bars. This is the so called Real Time Analysis or spectrum analysis.


This sections does more or less the same as the above, except that it displays the sound in terms of waveform, instead of dividing it into different sections/bars.

[JBL Tools app]


For the die-hard DIYer or for the audiophile who wants to better understand certain aspects related to his system, this is the app to have. It is free, it works well and it is extremely easy to use. Things are explained in layman's terms and you do not need a degree in physics to understand how things work. Sometimes, at least on my OnePlus phone, the app crashes, but it can be reopened in a fraction of a second. Too bad it isn't available for iOS.

DISCLAIMER. TNT-Audio is a 100% independent magazine that neither accepts advertising from companies nor requires readers to register or pay for subscriptions. After publication of reviews, the authors do not retain samples other than on long-term loan for further evaluation or comparison with later-received gear. Hence, all contents are written free of any “editorial” or “advertising” influence, and all reviews in this publication, positive or negative, reflect the independent opinions of their respective authors. TNT-Audio will publish all manufacturer responses, subject to the reviewer”s right to reply in turn.

Facebook logo

© Copyright 2021 Lucio Cadeddu - editor@tnt-audio.com - www.tnt-audio.com