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Hands on: Calibrate your TV to perfection with a clever new iPhone app from THX

Making the right adjustments to even basic picture settings on a TV is critical for getting good performance. The trouble is, the process requires tools and a little bit of understanding, and apparently that’s enough to put most folks off the idea entirely. As a result, a good portion of new TV owners end up settling for such horrible picture presets as “vivid” or “sports” – a decision that guarantees they aren’t getting the level of performance they paid good money for.

So, when THX told us it was working on an app for mobile devices that would allow users to calibrate their TVs and audio systems, we began holding our breath in anticipation. We loved THX’s idea of calibrating a TV using a smart phone or tablet, but in order to pull it off, THX was going to need to nail a handful of key design points: The app needed to be comprehensive, extremely intuitive, and inexpensive, if not entirely free.

We’ve given THX’s Tune-Up app a thorough test drive, and are happy to report that THX managed to nail all of those key points, and then some. The app is as comprehensive as it could be for this level of TV adjustment, anyone smart enough to navigate a smartphone can use it, and, for a limited time, it is free to download. THX even throws in some fun bonuses.

Presently, the app is only available for iOS devices. THX says it is working on an Android version, but certain inconsistencies among Android devices must be addressed before the app can be released. With that said, if you own an iPhone or iPad and a TV, we think you should get this app right now. Here’s what you can expect when you sit down to adjust your TV with THX tune-up.

How it works

Essentially, the app involves a series of modules which contain pictures and test patterns accompanied by voice instruction. You display these images on your TV or projector, and make adjustments to basic picture settings along the way. How do you get those images on your TV or projector? Ahhh…there’s the rub, friends: You need a Digital A/V adapter cable from Apple that converts your iDevice’s 30-pin or Lightning plug into an HDMI output. The adapter costs $39 at the Apple store, so even though the app is free (for now, anyway; it goes up to $2 after the promotion ends), you’re going to have to spend some dough – unless you just happen to own the adapter already.

You’ll then need an HDMI cable. While you could certainly borrow one from somewhere in your system, you might want to have a longer cable handy so that you can sit as far away from the TV as you normally do while performing adjustments.

Getting started

One of the beautiful things about the Tune-Up app is that it explains what to expect from it right out of the gate. After loading the app, you will be prompted to tap a “Get Started” button. Doing so queues up a two-minute video which, after a few self-promotional remarks from THX, explains in plain language with accompanying illustrations exactly what you’ll be doing.


Tapping the ‘equipment’ tab at the bottom of the screen allows you to tell the the app about the equipment you own. For the display adjustment, you can tell it you have a Samsung LED TV, or a ViewSonic Projector – you can even specify if the display is THX certified. These selections do not, however, seem to have any impact on the output of the test pictures or patterns.

For audio, the selection is a little more meaningful. It needs to know if it is dealing with a set of stereo or speakers or a 5.1 speaker system. Note that the app will not allow the selection of the 5.1 speaker system option unless the iDevice is connected via HDMI.

Picture adjustments

This is the real meat and potatoes section of the THX tune-up app, where the chance to launch the picture adjustment or sound adjustment options is made available.

Selecting picture adjustments displays a screen with all available options laid out
for quick access. You can start with any adjustment you like, but know that the app will continue from your start point in the order listed on this screen. You can always circle back or start over if you like. 

We started at the top with Apect Ratio and worked from there. THX first shows you a test image and gives verbal instructions on what to look for and how to adjust it on your TV. The voice-over can be muted, paused or started over as desired. Even though we have a good amount of experience adjusting televisions, we still found the guide helpful.

For instance, on the brightness test, we were told which numbered box on the test pattern and what part of the THX logo should appear to be barely visible. Switching over to the photo, the app explains that there is a pattern in the dark background that will only be visible with the proper brightness setting. Being able to bounce back and forth between the two helped us feel confident that the right setting had been reached.

Perhaps this app’s most clever feature is how it handles color and tint. Most consumer-level calibration DVDs and Blu-ray discs come with a set of tinted glasses which are used with special test patterns to adjust for color and tint levels. But THX makes use of the iPhone and iPad’s built-in camera instead. When the camera icon is selected during either test, the camera is activated with a red filter laid over the image. Black bars on the display’s image help make sure camera positioning is optimal. From there, all we had to do was adjust our color and tint sliders until the box-within-a-box disappeared.

Sound adjustments

The section of the app is significantly less comprehensive than its picture-related counterpart. It offers two tests: speaker assignment and speaker phase.

Speaker assignment simply runs an audio signal to each of the speakers set up in your system. If you hear a voice saying “left front” coming
from your right surround speaker, you know you have a problem to fix. Speaker phase helps to make sure that the positive and negative leads of your speaker wire are in the right place throughout your system. If they aren’t, you’ll hear it and be able to hone in on which speaker is attached to the improperly connected cable.

These are both important tests, since hooking speakers up out of phase or to the wrong output are both common issues. But we’d really hoped to see a speaker level test that employed a test tone and a decibel meter for balancing speaker output levels. Something tells us THX is hip to this idea, though, and that we may see it in future iterations of this app. 

THX extras

This section of the app is just straight up fun. Have you ever noticed that the THX trailers at the beginning of DVDs and Blu-ray discs can’t be repeated without stopping and starting the disc all over? We have. The short clips are fun, and good way to show off what your audio system can do in under a minute – but seeing them once is rarely enough.

THX has included links to four streaming THX trailers in 1080p with 5.1 audio in its bonus section. Since the videos are streamed, you may experience some buffering delays or see the video in less than 1080p.

THX has also included the “deep note” audio in 5.1 sound as a file embedded in the app – no buffering required. The same goes for the THX Moo Can sound clip, which is significantly less impressive.

Finally, THX provides “Ask Tex,” a sort of online support system that allows emailed questions and a hot-link to an FAQ page, should you run into trouble.


We experienced very few issues with the test version of the THX tune-up app, but we did have trouble with the app crashing on us when we used the Color and Tint camera filter feature. Pressing the back button – which should have returned us to the previous screen – resulted in our being kicked out of the app. Thankfully, the app takes almost not time to load, so we weren’t all that put off.


The THX Tune-Up app puts all of the knowledge and tools necessary for basic TV calibration in the palm of your hand. If you’ve been wanting to get the best possible performance from your TV without having to buy expensive discs or equipment you’ll probably only use a few times in your life, this app is the answer. It is comprehensive, extremely easy to use and, most importantly, effective.

We’d be a little happier if Apple’s Digital A/V adapter cable wasn’t so expensive (and, for most folks, a uni-tasker), but we can’t fault THX for that. We were also hoping for a little more from the audio section, but those wishes will probably come true with future versions of the app. For now, we’re excited to recommend this excellent app from THX. It’s probably one of the most high-value tools you can pick up for your home entertainment system.

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