How does THX determine the optimum settings?

A projector with a THX mode: the JVC DLA-HD 750, for 3,500 GBP.

Unfortunately - but also unsurprisingly - THX keeps the exact test-criteria secret; after all, if they released the information, anyone could copy the standard. It is apparently possible, however, to gain access to the approximately 400 secret criteria by paying 5,000 dollars (approx. 3,000 GBP) and swearing to complete secrecy - complete with a signature! Of course, we haven't paid the 5,000 dollars (3,000 GBP), but we've spent a great deal of time grappling with the topic of THX.

With the JVC DLA-HD 750 projector, we were able to get a first impression of the quality of the THX seal, which left a few questions unanswered. In our opinion, the THX mode didn't deliver absolutely neutral pictures - or not, at least, in this JVC.

In the JVC projector we've just mentioned, for example, we noticed that while the projector delivered neutral, correct white, the individual primary colors weren't quite spot on. Furthermore, the chosen gamma value also raised some questions - we feel that the value of 2.2 prescribed by THX isn't ideal in every situation.

In some dark studios, people also work with values of between 2.4 and 2.6 (which correspond to the gamma characteristic of studio monitors) - in these cases, the dark areas of the picture are brightened up less, leading to a subjectively higher contrast. In the dark home-theater, viewers will benefit from this higher contrast; in the bright living room, on the other hand, the effect will fizzle out.

You cannot, as a rule, adjust the settings once you've chosen THX mode. It'd be great if the company gave the user a bit more breathing room in terms of setup - an adjustable gamma value, for example, would be a good start.

In general, however, we think that THX's approach and the amount effort they've put in deserve a lot of praise - the company's settings come much closer in many respects to a perfect picture than the factory setups do.

For inexperienced users that want to access a neutral picture at the touch of a button, the THX mode is a fine thing to have. Enthusiasts, on the other hand, will probably prefer a little more room to make their own choices.

It needn't necessarily be THX - TVs without this mode can also deliver superb pictures. The Pioneer KRP-500 comes particularly highly recommended.

With, for example, their excellent KRP-500 plasma TV , Japanese company Pioneer proves that you can still come very close to a perfect picture without THX; the Pioneer KRP-500 delivers outstanding pictures with breathtaking contrast in its excellent factory setup. Unfortunately, Pioneer has now completely given up TV-production, meaning only a few examples of the KRP-500 remain on the market. On the other hand, ever more TVs with THX mode are finding their way into the living room; you can expect Televisions.com reviews of these in the near future.

We're already working on reviews of Panasonic's TX-P 54 Z1 high-end plasma (54 inches, around 5,000 GBP, Panasonic's TX-P 50 V10 plasma (50 inches, around 1,350 GBP), which is also THX-certified, and LG's stylish 50 PS 8000 plasma (50 inches, around 950 GBP).