If you’re shopping for a new television set, you might have noticed
that some of the more expensive models available claim to be ‘THX
Certified’. This sounds very cool, undoubtedly - but what does the
phrase actually mean?
Its key point - and the reason TV brands are
so keen to crow about it - is that it’s essentially an assurance of
picture quality from an independent third party organisation with a long
and glamorous history in the movie world (details on THX's history and philosophy can be found in this separate article).
As such it clearly carries infinitely more
weight than any amount of self-serving picture quality proclamations
from the brand that’s trying to sell you its TV.
THX certification can also be found on audio devices like speakers and AV receivers, as covered in a separate article.
But the performance hoops a TV needs to jump through in order to
receive THX certification are clearly very different - as well as being
incredibly numerous!
In fact, THX has developed no less than 400 bench tests for
televisions, covering everything from motion and colour through to
greyscale gradations, contrast, sharpness and video noise handling. In
developing these tests THX has created a huge suite of test signals -
some of which have now become standards across the AV industry - as well
as state-of-the-art equipment for delivering those test signals to TVs
in sufficiently precise and controllable form.
The way the THX
Certification process works is that a brand seeking to get the THX seal
of approval on one of its TVs will first submit a set for evaluation,
usually a few months before the TV is set for commercial release; THX
does not undertake testing of all TVs that get released and then contact
the makers of the sets that make the grade.
In fact, as I discovered when I met with
THX in San Francisco earlier this year, the THX certification process
is to some extent quite collaborative. Practically no TV submitted to
THX will pass all the necessary tests at the first time of asking;
rather there will be a back and forth process where THX will explain to
the TV manufacturer while its TV isn’t hitting the required mark in
certain areas, and then the TV maker’s engineers will beaver away at
improving things before resubmitting the TV for retesting.
This process can happen repeatedly for a
specific set if a TV brand is particularly keen for that set to ship
with the THX seal of approval attached to it. A recent example of the
sort of high-end TV most likely to seek THX certification is the recently announced Panasonic TX-65CZ950, the brand’s first OLED TV.
A
big part of the THX approach is making sure that a TV it is testing is
capable of matching with only very marginal room for error the
established video standards of the day. In other words, THX - in keeping
with the cinematic history discussed in a separate article - wants a TV
it certifies to be capable of showing you a film exactly as it was
intended to look by the people who created it for a Blu-ray or DVD.
THX certified TVs even carry THX picture presets featuring picture
settings designed by THX’s engineers to achieve optimal video standards
accuracy from each particular TV.
This will, of course, sound like
a very worthy cause indeed to many serious home cinema fans, and few
would argue that THX has been a force for good when it comes to
improving the standard of AV technology and the experience of going to
the cinema.
Critics do point, though, to a couple of issues with
the THX Certification process that should be mentioned here. First,
since brands have to pay THX to have their TVs tested and certified, not
all brands seek THX certification even for TVs that might possibly have
earned it had they sought it. In other words, TVs that do get THX
Certified aren’t necessarily the only brilliant TVs in the marketplace.
Second,
it’s important to realise that THX Certification can, potentially
confusingly, be achieved for different aspects of a TV’s performance.
For instance, a TV could be certified on its 3D performance, or its 4K UHD performance, or maybe, looking ahead, on its high dynamic range (HDR) performance. So the THX Certification may not necessarily apply to every part of a particular TV’s qualities.
Finally,
while the THX drive to ensure that every TV can produce the same level
of objectively measurable accuracy is clearly admirable in many ways, it
is also arguably unprogressive where advances in TV technology are
concerned. For instance, the introduction of wide colour gamuts and high
luminance levels in some recent TV screens as they prepare for the
arrival of high dynamic range content won’t fit with THX’s current
testing procedures, which are still based around the now decades old Rec
709 colour standard. So the THX mode on a current TV will essentially
require that TV to turn off all of its exciting new picture technologies
- the stuff you probably shelled out the big bucks for - in order to
bring them back in line with Rec 709.
Having raised this issue
with THX during my meeting with them, though, I was assured that the
organisation will be introducing an HDR certification model as soon as
HDR standards have finally been formally established. And actually,
given the current confusion in the AV world over what specifications a
TV needs to deliver in order to deliver a genuine HDR experience, a THX
HDR TV certification could arguably become the most important guarantee
of quality THX has delivered to date.
By John Archer
TV/Video Expert
