THX began life as part of LucasFilm. The brainchild of Tomlinson Holman, the initial goals for THX was to ensure that movie audiences in theaters heard the same audio that sound engineers heard in the listening booth after the final audio mix. Eventually, that goal mutated, the idea being to ensure that home theater buffs heard the same quality and levels of audio as those sound engineers.

I’ve known about THX and audio for a number of years, even attending level 1 and level 2 training they give to custom installers. That’s where I learned the importance of room acoustics, and how your listening space often affects your listening experience far more than any set of speakers or electronic gear could.

So when I learned about THX getting into the business of certifying HDTVs, I was interested. But before we dive into what goes into a THX certified panel, let’s talk about what THX does and doesn’t do.

What is THX (and What It’s Not)

Once part of LucasFilm, THX exists now an independent, privately held company. The company’s business is split into multiple segments, including training programs, hardware certification and theater design.

There’s some confusion about what THX standards actually mean. Unlike Dolby or DTS, THX tends to stay out of the business of actually altering the signal, though they have dabbled in psychoacoustic effects, such as THX Loudness Plus, which tweaks frequency response to maintain the perception of listening to the movie soundtrack in the sound booth at reference level.

However, THX doesn’t compete with Dolby or DTS in developing primary encoding standards. The training program for audio, for example, gives home theater installers knowledge and tools to design rooms that maximize the listening experience. You learn about acoustic treatments, speaker placement, audio calibration and room design.

Most people only ever see the THX logo on hardware, and think that’s where it ends. From my perspective, the training programs are much more interesting. The audio sessions I attended went into rigorous detail on room calibration, minimizing standing waves, acoustic treatments and more. While incredibly valuable for me, these sessions also highlighted to me the essential conflict about what THX is and isn’t – more on that shortly.

Isn’t THX About Logos on Audio Gear?

Most people, however, know about THX through logos on certified hardware. When you see an A/V receiver, home theater speakers or even PC speakers, there are certain characteristics they all have in common.

On the technology front, THX acts as a consultant in the audio space. For example, the slot-driven speakers used in the THX certified Razer Mako speakers was actually designed by THX. Interestingly, that slot design by Laurie Fincham, was actually designed for automotive speakers. As more cars actually ship with true multichannel audio setups, the slot design is able to deliver adequate sound volumes from the relatively flat areas on the center of the dashboard.

The core idea, remember, is to attempt to recreate the soundscape as the mixing engineer hears it in the sound stage through reference speakers. However, different sets of hardware may reach this goal in different environments. A set of THX certified PC speakers try to recreate that soundscape in the near field environment of a typical PC user – only a couple of feet from the speakers. If you take those THX certified PC speakers and attach them to even a modest home theater installation in a small room, you won’t get that same audio experience.

When THX certifies a piece of hardware – say, an A/V receiver – it works closely with the company building the receiver. Test criteria differ, depending on certification level. The power you need for a THX Ultra 2 certified receiver, which is supposed to fill a fairly large space at reference level is necessarily higher than that needed for a THX Select 2 receiver which is designed for a more modest living room.

At the end of the day, a company pays THX for testing, certification and the use of the logo. Companies which send their hardware through the process may end up not paying for the logo, but still end up with hardware that may be better than at the beginning of the process.

Since the logo program is a major part of THX’s revenue stream, obvious potential conflicts can occur. A company building an A/V receiver can go through all the steps of certification, but there’s no guarantee that actual retail products meet the certification. To its credit, THX does have a random test program, where they go out to retailers and buy sample gear, bring it back to the lab and test it for compliance.

Confusion Begets Controversy
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  • Ram21 - Monday, March 8, 2010 - link

    I enjoyed this piece, excellent description of THX certifications.
  • cheinonen - Monday, March 8, 2010 - link

    As much as I am loathe to defend Lexicon and the whole Oppo debate, using this as an example for THX being good or bad, at least for the reasons people have been citing, is incorrect because:

    - Oppo didn't submit the player for THX certification, for whatever reason (cost, not caring about it, I don't know) so the Oppo can't be THX certified if you buy it from Oppo
    - Lexicon did submit it for THX certification, and since the Oppo is very well designed and can pass everything that THX needs for video certification, it can be THX certified when sold by Lexicon, but not by Oppo, since Lexicon paid the fee for testing and the label
    - It's not THX certified for the audio section, as people have found that the 80Hz crossover doesn't have the correct slopes or crossover point to fit the THX standard.
    - THX has nothing to do with Lexicon using the Oppo for their player, or what it sells for, and to say that THX shouldn't certify products that conforms to their specs because someone else designed part of it (which would eliminate most gear out there), or the price is too high, would remove most THX certifications out there.

    I'd also cross over those Studio 20's at around 60 Hz or so myself, since the driver is going to have to work much harder to go full range, and the receiver will be working harder than if it was passing that material off to a subwoofer. Also, you'll be missing out on most, if not all, information below 45Hz or so unless you have double bass turned on in your receiver (not the best idea).

    I have fronts that can run down to around 24Hz for their -3 db point and I still will cross them over at 40 Hz or so, to make it easier for the amp to drive them, and I have the option to run them full range (no sub) if I am passing in analog from a turntable or a CD player, which perhaps is how you'd want to run the Studio 20's.
  • queequeg99 - Tuesday, March 9, 2010 - link

    Is there any way to determine whether a THX product is certified for audio only or video only before a company is called out like Lexicon was? I just see the THX logo on the device itself and marketroid literature touting "THX certification." I don't recall seeing any marketing or sales information on the Lexicon or other products that makes the distinction that THX is now making.

    Given the strong audio features of this device, not being very clear about what is actually being certified is seriously misleading.
  • cjb110 - Monday, March 8, 2010 - link

    I remember choosing my first home cinema receiver when DVD's were first introduced. At the time there was a lot of forum chatter about THX certification, Yamaha's stance at the time was that they did as stringent as tests as THX, and therefore didn't see the need in upping the cost just for the badge.
    Ok that's could just be PR, but the 2nd comment from the same source also stated that THX is meant for home movies, not general purpose (ie stereo music playback).
    And they we're right, at the time Yamaha's were also considered the best for 2ch music AND movie viewing...the THX'd Denons were good for movie, and so so for music.

    Point is that THX emphasises the movie experiance, sometimes to the degredation of other uses of the equipment.
  • knutjb - Sunday, March 7, 2010 - link

    THX is a marketing label implying a certain level of quality. It really just means a given product meats a predefined set of measurements. Measurements don't necessarily mean it sounds or looks good.

    If you're looking at a monitor like you would watch a movie, in a darkened room without people interrupting every minute, you will likely find what works for you, label or not.

    Same goes for sound, I didn't like the THX settings. They sounded flat and thin to me. I experimented with different settings in the store to see how much latitude I would have at home. I ended up with different equipment than I thought I was going to buy. I have small speakers running on full size and I went through a number of subwoofer crossover settings to find the best blend for my room. If the sub is set too high it won't disappear and for me 80hz is like a flashing light. Knocked it down to 60hz and it all seams to blend much better.

    Like the author, experiment with your settings for both monitor and sound and you can get very good results without spending silly money.
  • jabber - Sunday, March 7, 2010 - link

    ....after the Lexicon/Oppo scandal a few weeks ago.

    Badge for sale!
  • cosmotic - Sunday, March 7, 2010 - link

    Is in no way consistent. Temperature, quantity, and taste all differ way too much.
  • shotage - Saturday, March 6, 2010 - link

    Thanks Loyd, this was a good read.

    I look forward to a few more articles touching on similar topics i.e. sound!

    Keep up the good work!
  • idealego - Saturday, March 6, 2010 - link

    "When THX certifies a piece of hardware – say, an A/V receiver – it works closely with the company building the receiver"

    THX might want people to think this, but there is a lot of evidence to suggest that this isn't true. For example, many products are THX certified by a company that simply rebadges the product, even though the original manufacturer was never involved in THX certification and continues to sell the product under their brand without THX certification.
  • queequeg99 - Saturday, March 6, 2010 - link

    After reading about all of the foolishness surrounding the THX certification of the new Lexicon BD player, I would be hesitant to pay any material premium for THX certified equipment.

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