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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  • Rankor - Saturday, March 6, 2010 - link

    Good read on THX. I thought it applied only to sound systems considering it's the THX sound I always heard at the movie theaters.

    I remember when (Loyd) was writing articles in CGW.
  • Patrick Wolf - Saturday, March 6, 2010 - link

    I acually think THX is much more pertinent to video than audio. Since good audio is a relative unknown to most and thus highly subjective the THX certification doesn't hold much ground.

    The $400 you spend on the Z-5500 THX speaker system probably does deserve certification for it's combination of sound, price, and features all rolled into one complete system. But it won't sound as good as another system that's pieced together using higher quality parts and no THX certification of any kind. Course the price is going to be a bit more.

    That $400 could start you off with a kick-ass 2.0 or 2.1 system (depending on how much you want to spend on the sub) that you could eventually expand into a truly awesome 4.1 or 5.1 surround sound system that destroys the Z-5500. Example: the B2030P's and a Dayton sub.
  • Rankor - Monday, March 8, 2010 - link

    How did you know about my Logitechs? ;)

    I actually have 5300z(s) running on 5 yrs now.
  • marraco - Saturday, March 6, 2010 - link

    I do ever do this test: I paint the screen in black, then cut a square wite rectangle, and move it all over the screen.

    If the rectangle leaves a ghostly trail, the screen is bad, and blur fast moving images.

    That is the most important quality factor to me, but I don't get a clue about it from Reviews. I wish that were better considered in reviews.
  • piasabird - Saturday, March 6, 2010 - link

    So where is the sound system? How large of a speaker is this great vibrant sound suppose to come our and fill a large living room?

    Show me the speakers?
  • gersson - Saturday, March 6, 2010 - link

    Took panasonic a whole year to make my THX badged TC-50G10 Plasma look even close to what they promised. A visit to avsforum will show how long THX made people look anemic (Magenta was WAY off)
  • Kulamata - Saturday, March 6, 2010 - link

    Very nice to see Loyd settling in so well at Anandtech. Good article/review, I've not seen anything like it anywhere else.
  • piasabird - Saturday, March 6, 2010 - link

    I was looking for a new TV and I might purchase a Samsung LN37C550.

    It has a technology called Allshare. It is suppose to be able to use Applications like an I-Phone, and share Internet TV like HULU or whatever.">

    This is a brand new Model.
  • blowfish - Saturday, March 6, 2010 - link

    I think more attention needs to be paid to images being displayed at the correct aspect ratio. With the advent of widescreen TV's, people seem only too willing to tolerate distorted images, as well as super-saturated colours. When I watch motorcycle racing, I prefer to see round things look round, but I found that it was impossible to get an otherwise fairly decent quality Sony bravia HD TV to display things correctly. I find that far more important than getting the surround sound helicopter audio right.
  • Ushio01 - Saturday, March 6, 2010 - link

    The way you put it THX sounds like Feng shui for sound.

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