Tom Holman’s eXperiment: The THX Story

Back when home cinema was a geeky niche, and not the ubiquitous living room fixture it is today, three letters carried almost mythical weight: THX. For AV enthusiasts and cinephiles, that tiny badge on the front of an amplifier, or on a pair of speakers, didn’t just guarantee performance; it signified something more profound, something from a long time ago in a galaxy far, far away…

Guy Singleton, founder of award-winning custom installation company Imagine This, and creator of The Cinema Designer (TCD), a software suite used by AV pros to create sonically perfect home cinemas, was just six when his grandfather took him to see Star Wars.

That was it, I was hooked, I remember that opening scene, with the rebel blockade runner being chased by the absolutely huge star-destroyer. It totally blew me away.

Singleton’s subsequent love of Star Wars led him directly to THX, Skywalker Sound and Lucasfilm. A generational path well-trodden, I suspect. “I attended and completed my THX audio and video training based solely on this moment in my life,” he confides. “That then led to my business, where I design and build theatres. Also, TCD was born from that genesis moment; it's been such an influential part of my life… I really owe that day with my grandfather more than he or anyone could ever know.”

Lucasfilm sound designer Ben Burtt with THX creator Tom Holman (right) in the original THX cinema.

THX began life not as a brand but as a solution, and then it became a calling. In the early eighties, George Lucas, unhappy with the inconsistencies of theatrical audio – and believe me, most cinemas sounded very bad back in the day – was inspired to create a standard for theatrical audio playback. The idea was that cinemas could adopt it to ensure audiences experienced his films as they were crafted at Skywalker Sound. THX was named not after Lucas’s dystopian sci-fi directorial debut, THX 1138, but the audio engineer who developed the system at Lucasfilm, called Tom Holman.

Duly christened Tomlinson Holman’s Experiment (THX), it played under the banner ‘The audience is listening’ at theatres prepared to follow the Lucas rulebook: acoustics were calibrated, background noise was controlled, and sound pressure levels were monitored. It wasn’t too long before that same audience wanted to listen at home too, and Lucasfilm was only too keen to migrate its concept into the residential space.

Once again, Holman was charged with developing the core technology that could replicate in the home what sound designers heard in the mix room. He designed an entirely new generation of speakers and electronics, including the famed THX crossover, after realising the theatrical balance was a little too bright when transplanted into the home. This re-equalisation was one of the key technologies that made Home THX so distinctive.

Home Run

The Home THX standard was born, with the Lexicon CP3 processor, the first THX component out of the gate. Many more were to follow, and every unit was THX certified. Throughout the nineties, THX Home Cinema was the benchmark for AV receivers, processors, and, perhaps to a lesser extent, loudspeakers.

For those of us covering the home theatre scene during this era, THX training wasn’t just marketing; it was gospel. I remember visiting Skywalker Ranch for in-depth seminars on room acoustics, speaker placement, and the psychoacoustics of home theatre. It was the audio equivalent of Jedi training, and for my efforts I too became THX Certified – and gifted a copy of the legendary Lucasfilm Wow LaserDisc as a reward!

For most home theatre fans, the magic of THX lay in just how immersive it could make the soundstage. It’s important to remember that at the time Dolby Pro-Logic provided just four playback channels for five loudspeakers: left, centre and right (aka L/C/R), plus a monaural surround channel, split to two rear speakers. The subwoofer channel was simply a mono mix of bass information below 100Hz from the L/C/R.

THX post processing introduced Surround Decorrelation, which altered phase and timing, creating greater ambience and diffusion. When coupled with a custom dipole loudspeaker design that provided less localisable rear surround sound, the results were, and still are, impressive. However, the advent of Dolby Digital in 1996, long before Dolby Atmos, began to challenge established THX dogma. This offered discrete channel separation, with every channel capable of a full 20Hz to 20kHz bandwidth.

With this ability to deliver controllable stereo to the rear soundstage, the desire for less localised dipole presentation began to wane. Enthusiasts argued the respective merits of point-source over diffuse speakers, while manufacturers released rear enclosures with switchable biopole/dipole operation to cope with both. Times were changing.

In its prime, the THX logo adorned the front panels of some of the most revered AV gear in the business. Denon, Marantz, Onkyo, Pioneer, Yamaha, and Integra all produced classic AV receivers, while loudspeaker makers like M&K, Klipsch, KEF, Bowers & Wilkins and Definitive Technology built models specifically to meet THX specifications.

New Direction

Joining in 2001, Laurie Fincham took Holman’s original concept for THX sound and gradually applied it to new media and evolving audio technologies. A Life Fellow of the Audio Engineering Society (AES), he joined the brand with twenty-five years of experience as Technical Director for KEF Electronics and a stint as Senior Vice President of Engineering at Infinity Systems to his credit.

He introduced the THX Certified Multimedia Program, which applied THX quality standards to PC peripherals such as desktop speakers. He then rewrote the cinema sound rulebook, creating THX Ultra and its smaller room variant THX Select. These standards were to be joined by THX Dominus, in 2020, to service dedicated, large-scale home cinemas.

I met with Fincham in 2016, where he showed me his latest toy. He called it a Steerable Line Array, and at the time, I hadn’t seen anything like it. The concept was a sound system that could be incorporated into walls or curled inside furniture; it required precious little space because it didn’t need a conventional enclosure, just a small aperture for a tiny driver to fire through. What’s more, each driver could be driven individually.

Fincham demoed a 32-driver line array. Allied to motion tracking hardware, the system was able to dynamically track a listener around a room, altering the soundstage accordingly. The technology, and derivations thereof, can now be found on soundbars and in TVs.

“What I’m doing at the moment is showing you what’s possible, there are no rules. We’re just making an engine. The car you build is up to you…”

Fincham duly created the Razer Mako, a desktop audio system which employed inventive downward-firing drivers, dubbed THX Ground Plane and Slot speakers. The THX Onyx, a portable DAC/amplifier followed, introducing the THX Achromatic Audio Amplifier (THX AAA), which promised ultra-low distortion and five times more output power than rival USB DAC/amps. As fascinating as all this was, it was clear that home cinema was no longer the only stop on the THX roadmap. Perhaps the company knew a decline in conventional home cinema separates was inevitable?

Of course, Home THX is still flying the flag for home theatre enthusiasts, but it is not in the most obvious of places. Californian audio brand Monolith remains a staunch supporter, recently adding THX Certified in-wall home theatre speaker solutions to its THX catalogue. The THX-275IW is a THX Select Certified Select in-wall speaker with a single high-excursion 6.5-inch woofer, 50mm silk dome midrange driver and 25mm silk dome tweeter. For larger rooms, it offers the Monolith THX-465IW, a 3-way in-wall speaker that’s THX Ultra Certified, adding three more 6.5-inch woofers to comfortably run at a higher SPL.

Meanwhile, Norwegian high-end brand Arendal Sound promises old-school home theatre thrills with its 1723 THX speaker series. The top-of-the-line models consist of Tower, Monitor, Centre speaker, and Surround speakers, and there’s a slightly cheaper S series, which incorporates a height speaker for Dolby Atmos. If you want a partnering subwoofer range, there’s that too.

Coming Up

So what role does THX have to play in 2025 and beyond, particularly in light of RP22, the latest guidelines for immersive audio design, created by custom install trade body CEDIA, and the Consumer Technology Association (CTA)?

Manojkumar Soni, owner and principal consultant at AV4U, a leading integration company in India, should know. He sits on the CEDIA Board of Directors and holds a raft of industry certifications, including CEDIA ESC-D, CTS, THX, HAA, and ISF. He’s also part of the CEDIA RP23 Working Group.

When asked, he’s quick to acknowledge the pivotal role that THX has played in shaping the standards of home cinema design, especially through its various installer certification programs and design guidelines. He says it’s still relevant.

“Historically, THX guidelines were widely adopted and respected across the industry for setting benchmarks in both audio and video performance,” he told me. “These guidelines continue to remain relevant today and are aligned with the latest CEDIA RP22 Recommended Practices as well as Dolby’s evolving standards.”

THX may have shifted its focus in recent years towards product certification and consumer electronics, but its foundational influence on home cinema design remains significant, he says.

“Up until 2018, THX was actively involved in training programmes in collaboration with the Home Acoustics Alliance (HAA) and the Professional Video Alliance (PVA). These were immensely popular among professionals in the home cinema domain. Today, HAA and PVA continue to offer specialised training that is highly regarded in the industry, particularly for those involved in the design and calibration of high-performance residential entertainment spaces.”

Guy Singleton of Imagine This, notes that while THX certification for products is not (“in my view”) what it was, “Dominus has breathed a little new life into that with certain manufacturers clambering for that prestigious certification – especially for subs.” So clearly THX still resonates within the home cinema industry, and those three letters could find fresh traction.

The company recently announced an expansion of its THX Spatial Audio technology in the form of THX Spatial Audio+. The latest THX renderer can be configured for any number of channels, beyond 7.1.4. THX Spatial Audio+ also offers ‘transaural speaker optimisation’ able to deliver binaural, 3D sound from even relatively small stereo speakers.

More intriguingly, THX is also currently helping set certification standards, collaborating on playback optimisation and co-developing certification for Eclipsa, the new open source 3D sound system developed by Google and Samsung. Ostensibly an alternative to Dolby Atmos and DTS: X, it is looking to offer content creators and broadcasters who use YouTube, an open-source, royalty-free platform to create immersive audio. Eclipsa is able to deliver up to 28 discrete audio channels in a single bitstream and can be fixed or dynamic. It also supports binaural rendering, making it suitable for headphone playback.

THX is a member of the Alliance for Open Media (AOMedia), which backs the Immersive Audio Model and Formats (IAMF), a cornerstone of Eclipsa Audio. It’s also working alongside the Telecommunications Technology Association (TTA) to establish a formal certification program for Eclipsa-compatible hardware. If Eclipsa gains momentum, then we might well see a return of THX-certified hardware designed around the new format. I can’t wait to see what kind of car THX helps build next.

Join the discussion here