Trinnov Strikes Back at Dirac with New ‘Active Acoustics’ Technology

We’ve
been covering Dirac Live room correction for years. Back in 2014, we
interviewed Dirac’s then-CEO (now Chief Product Officer), Mathias Johansson. In 2018, James Larson explained Dirac’s sophisticated calibration and setup features. In 2019, Tony
Leotta told us about Dirac Live Bass Control. Last year, I wrote about the
upcoming Dirac spatial room correction solution, which abandons the old method of
correcting one channel at a time, instead using every speaker in a system
simultaneously to optimize the reproduction of each input channel. In January
of this year, Wayde Robson explained more about this revolutionary technology,
now dubbed Dirac Live Active Room Treatment, which Audioholics founder Gene
DellaSala will be testing on the Storm Audio processor in the Audioholics Smart
Home. In theory, it could allow users to achieve top-notch sound without relying
as heavily on passive room treatment (bass traps, diffusors, and so on). Dirac
Live ART will be exclusive to Storm Audio products when it officially launches
this spring, but will become available for other manufacturers to incorporate
into their products in autumn of 2023.

  Gene and Matthew Discuss Dirac’s Spatial Room Correction Capability

Obviously
we at Audioholics are fans of Dirac, but it’s not the only player in town. If
you’re considering spending the big bucks on a Storm Audio processor, you’re
probably considering a Trinnov processor as well. The French company has been
in the audio innovation business for 20 years now, providing both hardware and
software solutions for “the world’s most advanced professional music and film
studios for production, mixing, and playback,” as well as for “thousands of
commercial cinema screens and… the finest residential home theater and stereo
systems.” YouTuber Shane
Lee, who
is a friend of Audioholics, uses a Trinnov processor
in his home theater. Last September, when Shane and Gene discussed the
game-changing potential of Dirac
Live ART,
Shane said that he expected Trinnov to announce something similar in the near
future. At the time, I thought that was just wishful thinking on Shane’s part,
but perhaps he knew something that I didn’t. Fast-forward to the 2023 ISE
(Integrated Systems Europe) conference in Barcelona (which is about to begin as
I write these words in late January), and Trinnov has announced that the company’s
exhibit at booth 2D150 will feature a “new acoustic processing technology,
based on years of research.” Trinnov described this new tech as a “digital
sound field control system” that “takes the fundamental research of Trinnov in
acoustics and signal processing to the next level and effectively eliminates
room modes.” Trinnov’s first demonstration of this new technology will be in
the context of a no-holds-barred 13.16.6 home theater system assembled in
partnership with Sony, Krix
(loudspeakers), and the Italian acoustic interior design firm Officina Acustica.

In
2023, we officially celebrate our 20th anniversary as a company. It has been an
incredible journey so far and we are proud to celebrate this with style, by
unveiling yet another groundbreaking technology. This is a major milestone in
our development, and it will further reinforce our singularity and leadership
for years to come. …We have reached a point where we believe this new
technology has the potential to redefine home theater design. It may well set a
new standard, and replace today’s best practices.

—
Arnaud Laborie, Trinnov co-founder and CEO

Like
Dirac Live, Trinnov’s Optimizer is recognized as one of the best
loudspeaker/room optimization solutions available. And like Dirac Live Active
Room Treatment, Trinnov’s new break-through innovation functions as “active
acoustics.” But they don’t work in exactly the same way. While Dirac Live ART
uses every speaker in a system, Trinnov’s solution uses large subwoofer arrays
along with a new algorithm and sophisticated processing to control the
acoustics of the room. Trinnov’s announcement stressed that this was only the
“first iteration” of the company’s new technology, so the specifics of how it
works may change over time. According to Trinnov, the new addition to the
Optimizer “will rely even more on the fundamental aspects of acoustics and
physics,” and has forced its engineering team to “return to their deepest roots
and mission of innovating in acoustic field processing.” Laborie says that the
new technology is the result of an ambitious research project that began over
six years ago, and that the company plans to roll it out selectively, based on
specific projects, before finalizing the software and eventually making it a
free upgrade for all owners of the company’s popular Altitude16 and Altitude32
home theater processors. But that’s not to suggest it’s anything less than
fully operational at this stage. And to prove it, Trinnov will be
“demonstrating the technology in an uncompromised environment, delivering the
highest possible performance,” according to Laborie. He claims that, as long as
minimum required conditions are met, Trinnov’s new innovation can “make the
room disappear.”

Traditionally,
low frequency reproduction is handled through a modal analysis where resonances
are identified in the frequency domain. Through our extensive research and
unique expertise in 3D acoustic fields, we propose something different. Our
disruptive approach seeks to fully understand and control the behavior of the
room in all its dimensions (time, frequency, and the three dimensions of space)
so that resonances are removed almost entirely and without artifacts. As our
acoustician friends will all agree, you need decent room acoustics to extract
the maximum benefit of a technology such as the Optimizer. Similarly, our 3D
Loudspeaker Remapping technology requires sensible speaker placement to perform
at its best. With this new technology, things are no different. While it will
deliver remarkable improvements in most cases, the result will be truly
unprecedented with a proper subwoofer implementation in the first place.

—
Arnaud Laborie

Trinnov
says that for the best possible low-frequency performance, “optimal design
includes individual subwoofer performance, loudspeaker layout, passive
acoustics, and digital acoustic optimization.” It goes without saying that any
audio product will perform its best when the whole room and all aspects of the
system are carefully considered using a holistic approach, and that’s precisely
what Trinnov has done with its demonstration system. The three-row, 18-seat
theater utilizes three-way, bi-amped speakers for the front stage — Krix’s MX-40 LCR modules — which feature
the Australian company’s patented horn design to provide “a uniform, constant
directivity pattern, improved frequency response, and extremely low
distortion.” The surround and overhead channels will be reproduced by sixteen
of Krix’s versatile
Hyperphonix 45 speakers. But Trinnov’s new magic will be performed by two
enormous subwoofer arrays, each comprising eight Krix Cyclonix 18-inch
subwoofers — one array at the front of the room and one at the back. That’s
right — this system includes sixteen 18-inch subs!

For power, the system
uses four of Trinnov’s own Amplitude16 power amplifiers, which allow the
smaller speakers to be powered by individual channels, while the screen
channels and subwoofers are all bridged. Of course, a sound system like this
needs an impressive picture to match, so Trinnov has selected Sony’s flagship
GTZ-380 10,000-lumen laser projector ($80,000 without a lens), to blast
images onto a 19-foot-wide acoustically-transparent screen from Screen
Research. Sony claims that the GTZ-380
is the world’s most advanced compact 4K laser projector, and is capable of
reproducing the full DCI-P3 color space without brightness loss. It uses native
SXRD 4K panels and a dual laser light source combining blue and red lasers.

Editorial Note from Matthew Poes (Senior Technical Editor, Audioholics) about Double Bass Array

The Double Bass Array is an approach originally popularized in Germany and covered extensively on the AVS forum here in the states.  It comprises an array of subwoofers placed along the front wall in a precise and symmetric arrangement.  In theory this could be accomplished with as little as two subwoofers, but the distance between the subwoofers and their distance to any boundary defines the upper bandwidth over which they can produce a planar wave.  A planar wave can be thought of as a cylinder-shaped wave instead of a spherical wave.  The key to this is that the edges of the cylinder do not reflect.  If you create a full planar bass wave from 100hz to DC, then there will be no reflections from the floor, ceiling, or side walls.  There is no front wall reflection either since the array is mounted on the wall.  This eliminates the vast majority of SBIR effects and room modes.  What is left is only the length mode.  If you copy this array on the back wall, delay the signal to the length of the room, and flip the phase, then the bass is fully canceled by the back wall.  There is now no longitudinal modes either. Because half of the subwoofers in the room are used solely for cancellation purposes, you get no output gain, and in fact, because there are now no reflections, overall bass output in the room is more akin to outdoor bass levels with no room gain.  However, given the large array requirements in the first place, this is rarely a major concern (and rarely are things absolute in acoustics).

A major drawback of the DBA is that the subwoofers must be precisely placed for the concept to work, irregularities in the room may lead to more complex reflections that disrupt the planar waves, and the number of subwoofers needed and their placement are both cost and space prohibitive.  While a very effective tactic, this approach is rarely viable in even the most sophisticated custom theaters.  Prior work by others have shown that DSP processing of the signal to each subwoofer can eliminate the precise location requirements somewhat, as outlined by Adrian Celestinos in his work on Controlled Acoustic Bass Systems (CABS) discussed here. Currently it is unknown the effectiveness of the DSP processing used by Trinnov’s new approach as patents were being processed as we went to press and no further details were possible.  I have reached out to my contacts at Trinnov and will be doing a deep dive into this approach.  I have requested the opportunity to hear this approach as well as possibly test it in my own room once the software becomes available.  It is worth noting that Trinnov will not be providing this as a public beta, rather they will focus on specific projects that can support the double bass array.  Further, the DBA approach is simply the first of many new ways in which bass acoustic control will happen.  As compared to Dirac’s approach, the main drawback of the DBA is that it is only effective to the upper limit of the subwoofers, or around 80hz.  Anywhere that bass directionality is needed would need to go to those speakers respectively and so no active control of reflections is possible. Passive treatment is needed there.  By comparison, since active cancellation signals are being sent to all appropriate speakers, DIRAC is able to work up to 750hz potentially, eliminating the need for passive treatments below that point (at least in theory).  It is possible that Trinnov will have similar capabilities in the future and I hope to continue to work with Trinnov to test each new release and bring my experience and understanding to our readership.

I also want to make a note about what this concept of active cancellation is doing qualitatively to the bass and why you should care. The most important first principle to understand is that bass reflections in a room are actually quite complex.  We really need to divide the problem up into how low frequency reflections play into our sense of speciousness and envelopment and how low frequency reflections can create interference patterns that disrupt the sound quality perception.  These are two different issues and the solution to one can potentially hurt the other.  First let’s focus on this interference issue, which is what most people understand to be room modes and speaker boundary interference effects.  Essentially, bass is bouncing off of the walls, floor and ceiling.  As it then moves past other reflections and the direct sound, it creates constructive and destructive interference or peaks and dips in the response.  Because this is a minimum phase phenomena it also causes bass to vary in the time domain, ringing at peaks and not at dips.  Overall, the average time domain effect of the reflections also causes the bass to drone on a bit.  This can cause a perceived lack of definition or tightness in the bass.  It then makes sense that if we absorb or cancel all of these reflections, the net result is smooth, clean, and right bass at every seat in the room.  Passive approaches are common but as many know, take up massive amounts of space and actually don’t work all that well below 100hz.  You end up needing to give up a ton of space to effectively absorb these reflections.  This creates a problem however, our sense of envelopment or feeling like we are inside of a larger room or space comes from lateral reflections.  Both Trinnov and Dirac are largely eliminating these.  Bass sounds like it is outside basically.  This, in and of itself, is not a good or desirable thing.  Now you could turn down the effective and keep some lateral reflections, but that still turns down the perceived sense of envelopment.  I would argue this is not such a great problem.  Perceiving that we are inside our room is not a great match to the actual venue we are trying to reproduce.  Movies rarely take place in spaces that match our theaters and typically all of the spatial cues, including the low frequency cues, are encoded in the surround track.  Musical events recorded in actual venues and recorded correctly (a big if) also contain all of the low frequency lateral reflections needed to give this sense of envelopment.  Canceling the room out and reproducing it via surround speakers and surround subwoofers is not such a bad idea. However, most studio recordings, some live recordings, and probably some movies lack the low frequency spatial cues needed to perceive this sense of envelopment.  It is likely that this concept of psychoacoustics is not that well understood or a major focus of mixing.  For many, a sense of smooth, tight, and clean bass is far more important that the sense of envelopment, and so the sound quality improvement netted through wave cancellation will outweigh the detriment it could cause. 

Bass Trap Placement Diagram – courtesy of www.arqen.com

Trinnov Presentations at ISE 2023

Trinnov CEO
Arnaud Laborie presented the company’s new
technology at ISE during a CEDIA course dedicated to low frequency reproduction
called “The Double Bass Array – Next Generation Bass.” The seminar took place Wednesday, Feb.1, at 12:30 in room CC1.4. Other relevant courses include “Subwoofer Room
Gain” by Erik
Weiderholtz, Perlisten Audio CTO, and “Infra
Bass in Private Entertainment Spaces” by Geoffrey Heinzel, partner at
Ascendo Immersive Audio GmbH.
Arnaud Laborie was also on the expert panel for
the seminar entitled “Room Acoustics for Better Bass” on Thursday, Feb.2, at
12:30. If you’re lucky enough to be attending ISE in Barcelona, and didn’t miss the
chance to be among the first to experience Trinnov’s new technology at booth 2D150, please share your demo experiences with us.
Will Trinnov’s new technology prove to be as ground-breaking and effective as
we all hope Dirac Live ART will be?

Share your thoughts in the related forum
thread below.