It’s
not stunning that Dolby Atmos could be a complicated subject, even for fanatics
who delight themselves on being the “go-to man” for house theater ideas and
explanations when family and friends wish to improve their leisure
experiences. There’s simply a number of technical info to soak up, and
numerous variables that may confound even the very best laid plans. The aim of
this text is to offer a common understanding of how Atmos works, and to
make clear the very best speaker practices to comply with when organising an Atmos house theater. We talk about the minimal variety of audio system you want in your house theater to get a correct Dolby Atmos expertise.
To
assist information us on our manner, Audioholics founder Gene DellaSala lately hosted a livestream with John Traunwieser, a recording and mixing engineer for
movie and tv, whose credit embrace work on a number of Star Wars
motion pictures, the Starvation Video games franchise, and different large titles. John supplied
distinctive insights from the attitude of knowledgeable whose job it’s to
file and blend orchestras at Fox Studios, Warner Brothers, and Sony Footage in
Los Angeles, in addition to at Air Studios and Abbey Highway in London. John has
labored with many notable composers,
together with James Newton Howard, John Williams, John Powell, Hans Zimmer, Henry
Jackman, and John Debney. He additionally works as a mixture tech on the Fox Studios
dubbing phases, aiding a number of Oscar-winning mixers. His hands-on expertise
working within the Dolby Atmos format helped us to bridge the generally sizable hole
between the intent of the artists and professionals who create our leisure
content material, and us — the oldsters at house who wish to get pleasure from that content material in a manner
that satisfies our particular person wants whereas concurrently respecting the hassle
and care that went into crafting it. Let’s get began with some background
info on what Dolby Atmos is, and the way it works.
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Dolby Atmos
Primer
Dolby
Atmos is an immersive encompass sound format that expands on earlier programs by
including top channels, ideally to be performed again by audio system mounted onto or
into the ceiling above the listeners. This permits sounds to be interpreted as
three-dimensional objects positioned wherever inside a three-dimensional sound
subject. In earlier encompass programs, every audio monitor was assigned to a channel,
correlating to a particular speaker. A 5.1-channel system used 5 audio system plus a
subwoofer. A 7.1-channel system used 7 audio system plus a subwoofer. Dolby Atmos
programs can scale up or down, including further audio system as wanted relying
upon the dimensions of the room. This implies the content material is just not tied to any particular
speaker structure or configuration.
Mixers creating Dolby Atmos content material nonetheless have the power to assign a monitor to
a particular channel, utilizing a 7.1.2 format. That is equal to a 7.1 system
with one stereo pair of top channels. This 7.1.2 structure is known as the
“mattress” for Dolby Atmos. However mixers even have the choice to assign a monitor to an
audio “object.” Every object is related to an obvious supply location in
the theater described by a set of three-dimensional rectangular coordinates
relative to the outlined audio channel areas and theater boundaries. This
permits content material creators to exactly place and transfer sounds nearly wherever,
together with overhead, to create an immersive listening expertise. Throughout
playback, the Dolby Atmos system renders the audio objects in actual time based mostly
on the recognized areas of the loudspeakers current within the theater. This fashion,
the audio object is heard as originating from its designated set of
coordinates. The know-how can adapt routinely to benefit from the
quantity and placement of the audio system, whether or not there are 5 ear-level audio system
and 4 overhead, or 24 ear-level audio system and ten overhead. For house theater,
the gold commonplace structure is 7.1.4, with seven ear-level audio system, and 4
overhead.
Dolby Atmos Speaker Layouts – 7.1.4 for house (left pic) ; Cinema Format (proper pic)
This
object-based system has an a variety of benefits over typical multichannel
know-how, by which every supply monitor is assigned to one among a set variety of
channels (5.1 or 7.1, for instance) throughout put up manufacturing. To start with,
programs like that didn’t scale up or down. If you happen to have been listening to a
7.1-channel soundtrack on a 5.1-channel system, any info being despatched to
the 2 rear encompass channels merely wouldn’t be performed again in your system.
Secondly, typical multichannel programs required the mixer to make
assumptions in regards to the playback atmosphere, which regularly didn’t align with the
speaker structure and bodily setup of the theater. Object-based know-how
permits the mixer extra inventive freedom and extra confidence that, in a correctly
set-up Atmos system, the listener will hear the content material because it was meant to be
heard. From a mixing perspective, Dolby Atmos delivers larger spatial
decision, together with the addition of the peak aircraft, giving the mixer a
considerably bigger, three dimensional “audio canvas” on which to construct the
soundscape. This area can be utilized for exaggerated results flying round
overhead, however it will probably simply as successfully be used so as to add delicate spaciousness, or
to extend readability by shifting sure sounds off-screen, or by widening the music
to create an open sonic area for dialogue.
The
following is an excerpt from an explainer from Dolby’s gaming division, going
into barely extra depth about object-based audio. It describes “static” objects, that are assigned to
particular bed-layer speaker areas, and “dynamic” objects, which will be
positioned and moved freely across the three-dimensional theater soundscape. These
ideas apply to house theater in addition to to gaming.
The
basis of Dolby Atmos relies on two forms of audio objects: static and
dynamic. Static objects are generally known as “mattress objects,” as they’re
outlined as non-moving objects which can be mapped to particular speaker areas.
Sometimes, this can be a 7.1.2 structure and is referred to easily as “the mattress,” which
corresponds to conventional non-Atmos configurations like 7.1 and 5.1. Dynamic
objects are audio objects that may freely transfer across the entirety of the
listening subject. The mattress is crucial as a result of it gives a format that’s
nonetheless relevant for audio that works greatest in a channel-based atmosphere.
Diffuse components reminiscent of atmosphere, reverb, or anything that does not want
to dynamically transfer across the room can be panned to the mattress. Moreover,
content material that was utilized in a dynamic object will be folded down into the mattress when
wanted, based mostly on prioritization and object administration. Dynamic objects are used
for exact positioning and/or free motion of content material inside the listening
area. One of the vital quick options of Dolby Atmos is the power to
signify sound on the Z axis. … This doesn’t simply enable for a top aircraft, it
really unlocks the power for sound to be reproduced in its full
three-dimensional glory. One can take some first steps and place sounds in
zones alongside the listener’s
perimeter, reminiscent of entrance, aspect, again, and above. That is applicable for many
content material and may create extraordinarily immersive and compelling experiences. The following
steps can be to strategy design from a layered strategy and embrace ideas
reminiscent of depth, frequency, proximity, perspective into creation of particular person
belongings in addition to the scene as an entire.
—
Dolby Gaming
Dolby Atmos
Content material
What
does all of this translate to in real-world listening? Plenty of that relies upon
not solely on the system used to play again the content material, but in addition on the content material
itself. Not all Dolby Atmos content material is created equal. Some titles with “Dolby
Atmos” audio use solely the mattress, with no dynamic objects. In such instances, bigger
house theaters with further audio system don’t see a lot profit in comparison with smaller
programs with fewer audio system. In response to John Traunwieser, objects are usually used for 2
issues, and two issues solely:
-
Atmospheric
sounds that you simply wish to fill the area, filling within the gaps with further
audio system. -
Level
supply sounds. These are sounds results: issues whizzing by, or specific
results that you simply wish to localize higher.
If
the combination consists completely of the 7.1.2 mattress, however you have got a much bigger system with
extra audio system — 9.1.6, for instance — the Dolby Atmos renderer can fill in these
audio system, however you gained’t hear any distinctive info within the further audio system
when you don’t have object content material within the combine. Right here’s a concrete instance. Let’s
say you have got a big, multi-row theater. The place a typical 7.1.4 structure would
have only one aspect encompass speaker on either side wall (to the left and proper of
the listening place), a big theater might need 5 aspect encompass audio system on
either side wall, in order that a number of rows of seating are coated. Now think about a
scene in a film by which a monkey swings down from a tree in entrance of you,
whooshes proper previous you, after which lands excessive up in a tree behind you. The
specificity of the sound on this scene would rely upon the way it was blended. If the
mixer used solely the mattress and no dynamic objects, you’ll discover just a few issues.
When the monkey whooshed by you, the sound would go by means of all 5 of the aspect
audio system concurrently, so there can be much less localization and a much less
practical sense of motion. If the mixer used a dynamic object for the monkey,
the sound would go by means of every of the 5 aspect audio system individually. The
algorithm is scaled within the renderer, relying on the structure. The second
distinction you’d discover would relate to the overhead sounds. The Atmos mattress solely
has one stereo pair of top channels (that’s the “.2” on the finish of seven.1.2).
So if the mixer used solely the mattress, the sounds coming from up within the treetops
would have left-to-right separation, however no front-to-back separation. You’ll
merely hear the monkey transfer from above, right down to ear degree, after which again above.
If the mixer used a dynamic object for the monkey, you’ll hear it go down
from the treetop in entrance of you, previous you at ear degree, after which up into the
treetop behind you.
There
is a number of static Atmos on the market, particularly in TV/streaming releases. This
is often if the reveals have been blended primarily in 5.1 or 7.1, after which up-mixed
to Atmos. TV and streaming mixes often have 1/tenth of the time as a
theatrical combine, so not sufficient time is spent on objects.
—
John Traunwieser
There
are just a few explanation why an Atmos combine might need restricted use of objects. John Traunwieser says that, on the subject of a movie’s
music, a number of soundtracks “aren’t
actually blended in Atmos since you don’t need
devices flying across the room. If you happen to simply stick to the mattress, (even) if
it’s an
‘Atmos’ combine, you’ll solely be listening to music by means of the mattress. Typically, he
says, a mixer would possibly make the most of objects for sure strategic issues, reminiscent of
putting a choir within the ceiling audio system to get it “off the display,” or to push
sure sounds wider off the display in order that they’re not in the best way of the
dialogue. However in lots of instances, mixers shrink back from utilizing objects as a result of a
soundtrack wealthy with object info doesn’t at all times translate down (to
channel-based codecs) in a manner that’s fascinating. Many theaters — each
skilled cinemas and residential theaters — nonetheless aren’t geared up for Atmos at
all. Atmos titles due to this fact have to be delivered to the studio in a
channel-based format, reminiscent of 7.1, along with the Atmos combine. And there
usually isn’t sufficient time or cash out there to create two completely separate
mixes. In truth, budgetary limitations are one of many major explanation why some
Atmos titles consist primarily of “mattress” materials. Creating particular person objects
for dozens of tracks and thoroughly putting them and shifting them round takes a
lot of time, and time is usually briefly provide.
You
would assume that one thing like Star Wars, or any high-budget Marvel
present, or no matter, you’d assume that the funds is out the window and also you attempt to
get the very best consequence that you really want, (however) there are such a lot of components at play. I
don’t wish to tread on any toes, nevertheless it’s a collaborative effort, and so that you
will do the very best that you would be able to in any atmosphere, however generally you have got many
completely different opinions from many alternative folks. And a number of movies that I work
on, they do these check screenings to random folks, and you then’re having a
complete different set of suggestions from random folks watching unfinished content material. And
relying on the scores of these screenings, they may return, re-cut the
movie, re-edit one thing, re-record the music, do every kind of stuff. The most effective
product that comes out is when the imaginative and prescient is obvious, and it’s executed nicely, and
everyone respects one another of their experience. And also you get the very best consequence
that manner. … There’s at all times a funds and a time constraint. Sadly, audio
is at all times the top of the method, so the movie is completed, and the audio combine is
at all times the very last thing. And for some cause, we function like high-schoolers in
that every thing will get delayed and delayed and delayed, and pushed to the final
minute. After which everyone tries to cram and get every thing accomplished to make the
launch date.
—
John Traunwieser, on the Atmos combine for The Final
Jedi
Dolby Atmos Theatrical
Combine vs Close to-Subject Combine
Many
Dolby Atmos motion pictures really get two mixes; the theatrical combine that’s performed in
the film theaters, and the near-field combine for house leisure. Any
big-budget film that will probably be launched in theaters will first get a theatrical
combine; more often than not and funds are dedicated to this combine. If funds permits, a
second near-field Atmos combine for house leisure is then created. This combine is
sometimes accomplished in a a lot shorter time frame, although the mixers have the
advantage of a accomplished theatrical combine to make use of for reference. Lastly, a 5.1/7.1 combine is perhaps made, usually in only a day or
two. Time and funds are the important thing components right here, however one other is the supposed use
of the film or TV present. If the title is being made for Netflix, Disney+, or
HBO Max, it stands to cause that the near-field combine will get probably the most time and
consideration. Typically a studio will request a theatrical combine for a streaming
title, both for archival functions, or simply in case the title ever will get a
theatrical launch. For some Atmos mixes, the Dolby renderer can do an
automated down-mix to five.1/7.1, and the outcomes are acceptable. As mentioned
earlier, that is extra seemingly when there may be much less use of objects. In different instances,
making a 5.1/7.1 combine from an Atmos combine requires extra hands-on tweaking. In accordance
to John Traunwieser,
mixers don’t at all times have the luxurious of time to hear critically to each
format and make the required changes.
So,
why the 2 Atmos mixes? Wouldn’t the theatrical combine give house theater
fanatics the very best expertise? Why make a separate near-field combine? Plenty of
it comes right down to room dimension, and the distances between the listeners and the
audio system. Dialing in a mixture for a candy spot centered on simply a few folks
is completely different from averaging out a mixture for a a lot greater room with many extra
rows. A theatrical combine may not be fairly as dialed-in
for a single spot, however general it’s higher for extra folks. And so a few of the
mixing choices will change based mostly on the atmosphere by which the combination will probably be
performed again. In a big theater, the seats on the left-hand aspect is perhaps 75
ft away from the audio system on the fitting aspect of the theater. And so panning
can’t be as exaggerated, or the folks on one aspect of the theater would possibly miss a
important quantity of knowledge. In a big theater, the mixer would possibly select
to have dialogue popping out of all three entrance LCR channels versus simply
one spot comparable to the placement of the character. In a near-field
atmosphere, the place the room is smaller, that’s much less of a difficulty and dialogue will
nearly at all times come out of the middle. These are only a few of the
concerns that mixers should be mindful when making a theatrical combine
versus a near-field combine for house leisure.
Most
folks will solely hearken to Spotify low high quality, or … no matter streaming format
it’s, and make criticisms (with out) understanding the know-how… not
understanding why it sounds dangerous.
—
John Traunwieser
Dolby Atmos Streaming High quality Compromises
Audioholics
readers certainly know that streaming media can range in high quality relying upon the
bitrates and the compression schemes used to move the digital information from
the cloud to no matter system you’re utilizing for playback. For instance, when you’re
listening on any first rate audio system, you’ll hear the distinction between
Qobuz (which delivers lossless high-resolution audio) and Spotify, which as of
November 2022, has didn’t introduce the Hello-Fi tier that it introduced in
February of 2021. Spotify nonetheless makes use of lossy compression for all streams.
Virtually all the different audio streaming providers, together with Tidal, Apple
Music, and Amazon, supply lossless audio. Sadly, lossless audio is NOT
the norm on the subject of streaming video content material. Video streaming providers
should accommodate 4K image along with audio, and there’s solely a lot
bandwidth to go round. So whereas Dolby Atmos audio is obtainable by most of the
main streaming providers (Netflix, Disney+, Amazon Prime Video, HBO Max),
your Apple TV or Roku system isn’t serving up the identical lossless audio that
you’d get from an Extremely HD Blu-ray
disc, or from a high-end server resolution like Kaleidescape. That higher-quality Dolby Atmos is
packaged inside the lossless Dolby TrueHD format first launched with the
unique Blu-ray format. Dolby Atmos on streaming providers is packaged inside
the lossy Dolby Digital Plus format, which makes use of decrease information charges. Atmos audio
is especially affected by means of lossy compression as a result of, in line with John Traunwieser, audio objects in Atmos have a
completely different bit price than the mattress channels in streaming media. He says that the
bitrate used for objects is “quite a bit decrease than you’ll assume,” and that “if
you have been to mute the mattress channels and solely hearken to the objects, you wouldn’t be very impressed with what you’re listening to.” That’s one more reason why
mixers usually don’t place crucial music info in objects. Dolby Atmos
music can sound nice, even when streamed on a tool like Apple TV. On a
Blu-ray, it may be even higher. Whereas some audiophiles will stay dedicated to
two-channel content material and equipment till the Earth crashes into the solar, others —
together with Chief Audioholic Gene DellaSala — can’t get sufficient of Atmos music (aka. Spatial Audio).
However when you spend any important time listening to music within the format, it would
develop into clear that not all of it sounds excellent.
Shopper
merchandise generally outpace skilled workflows. It’s like 8K TV. There isn’t
any, or hardly any, content material in 8K. It’s the identical factor with Dolby Atmos. So
many music studios nonetheless don’t have Atmos (mixing functionality) constructed into them.
So what’s going to find yourself taking place is you’ll combine it in no matter format is there,
whether or not it’s stereo stems, 5.1 stems… and you then ship it to a mastering
one that will up-mix and create an Atmos model based mostly on these stems. Solely
lately, in the previous few years, studios have began to improve their rooms
and get Atmos setups. So there hasn’t been a ton of content material. Clearly the
greater titles have studios which have that functionality however there may be a number of
stuff on the market that has “fake” Atmos, or simply up-mixed encompass content material that wasn’t
blended natively in Atmos. Now you have got file engineers which can be extra savvy to
Atmos, who even begin recording with extra microphones with Atmos in thoughts.
—
John Traunwieser
How
to Set Up a Dolby Atmos Dwelling Theater Speaker System
With
nice speaker depend comes nice confusion. Even within the days of 5.1-channel
audio, poor speaker positioning was a typical reason for dangerous sound in house
theaters. With Atmos, a high-performance house theater will seemingly have 11 or
extra audio system and a number of subwoofers, and it’s no surprise that this elevated
complication causes complications for these seeking the very best efficiency from
their audio programs. Inserting the audio system (and seating positions) for a Dolby
Atmos theater isn’t exhausting if in case you have a super room and full freedom to place
every thing exactly the place it ought to go. Simply hearth up a software like Audio Recommendation’s interactive house theater designer and also you’ll be accomplished earlier than you already know
it. For many of us, nonetheless, it’s not so easy. Realistically, organising an
ultimate Dolby Atmos system has its challenges. The aim of this information is just not
to say that your property theater needs to be an all-or-nothing, hardcore megabuck
system to be worthwhile. As an alternative, it’s supposed to assist clear up sure areas
of confusion, and to assist our readers perceive which Dolby Atmos “guidelines” are
crucial to comply with, and which of them will be fudged a bit. In case you have
the power to construct an ideal spec-sheet Dolby Atmos system, do it! If you happen to
should work inside the limitations of a multi-use front room, you possibly can nonetheless
obtain good outcomes if you already know what to prioritize. In such conditions, a
variety of questions will most likely come up. Do I actually need to position audio system on
or within the ceiling? What number of audio system do I would like? How necessary is it to position
the audio system the place Dolby recommends?
7.1.4 Speaker Format is the “Gold Normal” for Dwelling Cinema
As
an audio skilled, John Traunwieser
has some perception into the significance of correct speaker placement. “That’s
every thing, actually,” he mentioned. “Once you discuss listening to what the director
supposed, the artist supposed, they’re making these choices in a room that
is calibrated, and assembly sure specs that make it Atmos.” As for
the quantity and configuration of audio system, a 7.1.4 structure is the gold commonplace
that fanatics ought to shoot for each time potential. That’s to not say that
it’s the very best configuration for everybody. In case your room’s front-to-back size
is on the quick aspect, you could solely be capable to accommodate a 5.1.4 system. If
you have got an enormous theater, you would possibly profit from a 3rd pair of ceiling
audio system, further “extensive” audio system for the entrance stage, and/or a number of aspect
encompass audio system to offer protection in a multi-row setup. However 7.1.4 is the
structure that John
most frequently encounters within the studio, and it’s thought of the very best structure for a
typical house theater.
How Many Audio system for Correct Dolby Atmos Playback Youtube Dialogue
Some is perhaps tempted to simplify the set up by
utilizing just one pair of overhead audio system, however you want a minimal of 4
overhead audio system — two in entrance of the listening place and two behind — in
order to recreate the front-to-back motion and three-dimensional localization
that object-based audio was designed to offer.
Klipsch Atmos-Enabled (aka. “bouncy home”) Speaker
Like Gene, John is just not
impressed by “bouncy home” reflective-style audio system that sit at ear degree and
hearth upward, with the purpose of bouncing pontificate of the ceiling to create the
aural phantasm of top channels. Ditto for Dolby Atmos soundbars. “It’s
abusing the (Dolby Atmos) terminology,” John says. “You don’t get the identical
impact, and I wouldn’t know how one can decide a mixture listening to content material by means of a
system like that.” John’s robust advice is to make use of in-ceiling or
on-ceiling audio system, positioned as shut as potential to Dolby’s official
suggestions (with just a few minor tweaks that I’ll get to momentarily).
For
the sake of brevity, we’ll assume that you already know the place to position the 7 ear-level
audio system in a 7.1-channel system, and we’ll deal with the correct placement of
the 4 top channels to finish the 7.1.4 Dolby Atmos configuration. (One factor
to notice is that Dolby doesn’t advocate using dipole audio system for the
encompass channels in an Atmos setup. These have been generally utilized in typical
5.1 and seven.1 setups.) If you happen to do want a refresher on how one can arrange a 7-channel house theater, the Audioholics web site already has
you coated. Right here’s what Dolby has to say about using overhead audio system:
Overhead
sound is a crucial a part of the Dolby Atmos expertise. (The most effective) resolution is to
set up audio system overhead. Most typical overhead audio system with extensive
dispersion traits will work in a Dolby Atmos house theater. Dolby Atmos
audio is blended utilizing discrete, full-range audio objects that will transfer round
wherever in three-dimensional area. With this in thoughts, overhead audio system
ought to complement the frequency response, output, and power-handling
capabilities of the listener-level audio system. Select overhead audio system which can be
timbre matched as carefully as potential to the first listener-level audio system.
Overhead audio system with a large dispersion sample are fascinating to be used in a
Dolby Atmos system. This may make sure the closest replication of the cinematic
atmosphere, the place overhead audio system are positioned excessive above the listeners. If
the chosen overhead audio system have a large dispersion sample (roughly 45
levels from the acoustical reference axis over the audio band from 100 Hz to
10 kHz or wider), then audio system could also be mounted dealing with straight downward. For
audio system with narrower dispersion patterns, these with aimable or angled
components needs to be angled towards the first listening place.
The
overhead audio system needs to be at a top between two and 3 times the
vertical place of the listener-level audio system. The angle of elevation from
the listening place (to the entrance and rear) overhead audio system in a 7.1.4
reference structure needs to be 45 levels. This can be adjusted between 30 and 55
levels if wanted. See the associated picture for the popular areas of the
4 overhead audio system as seen from above. The horizontal width needs to be about
the identical because the horizontal separation of left and proper audio system, positioned at ±30 levels. If this steering is adopted,
the overhead side-to-side separation needs to be 0.5 to 0.7 of the width of the
general structure, relying on the space to the display and the entrance three
audio system, relative to the surrounds. It’s best to maintain the overhead
association centered, entrance to again, over the listening space, even when the entrance
audio system and display are at a better distance (from the listener) than the
encompass audio system.
—
Dolby
The
recommendation above from Dolby is particular to house theater Atmos programs; the
pointers for skilled cinemas are barely completely different. John Traunwieser says that the variations between the
Atmos house leisure spec and the Atmos theatrical spec are fascinating,
notably with regard to the position of top channels. “It’s a little bit
tough,” he says, “as a result of I’m producing content material that could possibly be in a theater or
for the house and I’ve to discover a hybrid of each worlds to have the ability to translate
mixes to many alternative environments.” The variations seemingly come right down to
ceiling heights. In a cinema, the excessive ceilings imply that there’s a a lot better
distance between the listener and the ceiling-mounted audio system, and between the
ceiling audio system and the aspect/rear surrounds.
For
house leisure, (Dolby’s) spec is to widen the heights to have them nearer
to the (left and proper) edges of the room. Whereas for theatrical, the heights
are pushed extra towards the middle of the rooms (once more, with regard to
left-to-right distance, not front-to-back). And customarily, each studio that
I’ve been in, the heights are usually nearer to the middle. As a result of, you
know, it will probably range relying on the peak of the room, however in case your aspect
encompass audio system are at ear top or a little bit larger, in the event that they’re too near
the ceiling audio system, you then don’t get a lot isolation or separation within the
sound, and relying on the remedy within the room and the way reflective it’s,
then it will probably simply mix collectively and you could as nicely simply have one speaker
there, it doesn’t make a lot of a distinction. So I prefer to have (the peak
channels) nearer to the middle, as do most studios, so that you could localize
what’s coming from the ceiling clearer, and what’s the aspect channels clearer.
—
John Traunwieser
Dolby Atmos Peak Audio system Placement Suggestions
Gene
additionally recommends a slight modification to Dolby’s spec with regard to the
placement of overhead audio system, however whereas John’s adjustment pushes the audio system
nearer collectively laterally, Gene’s has to do with their front-to-back
positioning relative to the listener. As quoted above, Dolby recommends a
45-degree angle of elevation from the listening place to the overhead
audio system (with 90 levels being straight up). In response to Dolby, there’s some
wiggle room there, and something from 30 to 55 levels is appropriate. Gene
recommends sticking to the smaller finish of that vary, putting the entrance Atmos
audio system 25 to 35 levels ahead from the principle listening place, and the
rear ones 25 to 35 levels behind. (For the file, he additionally positions them
laterally nearer collectively than the spec dictates, simply as John does). Gene says
that these narrower angles of elevation and tighter formation of overhead
audio system lead to a extra enveloping sound, so long as you’re utilizing audio system
with sufficiently extensive dispersion.
Dolby Atmos Peak Channel Angles
However
what occurs whenever you run into obstacles? Perhaps there’s a doorway the place you
wish to place a encompass speaker, or a light-weight fixture the place you wish to place an
in-ceiling speaker. You would possibly assume that these compromises would by no means have an effect on a
skilled like John, however even professional mixers dwell in the true world. The
Covid-19 pandemic compelled a sea change in the best way Dolby Atmos content material is created,
with many execs organising house studios and dealing remotely. By necessity,
Dolby even relaxed a few of its technical pointers, permitting mixers to work in
studios that weren’t licensed utilizing DARDT, the official Dolby Audio Room
Design Software. Maybe one of many explanation why Dolby offers a comparatively big selection
of beneficial angles for overhead speaker placement is to permit customers some flexibility.
(One other clarification has to do with the truth that people should not as delicate
to vertical and overhead location cues as we’re to horizontal location cues,
owing to the straightforward undeniable fact that our ears are on the perimeters of our heads.) In any
case, how do you proceed when you possibly can’t comply with Dolby’s pointers to the
letter? Typically you need to place the audio system the place you possibly can place them, and
on the finish of the day, you would possibly nonetheless have a fairly good-sounding system. However
when you stray dramatically from Dolby’s spec, you’ll run into issues. John
is at present constructing a house studio, and there’s a hearth within the room. I don’t
recall seeing a hearth in any of Dolby’s diagrams. Whether or not you’re constructing
an Atmos mixing studio or an Atmos house theater, these real-world challenges
will current themselves. John’s recommendation is to show to knowledgeable for assist,
and that’s exactly what he did. John sought recommendation from Gene DellaSala and
our pleasant neighborhood acoustics skilled, Matthew Poes.
It’s crucial to have knowledgeable know
what your room is, and what to work with, and the place to position (the audio system).
As a result of the common individual wouldn’t know
simply from typing in dimensions and getting a generic placement for audio system. I’m not (rigidly) following the Atmos
spec as a result of I’ve obstacles that I’ve to get round, however I’ve the
expertise to know, nicely that’s okay, I
can put them right here and will probably be okay. So there’s a wider threshold for placing
issues somewhere else. It varies relying on the room dimension and what you
have in there.
—
John Traunwieser
Dolby Atmos Q&A with John Traunwieser
Throughout
the livestream, viewers had the possibility to ask questions and get straight
solutions about matters that generally spark confusion or disagreement amongst house
theater fanatics. Among the questions have been edited for readability.
Q1.
Ought to a speaker structure match the visible Dolby Atmos renderer on Logic Professional?
That’s, if the renderer interface reveals objects within the corners of the room, do
you want audio system in these areas? Is the renderer of Logic Professional exhibiting a
legitimate spatial map of the recording? What in regards to the virtualization of sound
between audio system?
John:
“Whether or not it’s Professional Instruments or Logic or every other DAW (Digital Audio Workstation),
the panner graphic or GUI is only a generic field with dots. It’s not a
illustration of how your room needs to be laid out. It’s one thing that
engineers take a look at to pan no matter, nevertheless it’s only a generic field. In Professional Instruments
it’s a dice, and it simply offers you a common concept of the place you’re putting
one thing. In the end, you’re going to make use of your ears and pan the sound impact
or instrument to the placement that you really want. So (the GUI) is there as a information
nevertheless it’s not exhibiting you what your structure needs to be.”
Q2.
Are there some locations the place you possibly can’t place objects?
John: “Objects
will be positioned wherever you need. All the audio system will be taken benefit of,
utilizing objects.”
Q3.
Some folks advocate putting top audio system excessive up on the back and front
partitions. Is that fascinating, or ought to they be on/within the ceiling?
John:
“Each single studio I’ve ever been to has Atmos audio system on the ceiling.”
Matthew
Poes added:
Both could possibly be right, it is dependent upon the angles. The partitions make
sense when you had very low ceilings. In any other case, to get the angles proper, they
would have to be within the ceiling. So, the notion that they need to be on the
wall, or that that’s the ‘right’ place (is fake). That may work OK in
sure circumstances, however that’s not usually the popular place.
This fall.
What are your ideas about computerized up-mixing in AV receivers?
John:
“We at all times have a struggle on the subject of listening to mixes by means of client
(gear) as a result of there may be a lot further processing taking place in
receivers that’s undesired, particularly on the subject of up-mixing. As a result of
that’s whenever you’re fully falling off the map of what the unique combine was,
and basically you’re remixing it. If you happen to’re watching a 5.1-channel film however
you up-mix it to Auro or Atmos, the field is doing one thing, and it’s everybody’s
guess what it’s doing.”
Q5.
Is it necessary to you that folks hear a mixture the best way it was supposed to be
heard?
John:
“The instruments are actually out there to all of the shoppers to tweak, and folks like
tweaking with issues. And there are a number of mixes that sound horrible, and
folks assume they will make them sound higher. And generally they do sound
higher. … A bunch of mixers shrink back from objects and are very delicate on any
Atmos results, and a few go in the other way and put an excessive amount of content material
within the surrounds. Sure, you’re an artist whenever you’re creating content material and also you
have sure freedoms to do wacky issues, nevertheless it’s in the end as much as folks’s
tastes. Some might prefer it, some might not. However I believe that’s the place it comes down
to, if it’s wacky then that was the intention. And if in case you have it arrange proper,
and also you hear the content material wacky, that’s how the artist supposed it to be. If you happen to
“right” that, then it’s completely different. It could be higher; it might be worse, however
it’s completely different. The factor that I’ll preface is that lots of people don’t
know in the event that they’re listening to it the best way the artist supposed, they usually’re making
crucial choices based mostly on (what they’re listening to). That’s what drives us
(professionals) nuts. Individuals are like, ‘This sounds horrible, or, ‘Who blended
that? What have been they listening to?’ (And but these folks) should not realizing
that perhaps the AV receiver was having the ‘Live performance Corridor’ impact on. Or, you’re
listening to one thing that’s such a low bitrate that every thing sounds
compressed, with no dynamic vary, sounds harsh. And I might love for folks to
have the power to listen to it how we hear it, as a result of that’s the greatest
expertise.”
Q6.
What are your ideas about Dolby Atmos in headphones?
John:
“Atmos in headphones is basically behind when it comes to with the ability to pinpoint sounds
so that you could inform exactly the place they’re coming from. Utilizing a generic HRTF
(Head-Associated Switch Perform) doesn’t provide the localization that
bodily audio system in a room may give.”
Q7.
Do you like mixing theatrical content material, or content material for streaming and residential
theater?
John:
“There are combine choices that I’ve to make which can be compromises to make it
translate higher to a wider medium. That’s why I like theatrical content material the
greatest as a result of it has a stricter commonplace of calibration and setup. … When it
involves client merchandise, there’s a lot on the market, you possibly can’t presumably make
it sound good on every thing.”
Q8.
How necessary is system calibration? Can one calibration be used for all
codecs and supply elements?
John:
“Not all of the content material you’re listening to is in Atmos. You can be listening to
5.1 or 7.1 content material by means of your Atmos system. And if you wish to get very granular,
if you wish to hear it because the director supposed, technically it’s best to have
completely different calibrations for various codecs. The bass administration is completely different
for Atmos and Imax and 5.1/7.1. In a correctly calibrated room at 5.1/7.1, the
surrounds are down 3dB, so they need to be 82dB, not 85dB. Once you’re
calibrating an Atmos room, every thing is at 85dB, so that you’re already listening to the
encompass audio system 3dB louder than they need to be (when listening to five.1/7.1
content material). Even going backwards and forwards between an Apple TV and a Kaleidescape, I can’t use the identical calibration
as a result of they don’t sound the identical.”
Q9.
You’ve blended in plenty of completely different studios. Do all of them use a standardized Atmos
setup?
John:
“It’s nonetheless the Wild West in studios.
Relying on which studio you go to (for mixing), it may be a special
configuration.”
Conclusion on Dolby Atmos Finest Setup Practices
We’d
prefer to thank John Traunwieser
for sharing his data and perception. We hope that this dialogue helps our
readers perceive how Atmos works, and the way that informs the easiest way to arrange
a Dolby Atmos house theater. If you happen to STILL need assistance together with your Dolby Atmos Dwelling theater, you possibly can at all times do a one-on-one house theater session with Gene DellaSala, or you possibly can
contact Matthew Poes about acoustic optimization and setup of house studios,
devoted listening rooms, and residential theaters.
