Digital Factory Auditorium – Music and movies in Dolby Atmos

During the visit to the DES Studio, we talked about that the finalization of the Atmos mixes for the cinema were done in the Digital Factory Auditorium.

It is in this Auditorium of the Digital Factory that we are going today, I thank Frederic (Chief Operating Officer) and Fabrice (Sound Engineer) for their welcome and the very interesting exchange we had. The Digital Factory is equipped with 4 auditoriums from 30m2 to 110 m2, this is the largest of the 4 auditoriums we are visiting today.

The Digital Factory Auditorium is a Dolby Atmos Cinema certified auditorium.
This auditorium is the size of a cinema as you can see on the pictures.

Digital Factory Auditorium

This auditorium was built after a thorough acoustic study to guarantee the most perfect rendering possible in order to allow precise and spatial mixing over the entire bandwidth.

In June 2016 this auditorium was certified Dolby Atmos for Theater, and it was used to mix the first major film Valerian and the City of a Thousand Planets in January 2017.

Everything is designed for mixing concert films such as Mylène Farmer 2019 or Johnny Hallyday Bercy 2003 (June 3, 2021) in Dolby Atmos or for movies such as Valerian and the City of a Thousand Planets and Anna. This auditorium is used for Dolby Atmos mixes, but also for 5.1 and 7.1 formats, as well as for cinema as for TV or Netflix


The big difference between concerts and films is the complexity and number of tracks. There will be less than 100 tracks to mix for a concert compared to the 1200 tracks used in Valerian and the City of a Thousand Planets.

This difference also explains the size of the mixing console which is over 4m long and allows for 2 or 3 sound engineers to work at the same time. Each one working on a part of the soundtrack, music, sound effects, speech.

To allow for a high quality mix, you need a room that is perfectly realized.
This is the case here, with acoustics that allow for the perfect exploitation of the more than 40 speakers implemented in this auditorium.

Acoustic treatments

Everything is done to have a perfect homogeneity of the sound, with for example the first row of surround speakers close to the screen which are bigger (HMS10) than the following ones (HSM5) in order to have a better homogeneity of the sound energy with the frontals.
All these speakers have been aligned with a laser measurement. The system has been perfectly calibrated to ensure a homogeneous sound. 2 subwoofers (positioned at the rear of the auditorium) are dedicated to the bass management of the 38 surround speakers.

Two rear subwoofers for the bass management of surround speakers

To better understand the complexity of the installation, here is a description of the main equipment.

Speakers

Front speakers (Left, Right and center) : Meyer Sound Acheron 80 (picture from meyersound.com) is bassed on 15-inch woofer and a 4-inch diaphragm compression driver with an Acheron’s signature horn design. Two power is integrated with 1125 watts for the woofer and 560 watts for the high-frequency channel. The crossover point is around 580 Hz.

Surround speakers (4 speakers) : The Meyer Sound HMS10 include an 10-inch low-frequency and one 2-inch diaphragm high-frequency compression driver on a symmetrical, constant-directivity 80-degree horn powered by two-channel complementary MOSFET output stages with a total of 300 watts, and a crossover at 2.5 kHz. To have a perfect homogeneity of the sound, the first speaker close to the screen being larger than the following ones.

Surround speakers (34 speakers) : The Meyer Sound HMS5 include two 5-inch low- frequency and one 2-inch diaphragm high-frequency compression driver on a symmetrical, constant-directivity 80-degree horn powered by two-channel complementary MOSFET output stages with a total of 300 watts, and a crossover at 1.7 kHz.

2 Rear subwoofers (for the bass management of the surround) and 5 front LFE : Meyer Sound X800C, it uses two Meyer Sound long excursion, high efficiency 18-inch drivers with MOSFET output stages of 1240 watts. The X-800C delivers extended low frequency output down to 20 Hz.

MPS-488HP : 4 Power Supplies are used to supply 48 volts to all surround speakers Meyer Sound HMS5 and HMS10.

Console and worlflow

For the mixing a Pro Tools system is used with an EUPHONIX System 5 console equipped with 96 faders (12*8), the console is capable of processing 2×396 digital audio channels. Several Protools can be used for mixing, recording and as a player.

The digital/analog converters used are RME M-32 DA which offer each 32 channels in 96 kHz or 16 channels in 192 kHz with more 118 dBA of dynamic range, the digital inputs are in MADI.

The Yamaha DME64N provides tuning, bass management and calibration of all 48 speakers to achieve a perfectly balanced sound.

The Dolby RMU (Rendering and Master Unit) receives all the information from the Protools to render in Dolby Atmos and provide the signals for the front, surround and LFE speakers.

The Dolby CP850 processor is used to decode the movie soundtracks sent by the Doremi Showvault media server when showing movies. The Dolby CP850 decodes up to Dolby Atmos.

The Antelope Master Clock provides the time reference for all equipment working in digital mode to ensure perfect time consistency between all equipment

The diagram below shows the system workflow for a Dolby Atmos mix, but the system can also mix in 5.1, 7.1 or DTS-X. The MADI bridge allows the selection of the mixing mode or the use in movie playback mode. The Montone 42 convert AES67 to MADI.

Mixing in Dolby Atmos for Theater

If you want more information on how Dolby Atmos works with the use of up to 128 channels divided between the BED and the 3D sound objects, you can find all the details here.

You may have questions about the difference between an Atmos cinema auditorium and an Atmos music studio.
It is mainly the difference in the volume of the room and the number of sound sources.
The listening in a studio is more close, allowing a great precision of listening, while in an auditorium, we find a very great precision of listening but in an important volume, it may be necessary to make some adaptations on a mix from a music studio and finalized in the cinema auditorium, such as reverb adjustments or adjustment of the sound level of certain tracks or positioning in space to better cover the size of the sound space.

There is also a reference frequency response target curve that is different between Dolby Atmos Music and Dolby Atmos Cinema, so it is necessary to ensure that the reproduction of the mix is optimal in sound rendering in a theater environment. The reference level for listening is 85 dB.

To listen the qualities of this auditorium, Fabrice played an Atmos mix of music with different styles.
From the very first seconds, one is impressed by the precision, clarity and finesse of the sound in a auditorium of this size.
What is remarkable is that the speakers are not locatable, we are in the presence of a homogeneous sound space, the sounds are in front of us, on the sides, behind, above, without any sound holes, the movements are fluid and natural. There is no difference in tone or coherence between the speakers.
All styles of music come through perfectly well, the bass are exemplary, it is present, firm with energy, but perfectly in its place. There is no drag or boomy bass effect.

We are in one of the best Atmos mixing auditoriums in France, something happens when you listen to an Atmos mix in this auditorium, the sound is really magical and immerses us in a real sound universe in 3 dimensions. After this listening, it will be difficult to find this sensation in another cinema.

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