Immersive Audio Technology Available to Planetariums. Part I A paper pp presented at: II International Festival of Planetariums

Transcription

1 Immersive Audio Technology Available to Planetariums. Part I A paper pp presented at: II International Festival of Planetariums By: Jeff Bowen, Bowen Technovation. Fellow-IPS, Fellow-GLPA Member of the IPS Immersive Audio Committee Abstract: In Part I of this two part presentation we explore the various hardware and software configurations and history of fimmersive i audio systems and methodologies as they apply to domed theaters. In Part II we explore immersive audio production methods and dhow to convert stereo audio music and show soundtracks to surround sound. 1

2 Why do we care about Immersive Audio? To fly sounds around the room? No. Most importantly to create space between audio objects. The more sound elements you jam into two stereo channels, the more confused the sound elements become and the less separated or less distinct. A side effect of this spatialization is that you can also place sounds in spatial locations in the room that mimic where they would be heard from in the real world. This is known as imaging. In music, a cool surround sound hi-def audio format is SACD (and new HD Blu-ray Pure Audio). Many SACD discs are now coming out and these often feature 5.1 remixes of the studio recordings. Listen to the stereo CD version of Dark Side of the Moon and then the 5.1 SACD of the same songs. Stunning. Localization. With all dome video you can place (localize) the voices of on screen characters at where the characters appear on the screen rather than all the voices coming from one or two speakers. Let s face it when you hear three voices they don t all come from the same point in the room. 2

3 The Development & History- Channel Based vs Object Based So what is channel based? Monaural Recording 1 channel Stereo-2 Speakers Modern stereophonic technology was invented in the 1930s by British engineer Alan Blumlein at EMI, who patented stereo records, stereo films, and also surround sound. Stereo- Plus Subwoofer. Extract subwoofer with a crossover. Stereo- 4 Speaker Plus Subwoofer Use separate amp channels on the rear. 5.1 L-R-C-Sub-Ls-Rs is standard multichannel wav format. C channel can be re-routed to Zenith via audio processor. 7.1 L-R-C-Sub-Ls-Rs is standard multichannel wav format AC3. C channel can be re-routed to Zenith via audio processor. All the above are imaging on horizontal plane Audio Channels Processo r Inputs Amplifier Channels Speakers Channel Names (tape, hard and (Minimum) drive, Outputs computer file, video server, etc) Stereo L-R front, L-R rear L-R-C-Sub- Ls-Rs Subwoofer (s) L-R-C-Sub-Ls-Rs- Subwoofer Lss-Rss (s) 3 8.1, 11.1, etc, etc. are non-standard.

4 The Development & History- Channel Based vs Object Based So what is object based? Dolby Atmos Fraunhofer Spatial Soundwave DTS-X Object-based audio represents the sound as separate elements (e.g. singer, drums), and adds positional information to them, so they can be rendered in real-time to be played out from the correct location. Atmos Standardized di d encoded d file. Easy distribution. ib ti 10 tracks dedicated to channels 118 tracks dedicated to objects. 128 object and channel tracks available in Dolby Atmos. Up to 64 outputs. Certified or just playback. Spatial Sound Wave (SSW) Computer or other audio source machine. Up to mono 32 tracks input dedicated to 32 channels. 4

5 The Development & History- Channel Based vs Object Based So what is object based? 5

6 Channel Based Systems Most popular and common in planetariums. Mix is set regardless of number of theater channels and room. Channel based uses a set number of channels. Dependent on your system configuration. Makes for easy exchange of shows in 5.1 is the current standard. Beyond 7.1 configurations are non standard, non exchangeable. Adding speakers does not make audio more immersive, actually is a negative. Phasing problems Myth Bust- 7.1 not better unless the shows are produced in 7.1. There s no point in adding more speakers because the 5.1 mix doesn t know what to do with them. If you don t place your speakers in the right locations, your movies won t sound quite right. Samples! 00:00 and 08:27 6

7 Channel Based Systems, Non-biamplified Monaural Recording 1 channel Stereo-2 Speakers Modern stereophonic technology was invented in the 1930s by British engineer Alan Blumlein at EMI, who patented stereo records, stereo films, and also surround sound. Stereo- Plus Subwoofer. Extract subwoofer with a crossover. Stereo- 4 Speaker Plus Subwoofer Use separate amp channels on the rear. 5.1 L-R-C-Sub-Ls-Rs is standard multichannel wav format. C channel can be re-routed to Zenith via audio processor. 7.1 L-R-C-Sub-Ls-Rs is standard multichannel wav format. C channel can be re-routed to Zenith via audio processor. 8.1, 11.1, 1 etc, etc. are non-standard. 7

8 Channel Based Systems Non-biamplified 8

9 Channel Based Systems, Biamplified 9

10 Creative Use of Channels Samples! 00:00 and 08:27 Localized dialog Localized sound effects Room ambience-reverb-delays Space between musical elements-imaging Off screen action localization Convert stereo to surround??? 10

11 Object Based. So what is object based? Dolby Atmos Fraunhofer Spatial Soundwave DTS-X Object-based audio represents the sound as separate elements (e.g. singer, drums), and adds positional information to them, so they can be rendered in real-time to be played out from the correct location. Atmos Standardized di d encoded d file, 10 tracks dedicated to channels 118 tracks dedicated to objects. 128 object and channel tracks available in Dolby Atmos. Certified or just playback. Spatial SoundWave Computer or other audio source machine. Up to mono 32 tracks input dedicated to 32 channels. 11

12 The Development & History- Channel Based vs Object Based So what is object based? 12

13 Object Based. Atmos. 13

14 Object Based. Spatial Sound Wave Up to 32 discrete channels of mono audio from server 14

15 Case and Technology Example Dolby Atmos The new THX?? The new standard for major motion picture. The new standard for Blu-ray. The new standard for audio production for picture. Dolby and BT developed specialized dome Atmos. Lower cost. More sensible SPL. 15

16 Bowen and Dolby Atmos 23.1 Config Config 16

17 Atmos Dome: a Bowen Project 23.1 Config Stereo-2 Speakers Config 17

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19 Bowen and Dolby Atmos 19

20 Immersive Audio Technology Available to Planetariums. Part II Production tips and tricks Speaker arrangements Converting stereo to surround in any dome. 20

21 Immersive Audio Technology Available to Planetariums. Part I A paper pp presented at: II International Festival of Planetariums By: Jeff Bowen, Bowen Technovation. Fellow-IPS, Fellow-GLPA Member of the IPS Immersive Audio Committee Read more in IPS Planetarian Sound Advice Help Me I m Surrounded, Part 1 March 2015 Download at: t h ti / / h / 21