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5.1-Channel Production Guidelines Dolby Laboratories Inc USA UK Dolby Laboratories Inc 100 Potrero Avenue San Francisco, CA 94103-4813 Telephone 415-558-0200 Facsimile 415-863-1373 Dolby Laboratories Inc 3375 Barham Boulevard Los Angeles, CA 90068-1146 Telephone 323-845-1880 Facsimile 323-845-1890 Dolby Laboratories Wootton Bassett Wiltshire SN4 8QJ England Telephone (44) 1793-842100 Facsimile (44) 1793-842101 Far East Dolby Laboratories International Services Inc.
5.1-Channel Production Guidelines Table of Contents List of Figures vi Chapter 1 Introduction 1.1 Historical Perspective 1.2 Dolby Digital and 5.1-Channel Audio 1-1 Chapter 2 Getting Started 2.1 Dolby Digital Encoder and Decoder 2.2 Downmixing 2.2.1 Format Compatibility 2.2.2 Channel Redirection 2.3 Dynamic Range Control (DRC) 2.4 Bass Management 2.5 Compatibility with Existing Dolby Surround Equipment 2-1 2-1 2-2 Production Environment 3.1 Room Layout/Design 3.1.1 Room Size and Shape 3.1.
5.1-Channel Production Guidelines 3.3 3.4 3.5 3.2.3 Subwoofer(s) 3.2.4 Room Layout Bass Management Level Calibration 3.4.1 Playback Levels 3.4.2 Sound Pressure Level Meter 3.4.3 Taking a First Measurement 3.4.4 Bass Redirection 3.4.5 Individual Level Calibration 3.4.6 Subwoofer Calibration Signal Delay 3.5.1 Surround Delay for Dolby Digital 3.5.2 Center Channel Delay 3.5.3 Compatibility with Dolby Surround Monitoring Chapter 4 Equipment 4.1 Consoles 4.1.1 Small Format Console 4.1.
.1-Channel Production Guidelines 5.3 Mixing 5.3.1 Center/Front Channels 5.3.2 Surround Channels 5.3.3 LFE Channel 5.3.4 Downmix - Dolby Surround Compatibility 5.3.5 Downmix - Stereo Compatibility 5.3.6 Upmixing 5.3.7 Translation to Consumer Systems 5.3.8 Production Tips 5-2 5-3 5-4 5-5 5-7 5-8 5-9 5-12 5-13 Chapter 6 Preparing the Source Delivery Master 6.1 Channel-to-Track Allocation 6.2 Channel Levels 6.3 Reference Levels 6.4 Time Code 6.5 Documentation 6.5.1 Mix Data Sheet 6.5.
5.1-Channel Production Guidelines List of Figures 2-1 2-2 3-1 3-2 3-3 3-4 3-5 3-6 4-1 4-2 4-3 4-4 Dolby Surround Encoder Dolby Surround Pro Logic Decoder Typical 5.
5.1-Channel Production Guidelines Chapter 1 Introduction These guidelines provide starting points for producing 5.1-channel audio content by explaining terms, highlighting areas where there are alternative courses of action, and clarifying outcomes that may not be immediately apparent. The multichannel audio concept originated in the film world; therefore some cinematic terms are used. 1.1 Historical Perspective 5.1-channel audio was first developed for cinema applications.
5.1-Channel Production Guidelines Introduction possible to reproduce a higher quality of sound in the cinema, it was still not easy to deliver or reproduce strong bass. The best soundtracks of the day (70 mm magnetic) had reached their maximum recording capability, so it was impossible to increase the bass without causing overload.
5.1-Channel Production Guidelines 1.2 Introduction Dolby Digital and 5.1-Channel Audio Dolby Digital (AC-3) is a perceptual audio coding system developed in 1992 to allow 35 mm theatrical film prints to carry multichannel digital audio in addition to the standard analog optical soundtrack.
5.1-Channel Production Guidelines Introduction 5.1-channel audio typically consists of five discrete, full range main channels (Left, Center, Right, Left Surround, and Right Surround) plus an optional band-limited Low Frequency Effects (LFE) channel for added bass (the .1). Dolby Digital bitstreams deliver full frequency bandwidth main channels, from 3 Hz to 20 kHz, and a limited frequency bandwidth LFE channel, from 3 Hz to 120 Hz.
5.1-Channel Production Guidelines Chapter 2 Getting Started 2.1 Dolby Digital Encoder and Decoder The discrete 5.1-channel mix will encode and decode in a Dolby Digital 5.1-channel system and remain discrete 5.1. When mixing and monitoring in 5.1, it is important to have monitors set up and calibrated correctly so the mix will play properly when decoded by the consumer. Monitoring through an encoder and decoder is important in regards to downmixing and Dynamic Range Control (DRC).
5.1-Channel Production Guidelines 2.2 Getting Started Downmixing Downmixing has two frequently interrelated applications: format compatibility and channel redirection, as described below. 2.2.1 Format Compatibility Dolby Surround-compatible, stereo, and mono mixes are often created when multichannel material is downmixed to fewer channels. It is important to check a number of aspects of each downmix to confirm that it translates as closely as possible to the original intent of the mix.
5.1-Channel Production Guidelines Getting Started Dolby Digital 5.1-channel system will hear it. Pressing Pro Logic on the DP562 downmixes the five main channels (discarding the LFE channel) to a Dolby Surroundcompatible bitstream. The downmix is then Dolby Surround Pro Logic decoded resulting in Left, Center, Right, and mono Surround channels at the outputs. Monitoring in this mode simulates how a consumer will hear the 5.
5.1-Channel Production Guidelines Getting Started Example 1: Using a properly calibrated 5.1-channel monitoring system (incorporating appropriate bass management), set the DP562 to Dolby Digital/Full. In this configuration, a 5.1-channel bitstream will reproduce all channels the way a consumer with a Dolby Digital 5.1-channel system will hear them. Pressing any of the other Listening Modes causes the DP562 to redirect audio to the outputs of the selected speaker configuration.
5.1-Channel Production Guidelines Getting Started allow the user to choose full or reduced dynamic range when listening to a Dolby Digital multichannel soundtrack. When downmixing is in use, overload protection is applied automatically. The DP562 has the capability to monitor the dynamic range compression information encoded into the Dolby Digital bitstream. For further information on Dynamic Range Control (DRC), please consult the Dolby Digital Professional Encoding Manual.
5.1-Channel Production Guidelines 2.4 Getting Started Bass Management Bass management allows the user to redirect low-frequency information from any of the five main speakers to the subwoofer; conversely, if there is no subwoofer, the LFE information can be redirected to the left and right speakers.
5.1-Channel Production Guidelines Getting Started Center, Right, Surround: LCRS) to two-channel encoding system that is delivered via stereo media, Figure 2-1. The stereo-compatible Dolby Surround encoded soundtrack is referred to as Left total, Right total or Lt/Rt. In both the analog and digital world, Dolby Surround exists on media, e.g., VHS Hi-Fi, broadcast, CD, laser disc, etc. Dolby Digital has backward compatibility with Dolby Surround encoded material.
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5.1-Channel Production Guidelines Chapter 3 Production Environment The advent of 5.1-channel audio production poses unique challenges not only for artists and audio engineers, but also for the designers and builders of audio facilities. 3.1 Room Layout/Design Significant, although not necessarily profound, differences exist between stereo and multichannel production environments.
5.1-Channel Production Guidelines 3.1.1 Production Environment Room Size and Shape Depending on the application, room size and shape will vary considerably. In multichannel audio production for broadcast, limited space in a remote truck often makes speaker placement difficult. Similarly, in a production facility designed to accommodate additional listeners such as clients, producers, and staff, increased furniture and monitoring requirements may become factors. 3.1.
5.1-Channel Production Guidelines Production Environment have Left, Center, and Right speakers placed in front, while two or more surround speakers are needed behind the engineer, Figure 3-1 Typical 5.1-Channel Room Layout Alternative room layouts for multichannel 5.1 production have been suggested by the International Telecommunication Union, as in Figure 3-4 ITU-R Recommended Listening Room.
5.1-Channel Production Guidelines Production Environment position when compromise between two arrays of surround speakers is required for area coverage. Figure 3-2 Extended Room Layout For larger critical listening environments, such as dubbing stages, several surround speakers may be used to simulate the playback environment of a movie theatre.
5.1-Channel Production Guidelines Production Environment Figure 3-3 Large Listening Room Layout All multichannel room design considerations should bear in mind requirements for producing Dolby Digital 5.1, as well as Dolby Surround. For more information on Dolby Surround and Dolby-suggested production room layouts, please review the Dolby Surround Mixing Manual, Part Number 91536, available at www.dolby.com.
5.1-Channel Production Guidelines 3.2 Production Environment Monitoring Some aspects of multichannel studio monitor setup are understood and accepted. The best approach to others is still open to debate. The following guidelines offer commonly accepted practices for setting up multichannel audio monitoring systems. 3.2.1 Front Speakers Multichannel sound systems add a center speaker to the Left/Right pair used in stereo systems.
5.1-Channel Production Guidelines Production Environment The front speakers must exhibit the same acoustic polarity. It is highly recommended that electronic signal polarity be maintained throughout the entire monitoring system. 3.2.2 Surround Speakers Whenever possible, use the same speakers all around to achieve uniformity. If this is not feasible, the surround speakers may be smaller than the front speakers but should maintain the same character; i.e.
5.1-Channel Production Guidelines 3.2.3 Production Environment Subwoofer(s) The LFE channel requires the use of at least one subwoofer in the monitor system. It is equally important to include one or more subwoofers and bass management when some or all of the speakers may not cover the deepest bass in soundtracks or music recordings. The bass from any channel that is not reproduced in the main speaker for that channel must be redirected to the subwoofer(s).
5.1-Channel Production Guidelines 3.2.4 Production Environment Room Layout The ITU-R1 has specifications for a listening room layout designed for the critical evaluation of multichannel programs. These recommendations are a good starting point for a mixing room setup as well. Aside from signal alignment, a specific geometry is described. With the Center speaker directly in front, position the L/R speakers 30° from center (forming a 60° angle) and the Surround speakers 110° off center.
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5.1-Channel Production Guidelines 3.3 Production Environment Bass Management Stereo requires the reproduction of signals from 20 Hz to 20 kHz. This is done with multi-way speaker systems, which utilize a combination of woofers and tweeters to achieve full range response. These speakers are connected via a crossover network to route the appropriate frequencies to the various speakers in the system.
5.1-Channel Production Guidelines Production Environment frequencies within the system. In this case, there are more options, as the five main channels are full range and an extra LFE channel is added. Possible combinations of speakers include five full range main speakers and a subwoofer for the LFE; five small speakers for the main channels and a subwoofer for both the LFE and all five main channels; and various combinations of the above examples. As with consumer 5.
5.1-Channel Production Guidelines Production Environment channels in need of bass management, as determined either by product design or user selection. The five main channels are then high-pass filtered at either a fixed frequency of 80 Hz or a selectable frequency of 80, 100, or 120 Hz. The summation of the LFE and any other channels is low-pass filtered at the same frequency.
5.1-Channel Production Guidelines Production Environment real-time analyzer (RTA), rather than a Sound Pressure Level (SPL) meter. If an RTA is not available, an SPL meter may be used to approximate the level. When the level is correct , most meters will read around 90–91 dB SPL C-weighted slow for the LFE channel. The difference in level is because there is no energy being reproduced for the frequencies above 120 Hz (80 Hz for consumer applications).
5.1-Channel Production Guidelines Production Environment There are three options to adjust monitor system playback levels: • Amplifier gain trim controls • Mixer’s group outputs (one for each of the L, C, R, Ls, Rs, and Sw channels) • Decoder output level trim controls The best option is to use your amplifier gain controls to set proper playback levels. This option allows you to maintain optimum signal-to-noise performance from the decoder and console.
5.1-Channel Production Guidelines Production Environment For film work, pink noise at reference level should produce a sound pressure level (SPL) of 85 dBC for each of the front channels (left, center, and right). Each surround channel should produce a sound pressure level of 82 dBC (the lower surround level is specific to film-style mixing rooms). For television work, pink noise at reference level is typically set to produce an SPL ranging from 79 dBC to 82 dBC for each of the main five channels.
5.1-Channel Production Guidelines 3.4.2 Production Environment Sound Pressure Level Meter To properly calibrate speaker levels, an SPL meter is necessary. A suitable and relatively inexpensive meter is readily available from Radio Shack ® (Tandy Electronics outside of North America). Since the relative level between channels is more important than absolute level, the accuracy of this meter is sufficient for channel balancing. For greater accuracy, more expensive meters may be used.
5.1-Channel Production Guidelines 3. 4. 5. 6. 3.4.4 Production Environment remaining approximately two seconds at each output before moving on to the next. If you do not hear pink noise in any of the five main channels as the noise cycles through that channel, check your system connections and settings. Ensure that you are sitting in your normal, proper reference listening or mixing position. Set the SPL meter to “C” weighting and “slow” response.
5.1-Channel Production Guidelines Production Environment For example, if the monitoring system consists of five satellite speakers and a subwoofer, redirect the low frequencies from the five main channels to the subwoofer output. If using small Center and Surround speakers, direct the low frequencies from those channels to the Left, Right, or subwoofer outputs. If no subwoofer is available, redirect the LFE channel to the Left and Right channel outputs.
5.1-Channel Production Guidelines Production Environment When using an RTA, proper calibration requires setting the LFE channel signal sent to the subwoofer, within its typical bandwidth of 25–120 Hz, 10 dB higher than the main channels. Refer to Figure 3-5. +10 dB datum LFE Channel +10 dB 0 dB datum Center channel 25 Hz 120 Hz 2 kHz Figure 3-5 Real-Time Analyzer (RTA) Display If an RTA is not available, setting the LFE channel higher (e.g.
5.1-Channel Production Guidelines Production Environment For future reference, if calibrating the subwoofer with an RTA, measure the level with an SPL meter and note the meter reading for the proper calibration. Use this measured value for quick checks of the system calibration in the future. 3.5 Signal Delay In addition to setting the proper monitoring levels, it is important that the sound from each speaker arrives at the listening position at the correct time.
5.1-Channel Production Guidelines Production Environment C L R Dim C Dim L Dim R Dim LS Dim RS LS RS Dim signifies distance Figure 3-6 Speaker-to-Listener Distances Since Dolby Digital is a discrete system, there is no crosstalk between channels. Although related, the delay times required for Dolby Digital are different from those required for Dolby Surround.
5.1-Channel Production Guidelines 3.5.1 Production Environment Surround Delay for Dolby Digital Determining channel delays for Dolby Digital is similar in concept to those for Dolby Surround Pro Logic, with important additional considerations. Since Dolby Digital delivers discrete signals for each channel, there is no leakage or crosstalk between channels.
5.1-Channel Production Guidelines Production Environment two measurements have been made, calculate the required delay settings for the room. Use the following formula to calculate the delays.
5.1-Channel Production Guidelines Production Environment For example, if distance C is two feet less than distance L or R, Center delay is set to 2 ms. If distance C is two feet more than distance L or R, Center delay is set to -2 ms. To make the Center delay negative, the decoder actually sets C delay to zero and adds delay to the Left, Right, Left Surround, and Right Surround outputs of up to 3 ms. This ensures coincident arrival of the Surround and front channel signals. 3.5.
5.1-Channel Production Guidelines Chapter 4 Equipment Much of the equipment used for stereo and Dolby Surround production can also be used for 5.1-channel production. There are, however, some needs specific to 5.1channel production. 4.1 Consoles When deciding on a console, it is wise to consider both current project demands and future 5.1-channel production needs. The requirements of 5.1-channel mixing consoles differ significantly from those of two-channel stereo.
5.1-Channel Production Guidelines Equipment Center, Right, Left Surround, and Right Surround) and routing to an LFE channel will offer the greatest flexibility of sound placement in the surround field. While most manufacturers provide channel bus and pan features within the console, third-party developers have created add-on outboard devices with mixing controls to properly route multichannel audio for 5.1-channel mixes.
5.1-Channel Production Guidelines 4.1.1 Equipment Small Format Console There has been an explosion of small professional consoles with enough buses to handle 5.1 mixing. While the implementation of multi-bus panning may be different, the functionality and setup of analog consoles and the newer consumer digital consoles are basically the same. Instead of panning in stereo, consoles with four or more auxiliary sends (in addition to the stereo bus prefader) can be used to place sounds anywhere in the 5.
5.1-Channel Production Guidelines Equipment 2. Surround pattern editor–allows the path of the surround pan to be changed. Select the size and shape of a circle, arc, or line. 3. Jog wheel speed manipulation–allows use of the wheel to change the speed of a pan. 4. Multiple surround formats: 2+2, 3+1, 3+2+1. 5. Master fader can be made into six-channel ganged fader. 6. Software editing available. Tascam (Current models TMD8000 and TMD4000) 1.
5.1-Channel Production Guidelines Equipment 4. Surround pattern editor–allows the path of the surround pan to be changed. Select the size and shape of a circle, arc, or line. 5. Copy control of surround pans between channels. 6. Jog wheel speed manipulation–allows use of the wheel to change the speed of a pan. 7. Software editing available.
5.1-Channel Production Guidelines Equipment Line Inputs Mixing Console Surround Section Bus Outs (Digital if Available) Digital Multitrack Auxiliary Bus Outs Amps & Speakers Figure 4-1 Interconnect Example In Figure 4-1, arrows refer to six-channel buses, and should be connected using the following channel assignments, if possible: (1) Left, (2) Right, (3) Center, (4) LFE, (5) Left Surround, and (6) Right Surround. Choice of mix outputs (Bus, Aux, Monitor, etc.) will depend on the console.
5.1-Channel Production Guidelines 4.1.2 Equipment Digital Audio Workstations Digital audio workstations (DAWs) can be employed to great effect for non-linear editing and mixing of multichannel audio. Though the vast majority of systems currently available are designed with stereo in mind, it is possible to use these workstations for multichannel applications with the help of some simple workarounds. The minimum requirement for mixing 5.
5.1-Channel Production Guidelines Equipment Figure 4-3 Typical DAW with Multichannel Panner Each of these workstations positions the surround mix through either the output bus path or the auxiliary buses. These outputs are typically routed to a multichannel digital mastering deck (e.g., ADAT or DA-88, etc.).
5.1-Channel Production Guidelines Equipment Digital Audio Workstation Console Digital Multitrack Recorder To Amps/ Speakers Figure 4-4 Typical Digital Multichannel Audio Workstation Interconnect 4.1.3 Audio Processing Equipment Audio processors can supplement fundamental sound design and enhance image placement in 5.1-channel productions.
5.1-Channel Production Guidelines Equipment production, from conception and recording to mastering and duplication. Factors to consider when purchasing audio processors for multichannel production include specifications and multichannel functionality. Multichannel processors are being developed to accommodate the production demands of film, music, and broadcast. Products that offer true multichannel processing and feature sets (e.g.
5.1-Channel Production Guidelines 4.2 Equipment Recorder/Storage The evolution of non-linear multitrack digital audio recording and editing have made multichannel production for 5.1 commercial releases attainable by a large community of audio production engineers.
5.1-Channel Production Guidelines Equipment support both a discrete 5.1-channel mix, as well as a matrix-encoded Dolby Surround (Lt, Rt) on the remaining two tracks of the eight-track media. For more information on documentation for mixing and mastering, please review the material in Chapter 6.
5.1-Channel Production Guidelines Chapter 5 Production Techniques Many traditional two-channel techniques are applicable to 5.1-channel production. Nonetheless, there is an opportunity to create more convincing and engaging listening experiences. 5.1 Microphone Techniques Prior to beginning a 5.1-channel production, consider the type and size of the environment to be created. A variety of close, distant, coincident, and spaced microphone techniques can be used to produce a natural-sounding environment.
5.1-Channel Production Guidelines 5.2 Production Techniques Recording Multitrack audio recording technology has undergone great advancements in recent decades. Today, audio professionals have an increasing number of options for recording, editing, and delivering content. The specific allocation of tracks for a 5.1channel production depends on the project and the mix.
5.1-Channel Production Guidelines 5.3.1 Production Techniques Center/Front Channels In a stereo program there is only one way to obtain a centrally placed sound image: mix the signal equally to the L/R channels. In a multichannel system, there are three ways: • Create a phantom center just as with stereo. • Use the center channel alone. • Use all three front channels equally or in varied proportion. Each approach offers advantages and drawbacks.
5.1-Channel Production Guidelines Production Techniques Signals might interact with each other causing the phantom image to conflict with the true center image. In systems using dissimilar speakers, or in cases where the listeners are seated off the central axis, the sound arrivals from all three speakers may not blend well. Differences in arrival time can cause a comb-filtering effect, shifts in tonal color, or a smearing of the image.
5.1-Channel Production Guidelines Production Techniques film industry so well also applies to multichannel mixing: Use the surround channels to enhance rather than distract from the overall experience. 5.3.3 LFE Channel What is the difference between the LFE channel and the subwoofer signal? The LFE channel is a separate, limited frequency bandwidth signal created by the mixing engineer and delivered alongside the main channels in the mix.
5.1-Channel Production Guidelines Production Techniques In theatres, the LFE channel is used in conjunction with subwoofers to supplement the capabilities of the screen speakers. In most music productions, it is unlikely there will be a technical need to use the LFE channel. Since the overall program level may be adjusted to render any proportion of bass perfectly, the LFE channel might be an advantage only in situations similar to the famous cannon shots in Tchaikovsky’s 1812 Overture.
5.1-Channel Production Guidelines 5.3.4 Production Techniques Downmix - Dolby Surround Compatibility Always check the downmix for Dolby Surround compatibility. Dolby Surround is comprised of mono surround information; therefore stereo surround information in the 5.1-channel mix will be summed and reduced in level to become compatible in the Dolby Surround downmix. While the LFE channel is used primarily for supplemental high impact effects (e.g., explosions, crashes, storms, aerial fly-overs, etc.
5.1-Channel Production Guidelines Production Techniques If the possibility of delivering the original Lt/Rt exists, this is the preferred method. If it is not possible, then mix compromises may be necessary to compensate for unwanted artifacts caused by the downmix process. 5.3.5 Downmix-Stereo Compatibility Even with the popularity of Dolby Digital and Dolby Surround systems, there will always be a need to address stereo reproduction. There are three basic ways to accomplish this.
5.1-Channel Production Guidelines Production Techniques version while retaining flexibility in the exact proportions of each channel represented in the final stereo mix. Created by Decoder This option does not create a separate mix. In this case, the decoder derives a stereo downmix based on preset formulas. When applicable, consumer decoders will apply dynamic range reduction during the downmix process to prevent overload.
5.1-Channel Production Guidelines Production Techniques version when the master is not available in the 5.1 format. The question is how to deal with this latter situation. The most obvious and best solution is the remix. If original elements such as a multitrack source tape or individual stems have been archived, then this could provide the source material to create a new 5.1 version.
5.1-Channel Production Guidelines Production Techniques In addition, many consumers do not yet have a full 5.1-channel Dolby Digital playback system, and instead connect their DTV set-top boxes' and DVD players' two-channel outputs to a stereo or Dolby Surround Pro Logic system. Under these conditions, the multichannel soundtracks will be downmixed to mono, stereo, or Dolby Surround matrix-encoded stereo.
5.1-Channel Production Guidelines Production Techniques Other Formats Dolby analog, or Dolby Stereo matrix-encoded film soundtracks were originally produced from discrete four-track master tapes. While the four tracks on these masters corresponded to L, C, R, and S, during the matrix-encoding process the results were monitored through a matrix decoder (4:2:4 monitoring) to anticipate what would actually be heard in the cinema.
5.1-Channel Production Guidelines Production Techniques requirements for mono compatibility in stereo mixes; taking this one stage further, thought must be given to how our track will sound in stereo, mono and Dolby Pro Logic, as well as 5.1. Specific attention must also be paid to the available options in dynamic range settings accessible to listeners. The key tool in the checking process will be the professional decoder, as it can mimic all of the possible listening configurations quickly and easily.
5.1-Channel Production Guidelines Production Techniques important to check the downmixes and to listen for center channel buildup or unwanted surround information from the Pro Logic decoding process. Some effects that work well to create a 5.1 mix do not work with Pro Logic decoding. The 5.1channel system is discrete, i.e., where a sound is put is where it will stay. 4. Never decode a Dolby Surround track to make it discrete. The resulting track will not properly downmix for the consumer.
5.1-Channel Production Guidelines Chapter 6 Preparing the Source Delivery Master When preparing the source delivery master, adhere to accepted standards and practices to ensure proper Dolby Digital encoding. One of the most common source delivery formats for Dolby Digital encoding is the Hi-8 mm tape used in many popular Modular Digital Multitracks (MDMs). Digital Audio Workstations (DAWs), open reel digital multitracks, and other formats are also used for this application, although infrequently. 6.
5.1-Channel Production Guidelines Preparing the Source Delivery Master channel is not used, track 4 may contain a mono Surround (S) signal. Alternative practices exist within various industries, so it is imperative to check the source and accompanying documentation. Table 6-1 Channel-to-Track Layout Example Channel Track 6.
5.1-Channel Production Guidelines Preparing the Source Delivery Master When the Surround channel is mono, allocate it to both tracks 5 and 6 with 3 dB attenuation applied to each signal. Use the following formula: Track 5 = Track 6 = 0.707 * S Follow this recommendation even when track 4 also contains the S signal, which should always be at normal level on this track. Indicate on the tape label clearly that tracks 5 and 6 each contain the S signal at -3 dB relative to their normal levels. 6.
5.1-Channel Production Guidelines 6.4 Preparing the Source Delivery Master Time Code Time code plays two important roles in preparing mixes for Dolby Digital encoding. First, it is common to use some form of SMPTE or MIDI time code for synchronizing recording machines (DA88, ADAT) and digital editors (Pro Tools or MIDI sequencing program) while recording and mixing material. It is important to be aware at the beginning of a project what the final time code delivery format will be.
5.1-Channel Production Guidelines Preparing the Source Delivery Master feeding the Dolby Digital encoder be stable and uninterrupted. Always use the time code generated from a digital source such as a DA88 or digital VTR. If unsure of the time code source, it is best to generate clean time code from a synchronizer or use a quality time code regenerator before routing the time code into the Dolby Digital encoder. 6.
5.1-Channel Production Guidelines 6.5.1 Preparing the Source Delivery Master Mix Data Sheet The purpose of a Mix Data Sheet, Appendix A is to provide all production engineers with thorough and concise media layout information. The information contained in the Mix Data Sheet should be distributed for technical parameters prior to encoding for final delivery, i.e., in production or postproduction PRIOR to the output distribution (DVD or Digital Broadcast).
5.1-Channel Production Guidelines Preparing the Source Delivery Master actions with relationship to time, level, error, or artistic consideration. In addition to hard copy, all documentation should be duplicated and affixed to the delivery media.
5.1-Channel Production Guidelines Chapter 7 Miscellaneous Information 7.1 Technical Assistance Dolby Laboratories provides technical support to content creators and encoder users in a variety of ways. Many technical documents are available for viewing or downloading on the Dolby website at www.dolby.com. Printed copies of documents may also be obtained by sending an email request to info@dolby.com with a description of the desired documents, and a complete mailing address.
5.1-Channel Production Guidelines 7.2 Miscellaneous Information Contacting Dolby Laboratories In addition to its headquarters in San Francisco, Dolby has several other offices around the world. All offices can provide information on soundtrack production and encoding. Contact Dolby from anywhere in the world via the following e-mail addresses: Address Use to -- apply for a Dolby trademark agreement (TSA). ask questions on HDTV audio production, encoding, and hdtv@dolby.com implementation issues.
5.1-Channel Production Guidelines 7.4 Miscellaneous Information Trademark Usage Dolby Laboratories encourages use of the Dolby Digital trademark to identify soundtracks that are encoded in Dolby Digital. This is an effective way to inform listeners of the soundtrack format, and the use of a standard logo promotes easy recognition in the marketplace. As with any trademark, the Dolby Digital logo may not be used without permission.
5.1-Channel Production Guidelines Miscellaneous Information If you are already a Dolby licensee and would like more information on trademark usage, please contact Dolby Laboratories. We are always happy to review artwork and assist with the proper use of our trademarks.
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Mix Data Sheet / Date Project Client Studio / Project # Producer Engineer Sampling Frequency 32 kHz 44.1 kHz 48 kHz 96 kHz Bit Resolution 16-bit 18-bit 20-bit 24-bit Time Code Format 25 fps 29.
Mastering Data Sheet / Date Project Client Studio / Project # Producer Engineer Sampling Frequency 32 kHz 44.1 kHz 48 kHz 96 kHz Bit Resolution 16-bit 18-bit 20-bit 24-bit Time Code Format 25 fps 29.
