Dolby E Multichannel Distribution System User Manual

Introduction

 

 

 

 

1.2System Considerations

1.2.1Digital I/O

The digital input and output connections on the DP571 encoder and DP572 decoder may seem unfamiliar to the first time user of a digital audio device. The Audio Engineering Society (AES) created a standard electrical interface for digital audio with a balanced XLR connector and 110Ω impedance called AES3-1995. This interface was later expanded to include an unbalanced BNC connector, 1 V peak-to-peak signal level, and 75 Ω impedance; the new standard is known as both AES3-ID-1995 and SMPTE- 276M. The DP571 encoder and DP572 decoder use this new standard for both digital audio and Dolby E electrical interface connections.

Note: These signals must be properly terminated with a 75Ω impedance at one point only. We recommend a standard video terminator.

1.2.2Video Reference

One of Dolby E’s most significant features is that the audio and video frame rates are identical. The DP571 encoder and DP572 decoder both require a reference video signal to lock the audio and video at frame boundaries. Standard black burst or color bars can be used as reference video if they are locked to the plant reference. A passive loop- through connection on the encoder and decoder can properly terminate the reference signal or distribute it to multiple devices.

Note: This reference signal must be terminated with a 75Ω impedance on the last device in the signal chain.

1.2.3Signal Characteristics

Although the Dolby E stream is carried on a standard AES pair, its format is different than that of a conventional digital audio signal. The PCM audio that normally comprises a digital audio signal is encoded, along with metadata and time code, into the Dolby E bitstream. The resulting data no longer directly represents the audio. Since a standard Dolby E signal can appear to the unwitting observer as a clipped or distorted digital audio signal, this section explains what to expect when measuring or monitoring a Dolby E signal.

For example, a VTR’s meters indicate a digital full-scale signal when recording or play- ing a Dolby E stream and the clip indicators may flash intermittently. Dolby E uses the entire audio payload of an AES pair, which creates the appearance of full-scale audio on the VTR. The Dolby E signal sounds like full-scale noise when monitored through speakers or headphones; this is useful to quickly verify the VTR is receiving a Dolby E signal.

To simplify working with these new signals and to allow for more detailed analysis, Dolby Laboratories has recently introduced the DM100 Portable Audio Monitor. This hand-held unit displays metadata parameters (see Section 3.2.4) and decodes Dolby E, Dolby Digital, and PCM bitstreams. The decoded audio can be monitored through an internal speaker or through user-supplied headphones.

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Dolby Laboratories DP572, DP571 user manual System Considerations, Digital I/O, Video Reference, Signal Characteristics
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DP571, DP572 specifications

Dolby Laboratories has long been a pioneer in audio and video technology, continuously pushing the boundaries of entertainment experiences. Among their range of innovative products, the Dolby DP572 and DP571 audio processors stand out as powerful tools for commercial cinema and installation applications. These devices are designed to enhance the overall sound experience in theaters, auditoriums, and other large venues, making them crucial for delivering high-quality audio.

The Dolby DP572 is a multi-channel audio processor that supports 7.1 surround sound configurations. It is equipped with advanced Dolby technologies, including Dolby Digital, Dolby Digital Plus, and Dolby TrueHD. This versatility allows filmmakers and sound engineers to create immersive soundscapes that bring an added layer of realism to the viewer's experience. One of the salient features of the DP572 is its advanced processing capabilities, which include automatic calibration, loudness control, and extensive equalization options, ensuring that the sound quality is optimized for any environment.

On the other hand, the Dolby DP571 is a companion processor designed primarily for applications that require flexible audio routing and management. It features the same high-quality audio processing as the DP572 but focuses more on signal management, making it ideal for venues that may need to adapt their audio setup frequently. The DP571 supports both analog and digital audio inputs and outputs, providing versatility for various sound systems. Both units feature user-friendly interfaces, making them accessible for system integrators and operators alike.

In terms of connectivity, both processors boast multiple inputs and outputs, allowing seamless integration with existing audio systems and peripherals. They also support industry-standard audio formats, making them compatible with a wide range of content sources. Signature Dolby technologies, such as dialogue enhancement and surround sound synthesis, ensure that even the most complex audio tracks are rendered with precision.

In summary, the Dolby DP572 and DP571 audio processors are essential components for any cinema or professional audio setup. Their advanced features, compatibility with multiple audio formats, and the legendary sound quality synonymous with Dolby make them invaluable tools for creating immersive audio experiences that captivate audiences. Whether used in conjunction or independently, these processors deliver the high-fidelity sound that is key to modern entertainment.
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