Techno Tidbits and Problem-solving

Dolby Digital

Dolby Digital is a compression format which records the sound of 6 channels of the theater surround system (Dolby Digital) on the movie film digital track. Of the 6 channels, the sub woofer channel is intended for bass only, and because the frequency range is smaller than the main channel, it is expressed as 5.1 channel.

Dolby Digital is the name of the Dolby surround multi-channel digital system that was developed after the Dolby Surround System and Dolby Pro Logic Surround System.

5.1 channel digital

4 channel analog

surround track

sound track (Matrix)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Dolby

Digital encoding

Dolby Digital for movie films

The number of movies made using Dolby Digital since 1992 has exceeded 300 and continues to increase. For compact disc players and laser disc digital sounds, 16 bits are used to sample the original analog audio waveform and sampling is carried out 44,100 times every second. However, because an enormous amount of recording signal data is required for the multi channel system with this method, AC-3 is used to compress the data.

In reproducing audio signals, the smaller the bit number used, the lower the sound quality. With AC- 3, drop in auditory sound quality is prevented by using masking technology and digital filtering technology based on the human auditory characteristics.

Laser disc format

Laser discs are now available on the market in large numbers. This means that the recording of different format audio signals on the laser disc raises the important question of compatibility with existing laser discs. Dolby Digital tracks on Laser discs record signals using the space of one analog audio channel so it will maintain compatibility with existing discs and players.

As shown in the following figure, the digital audio sounds of Dolby Digital discs can be played back as currently done. Analog sounds are played back by using the other channel without the Dolby Digital signals for monaural audio signals.

Analog sound

 

Dolby Digital

 

 

(Monaural)

 

 

sound

 

 

 

 

Digital

 

 

 

 

 

 

Video

 

 

 

 

 

 

sound

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

4

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10

12

14 MHz

 

 

 

 

 

 

Frequency

Comparison with Dolby Pro Logic Surround

Dolby Digital is also known as the 5.1 channel system. It is equipped with 5 channels (front left, front right, center, surround left, surround right) in the frequency range from 20 Hz to 20 kHz and an independent Low Frequency Effect (LFE) channel. The sub woofer channel is also called Low Frequency Effect (LFE).

The sub woofer channel can be used as desired to enjoy strong bass sounds.

The table on the next page shows the comparison with Dolby Pro Logic Surround effects.

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Pioneer VSX-D908TX-G, VSX-D938TX manual Techno Tidbits and Problem-solving, Dolby Digital, Laser disc format

VSX-D908TX, VSX-D908TX-G, VSX-D938TX specifications

The Pioneer VSX-D908TX, VSX-D938TX, and VSX-D908TX-G are notable entries in the realm of audio-video receivers, offering a range of advanced features and technologies that cater to both audiophiles and home theater enthusiasts. Each model encapsulates Pioneer’s commitment to audio excellence and cutting-edge technology.

The VSX-D908TX stands out with its robust power handling capabilities, delivering multiple channels of amplification for immersive sound experiences. With a power rating of 100 watts per channel across 5 channels, users can enjoy rich, detailed audio whether they're watching movies or listening to music. This model also incorporates Dolby Digital and DTS decoding, allowing for detailed surround sound reproduction. The onboard Room Calibration system helps tailor the audio output to suit the unique acoustics of any room, enhancing the listener's experience.

The VSX-D938TX takes this foundation further by providing an impressive 110 watts per channel across 7 channels. This allows for even greater sound staging, making it an excellent choice for those looking to build a more expansive home theater system. In addition, it boasts advanced video processing features, including support for various video formats and the capability to upscale standard-definition content, ensuring that viewers can enjoy their favorite shows and movies in the best possible quality. Its connectivity options further enhance versatility, offering multiple HDMI inputs, component, and composite video connections.

The VSX-D908TX-G shares many features with its counterparts but introduces a sleek, modern aesthetic that appeals to contemporary users. Its user-friendly interface is complemented by a comprehensive remote control that simplifies navigation through settings and inputs, making the overall experience comfortable and intuitive.

All three models embody Pioneer’s proprietary technologies, including Advanced Convergence technology, which enhances image clarity and reduces artifacts in digital content. Additionally, they support various audio formats like MP3, WMA, and AAC, ensuring compatibility with a range of digital sources.

Ultimately, the Pioneer VSX-D908TX, VSX-D938TX, and VSX-D908TX-G cater to a diverse audience, providing robust power, advanced decoding capabilities, and user-friendly features, making them formidable additions to any home entertainment setup. These receivers not only enrich the listening experience but also align seamlessly with modern home theater demands.