What is the main difference between Dolby AC-3 system and DTS system?

In short: The main difference is that the accuracy and capacity of the audio file of the DTS system is higher than that of the AC-3 system.

1. Only the surround sound provided by the Dolby Digital system is true stereo surround sound. The surround sound source is an independent and highly isolated two-channel stereo surround sound solved by the AC-3 decoder. It feeds signals to the left rear (Ls) and right rear (Rs) surround speakers respectively, so that the surround speakers have the same stereo effect as the front main channel speakers. The sound behind the listener can be accurately positioned to a certain point of the rear sound field. The surround sound provided by the Dolby directional logic system is only a mono sound source that is fed to the left and right rear speakers for playback. This kind of rear surround sound reproduced from mono is only surrounded by the sense of surround and lacks Sound image localization and sound image movement. For example, in the first episode of the 007 series of action film "Golden Eye", when the plane flew from the front of the reservoir to the left from the front to the back, Dolby directional logic can only easily distinguish that the plane swept from front to back, and Dolby Digital However, it can accurately determine that the plane swept from the front left to the right rear. Another example is that in the movie "Courage of the Dead", when the helicopter orbits in the air, it is difficult for the Dolby directional logic system to reproduce the sound effect of the helicopter orbiting the room. In the Dolby Digital system, this sound effect can be reproduced very realistically, giving people a real sense of stimulus, so that you can't help looking up or ducking to avoid.

2. The frequency bandwidth of the surround channel in the Dolby directional logic system is only 100Hz-7kHz, which greatly reduces the amount of information contained in the surround sound effect, and the low and high frequencies in the background music are ruthlessly limited. Therefore, the actual listening sensation is dry and dull, and the analytical power and details of the music are far from being discussed. The frequency response of the 5 channels of Dolby Digital is strictly designed in accordance with the AC-3 standard to be 2OHz-2OkHz (+ -5dB) or even wider. With the specially designed active subwoofer for the subwoofer channel, it can almost All the sounds within the audible range of people are replayed well in the range of 360 degrees from front to back, left and right, so that the whole sound field is more magnificent, and the sense of direction and presence are more prominent. Because of this feature, it is absolutely impossible to meet the requirements of Dolby Digital Surround Sound System with small surround speakers with narrow frequency range (especially satellite speakers). Otherwise, the surround sound effect of the AC-3 system will definitely be greatly reduced.

3. The 4-channel isolation of Dolby Pro Logic is very limited, generally only 3OdB, the best done will not exceed 55dB. The Dolby Digital technology completely isolates 5.1 channels with an isolation of up to 1O5dB, thus completely eliminating crosstalk between channels, making the picture and sound more coordinated, the sound image positioning more accurate and prominent, and the scene more realistic , Greatly improving the artistic appeal of the film.

4. Due to the limitation of analog technology in Dolby Pro Logic, the decoded signal of the system often has a higher noise level, which directly affects the dynamic response range of the whole machine, and greatly reduces the audible range. The Dolby Digital system has almost no background noise and a wide dynamic range. It can easily reproduce unmatched violent explosions, and it can also play a slightly inaudible sound of rain falling down. The dynamic range of its sound is several times that of the Dolby directional logic system, and the Dolby Digital Surround Sound System also allows users to change the width of their dynamic range as needed. For some friends who have narrow and small housing conditions, poor sound insulation in the room, or who often like to watch the fierce and hot action blockbuster late at night, they often have to listen to the big dynamic explosion at a lower volume. At this time, if you use Dolby Digital's low volume setting function. It can not only reasonably compress the dynamic range of the whole machine, but also make the low and medium level parts of the signal still clear and full. In addition, you can set the matching mode reasonably according to whether you choose a large, medium or small speaker, and consider whether to connect the active subwoofer and the distance from the listening position to each speaker, etc. Whether it is the size of the listening environment, the size of the speakers, the noisy and noisy day or the quiet night, we can choose the very satisfactory listening effect by adjusting the dynamic sound of the whole machine.

5. Dolby Digital has now resolved compatibility with other audio systems, including Dolby Pro Logic Surround Sound, two-channel stereo and even mono systems. Because there is a pilot signal Pilot Tone for each program mode (mono, stereo, surround sound, etc.) in its "bit stream", this allows Dolby Digital to automatically indicate this to you when it is working. The method and orientation of the program source can even compress the 5.1 channel audio content into mono and output it for playback on cable broadcasting or TV, thus solving a large number of program sources and greatly facilitating the user ’s The use, upgrade and interchange are precisely because Dolby Digital has so many advantages, so when the DVD working group was looking for an optimal audio encoding technology, it chose it as one of the two mandatory sound track formats in the disc product. One. In other words, every DVD disc on the market must have a two-channel PCM encoded audio track (compatible with CD) and Dolby Digital audio track, so Dolby Digital naturally becomes the mainstream audio source in today's home theaters .

In addition, just like Dolby Digital technology, DTS requires a special decoder built into the player or AV amplifier, and your DVD player must also be a third-generation product with DTS code reading capabilities. In other words, "DTS Digital Out" must be marked on the DVD panel. Therefore, if you already own a device with Dolby Digital, you do n’t have to feel outdated. However, if you are planning to configure a home theater, you must pay attention to entering an AV amplifier and DVD player that can broadcast Dolby directional logic, Dolby Digital, and DTS. At present, there are several types of fully compatible decoded AV power amplifiers in the Chinese market, which can be confirmed by the Dolby Digital and DTS certification marks on the panel.

DTS is the abbreviation of "Digital Theatre System", which means "digital theater system". Technically speaking, DTS is completely different from other sound processing systems including Dolby Digital. The so-called DTS audio track uses the 5.1-channel standard encoded by DTS (Digital Theater Systems). The maximum encoding traffic of DTS is the same as LPCM, that is, 48000 * 16 * 2 = 1536000bps = 1536kbps per second. Relatively speaking, the 448kbps provided by Dolby Digital (AC3), another popular multi-channel encoding system, is much larger. In other words, DTS has much less distortion during the compression of multi-channel sound . This feature makes DTS have inherent advantages in multi-channel coding systems. Dolby Digital is to store the sound effect data between the perforations of the film film. Because of space limitations, a large number of compression modes must be used, so that some sound quality has to be sacrificed. DTS solved this problem with a simple method, that is, storing the sound effect data in another CD-ROM to synchronize it with the image data. In this way, not only the space is increased, but also the data flow can be relatively large, and the CD storing the sound effect data can be replaced to play different language versions.

AC3 is Dolby Digital 2.0 (Dolby 2.0) is also 5 channels, but only two channels have sound. In the Dolby Digital 5.1 channel system, the left (L), middle (C), right (R), left rear (LS), right rear (RS) 5 channels of independent channel output sound, in addition A subwoofer channel, because its frequency range is only 1/10 of the standard channel, so it is called 0.1 channel, 5.1 channel is so named. Listening to this kind of music will give you the feeling of being in the concert hall, you can feel the direction and change of the sound, and the scene is full of sense. When playing DTS-encoded WAV, you need to change the WAV suffix to DTS. At the same time, if you are loading a CUE file, then change the CDImage.wav in the CUE file to CDImage.dts, and then you can put it with foobar.DTS-CD Just transplant DTS technology to CD, as for DTS CD, as the name implies, it is the audio Audio-CD of DTS track. The storage method is the same as that of a general music CD, with 16bits and 44.1kHz sampling frequency. It is just that the actual content recorded in the DTS CD is not the PCM sampling signal of the ordinary CD, but the DTS-encoded audio track signal. Since the DTS CD file recording format is compatible with ordinary CDs, it can be reproduced, produced and played in the same way as music CDs. Moreover, most of the DVD players and CD players with digital output function on the market currently support the direct output of DTS digital signals, and the DTS decoding equipment that most audio enthusiasts or equipment stores already have makes it more enjoyable to DTS CD can be as convenient as you like. DTS-CD generally has two sources, one is made by record companies with multi-track recording technology, and the other is the DTS track of DVD. The current DTS-CD is still not a successful audio format, because there are four more audio tracks than the ordinary CD, and the capacity is unchanged. It can be concluded that the quality of each audio track is definitely not as good as that of the ordinary CD, just to pursue a surround effect. . The 5.1 channel configuration is required to play DTS-CD, which is the usual AV home theater. The speakers are 2 main speakers (front) + 1 center + 2 surround + 1 subwoofer. Some cheap home theaters in the mall do not have a subwoofer, and that's fine. To play this format on a computer, you need WinDVD or PowerDVD, as well as virtual CD-ROM software, or just burn it on the disc, but the effect on the computer is generally not good, and few people configure 6 or even 8 channels on the computer. Speaker.

DTS uses a 6-channel surround system, which is similar to Dolby, but also has a large difference from Dolby, and is used by many theaters like Dolby.

In theaters, Dolby records sound encoding and movies together, while DTS uses a separate CD to store sounds and uses a synchronization technique to keep sounds and images consistent. At the same time, DTS stores the two back-up channels together with the film for use when there is a problem with the CD sound.

Bathroom Accessories

Dongguan Metalwork Technology Co., LTD. , https://www.diecast-pro.com