Pulse Code Modulation (PCM) and Bitstream are two different audio formats for decoding audio.
The audio signals are decoded by the audio modes before it’s transmitted to the speaker/receiver. It’s important to decide which one of the two is a suitable option because choosing the right audio configuration can make effective use of the sound system and give you the desired result.
Although PCM and Bitstream produce the same audio quality there is a fine line between the two audio formats. It depends upon the type of decoding device since the quality varies according to the device.
When you’re deciding between PCM and bitstream, consider other factors as well such as the device compatibility and frequencies it supports.
In this guide, we’ll discuss in detail PCM and bitstream, compare both of the audio formats and come to the conclusion regarding which one is better for your Home Theater System.
Introduction to Pulse Code Modulation (PCM)
In technical terms, Pulse Code Modulation (PCM) is a transmission technique that converts the analog signal into digital form and vice-versa. All types of analog data can be digitized be it music, video, voice, etc.
In order to obtain PCM signal from an analogue signal, the signal needs to be sampled at uniform intervals. You need to perform the sampling twice as fast as the frequency of the signal you want to reproduce. Humans can hear sounds with frequencies in the range of 20 Hz- 20 kHz. Therefore, sampling is required at 40 kHz to reproduce frequencies of 20 kHz.
During sampling, the analog data is converted to a series of 0s and 1s for processing and storage. It’s quantized to the nearest possible value. Hence the reason why CD technologies are compact. When you apply pulse modulation to the binary symbols, the Pulse Code Modulation waveform is produced which is then used by the receiver.
PCM is commonly used in DVD, Blu-ray, CD, and other audio technologies. The technology has been around for more than a century and has become the standard for audio streams. Since PCM is a type of algorithm, it doesn’t matter if you’re sending either a compressed audio file or an uncompressed file. The device receives the audio signal, decodes it, and then sends it to the receiver.
Difference between PCM and LPCM
PCM is also known as linear pulse-code modulation (LPCM.)
The only difference is that the quantization levels of LPCM are in linear form whereas PCM uses logarithmic encoding. With LPCM, you obtain more sample values, which means that it can handle higher outputs.
When you’re configuring your device, you’ll be prompted to audio output settings where you‘ll find the option to set the preferred audio format to either PCM or Bitstream. When you set it to PCM, your player will then decode the audio files and once it’s done, it will be transmitted in an uncompressed form to the receivers that are connected to the sound system.
The Audio/Video receiver doesn’t have any concern with the audio file. It’s only responsible for transmitting it to the speakers to generate output.
Introduction to Bitstream:
As the name suggests, Bitstream is another audio format that reads audio input in the form of binary digits (0s and 1s) using digital cables like Coaxial cable, HDMI, or wireless. The signals are then converted into digital bits. When the digital bits are received by the audio processor, post-processing takes place according to the information encoded in these bits. The digital bits are then converted to analog signals before it’s sent to the speaker as output.
When you configure the device to bitstream transmission, the device transfers the compressed audio files to the AVR. The receiver will decode the data and un-compress it. On the other hand, when you’re using PCM, the player decodes the audio data before it’s sent to the receiver.
With bitstream transmission, you can produce surround sound formats from the device to the receiver. The surround sound system is different from the stereo system. Stereo systems have 2 speakers: left and right which means the sound is output in 2 channels while Surround sound has more than 2 channels and comes in 5-7 channel setups.
When the receiver is set to the bitstream, it will activate the AV processor for detecting the surround sound system format. The speakers would be placed left, right and center to give you the complete surround sound experience that receives from the player.
Popular codecs like Dolby Digital Plus, Dolby Digital Ex, Dolby Atmos, etc uses the bitstream transmission. One of the advantages of bitstream transmission is since it transmits compressed files there will be no bandwidth issues so one can easily take advantage of wired as well as wireless connections.
When you set up the home theater system using bitstream configuration, it may not work for all CD players. One should always consider the device computability with bitstream transmission.
Comparison between PCM and Bitstream
|Decoding||The media player is responsible for decoding the audio files and then sending them to the receiver for output||Media players transfer the compressed audio files to the receiver which decodes data.|
|Compatibility||PCM is compatible with DVD, CD, and Blu-ray players||Supports most of the sound formats.|
|Audio File||Media players perform conversion of analog signals to digital and vice-versa for sending it to the receiver||The audio files are encoded and have a unique format for digital transmission.|
|Connection||Physical connection is needed to connect the player to the receiver/speaker||The connection can either be wired or wireless provided that the media player is compatible|
|Transmission||Easily work with players and AVR that support analog to digital transmission and vice versa.||Players and receivers that support digital transmission can only work|
|Cable Support||It has got limited support for digital output/coaxial output||The support for digital optical/coaxial output goes up to 5.1|
|Secondary Audio||Offers support for Hi-resolution secondary audio channels.||Secondary audio quality is satisfactory but there are limited options.|
PCM vs Bitstream – Similarities
Although, PCM and bitstream are different audio formats both of their configurations are similar and can produce high-quality audio. If you don’t want a high-resolution codec or a secondary audio output, there isn’t much difference between the two.
- All configurations work with Blu-ray as well as DVD players without any differences. There are many players that have the option to switch between PCM and Bitstream easily. The receiver you use can work with both configurations as long as you choose the right AVR.
Moreover, both of the audio formats need to convert the audio files to analog data before it’s transmitted to the speakers to produce the desired output. The audio processing may differ, but the files will always be converted to analog format before the speakers read it.
Whether you’re playing high-res audio or standard, the speakers will have the same audio quality.
PCM vs Bitstream – Differences
Using both configurations would produce excellent audio quality. The major challenge is to set up the home theatre system because there are various factors you need to consider.
The output quality of both of the audio formats is the same but the quality of the audio file the player receives is a major difference. PCM utilizes the signals that the converter produces and codecs such as Dolby Digital and DTS. The quality isn’t affected. In contrast to PCM, Bitstream uses coded audio data but is capable of supporting different frequencies, thus allowing you to generate hi-res audio
Aside from that, there are differences in terms of compatibility. PCM is compatible with most of the devices whereas bitstream works well with devices with surround sound format. Also, PCM is connection-oriented since files transferred by the player occupy a lot of space therefore it isn’t possible to send it wirelessly.
Choosing the PCM option in Blu-Ray Disc Player
When you’re setting the Blu-ray Disc Player audio output setting to PCM, the player decodes the audio formats such as DTS/DTS-HD Master Audio and Dolby, The decoded audio signal is sent to the receiver in an uncompressed form. Consequently, the home theater/receiver won’t have to perform further decoding so the audio is sent to the speakers. You’ll notice that the display of the theater shows the term PCM/LPCM.
If you want to listen to the descriptive audio and commentaries, you’ll have to use the secondary audio feature. Let your Blu-ray player be set to PCM for excellent sound quality. The player can easily decode the audio formats without any bandwidth issues.
If you’re choosing the PCM option, there will be a few limitations that you need to be aware of. Firstly, PCM can only support a 2-channel signal over a coaxial or optical connection. This may not be a problem for those who aren’t concerned with the space capacity.
There is also a factor of compatibility. PCM is compatible with all of the players. Since the player is responsible for decoding the audio files, you may not always get a smooth sound experience.
Lastly, you can’t go wireless because PCM sends large files which are only possible via wired connection for an interruption-free transmission from the player to the receiver.
Dolby, DTS, and PCM
Media players like Blu-ray and DVD can easily read Dolby and DTS signals. These are the digital audio formats that compress information and store it on DVD or disc digitally. The un-decoded audio formats need to be decoded by the receiver to generate analog signals. However, there is another method to do so.
When the receiver reads the un-decoded audio signals, players can transform Dolby or DTS signals to uncompressed PCM. The decoded signal is then sent to the receiver through an HDMI connection or another method is to convert the signal to an analog signal via multichannel audio outputs to the receiver.
The uncompressed PCM signal has a lot of bandwidth so when you’re using a coaxial or digital optical connection from your player to the receiver, there are only two channels of PCM audio that are available. This is completely fine but if you’re talking of DTS or Dolby signals, an HDMI connection is required because it offers 8 audio channels.
Choosing the Bitstream option in Blu-Ray Disc Player
When you set the bitstream as the audio output setting, the media player sends the un-decoded audio files to the HDMI-connected receiver. The receiver decodes the signals and as a result, the receivers display Dolby TrueHD, DTS, Dolby, DTS-HD, and other formats on the screen depending upon the type of bitstream signal.
Note that the surround sound formats such as DTS:X and the Dolby Atmos are available via the bitstream option using the Blu-ray disc player. No other players can decode these formats via PCM.
If you choose the secondary audio setting feature, the player will automatically downstream the surrounding sound formats like DTS-HD/Dolby TrueHD to standard DTS/Dolby Digital and compress the signals into the bitstream bandwidth. The signals are then recognized by the receiver which decodes them and will identify that it’s a Digital Standard signal.
So, if you use this feature, you’re combining a high-resolution primary audio signal with a secondary audio signal. The player would reduce the resolution by converting from one format to another so that it can input both of the types of audio signals easily in the bitstream.
You can expect better audio output when you’re using a bitstream. Having said that, PCM and bitstream will have almost the same audio quality if you aren’t high-quality receivers with great processing power.
You have the option to choose between PCM and bitstream. Each configuration will produce the same quality of sound.
PCM vs Bitstream Output Connections:
Once you’ve chosen the desired audio settings, you need to decide the type of connections you want to use. Whether you choose an optical digital connection or coaxial, you can select the PCM vs Bitstream output option for the connections.
The bitstream output option will send surround sound signal formats to the receiver for decoding. Oh, the PCM option sends a 2-channel signal because coaxial or digital cable doesn’t provide enough bandwidth for the transfer of uncompressed and decoded sound signal as HDMI connection can.
Moreover, Dolby Digital Plus, DTS-HD master audio, or Dolby TrueHD can’t be transmitted via bitstream or PCM since HDMI is required.
What happens when you choose PCM?
Setting your TV, Blu-ray player, or other HD input to PCM decodes the audio files before sending them to the receiver. Once the decoding is done, the player transmits the uncompressed signals to the receiver.
The receiver in turn transmits the signals to the speakers for output. Basically, the PCM configuration does all the work on its own. You gain access to almost all of the audio formats as well as surround sound formats.
Bitstream however needs a complete setup in order to access the surrounding sound formats. This is where PCM becomes a clear winner.
Furthermore, PCM has two-channel distributions. So, you can enjoy the benefits of left and right speakers when you’re listening.
What happens when you choose Bitstream?
When you choose the bitstream setting, the player will decode the audio file before transferring it to the receiver. For example, if you have a satellite TV box that receives the bitstream signals, the box would decode the information first before transferring it to the TV.
This configuration is best suited for advanced home theatre systems that support the transmission of compressed files.
However, if you’re using the secondary audio configuration, there will be a downgrade in the quality of the sound and the performance as well.
When to Use PCM Audio Configuration:
Both PCM and bitstream audio configurations produce the same sound quality, convert the audio files into analog signals before sending them to the receiver. They are compatible with all media players used in today’s times. So, how can one decide when to use PCM or bitstream? Here is when you should PCM configuration:
- -When you want to unlock the high-quality secondary audio option and access the disk or broadcast you want to watch.
- -A direct connection is needed that offers speedy transmission to the output and reduces performance latency.
- -You have a home theatre system that decodes the audio files at the player instead of being decoded by the receiver.
- -You want to free your receiver from the responsibility of converting audio files.
PCM does have its benefits but in some ways, the bitstream is better. The major difference between the two is the number of channels offered. Since PCM offers two channels, the audio plays in right and left track only. If you’ve got multiple channels installed, you can easily use PCM but the only difference would be that you wouldn’t get two on the right and left with a single in the center.
PCM works with every modern player so you’ll rest assured that you’re getting excellent audio quality. PCM may not work smoothly in some cases but it provides consistently good results and it’s used commonly in modern sound systems.
When to Use the Bitstream Audio Configuration
Consider using bitstream configuration when you want to achieve the following conditions:
- You want to use the 5.1 surround sound format when you’re choosing the coaxial or digital optical connection.
- You want your sound system to be flexible when you play high-resolution audio.
- You want a receiver having a higher processing power.
- You’ve got a sound system that relies upon the receiver for audio processing power.
With Bitstream, you can enjoy the benefits of having a better audio output since the compressed files consume less bandwidth.
This means that a large amount of information can be sent to the receiver output easily. Bitstream configuration also offers the option to go wireless so you can make effective use of the processing capabilities of high-quality receivers.
Top Home Theatre Systems with Bitstream
The Polk Audio is a complete home theater system at an affordable range that is a complete package of surround sound systems.
Unlike other speakers, the Polk Audio 5.1 doesn’t only have a modern compact design but also includes a floor-standing speaker along with a 10-inch subwoofer that offers the right amount of bass for all room sizes.
The speakers are enabled with Polk’s Proprietary dynamic balance technology that ensures there is no distortion and gives you crystal clear sound.
The speakers are wall-mountable which means that you can use them as front setup, left-right set-up, or rear speakers. They are easily compatible with AV receivers and easily be upgradable to 7.1, 9.1, and many more channels.
You would need a separate AV receiver for audio amplification and processing. A 5.1 channel receiver is needed or you could add the Dolby Atmos speakers to your home theater system.
Looking for a budget-friendly and portable sound system that gives a full cinematic experience at home? Look no further than the Vizo Soundbar system! It’s fully compatible with Dolby Atmos which is one of the common audio formats found on Blu-ray discs.
With Dolby Atmos’ support, you’ll get the feel of the sound. For instance, the sound of the rain or the helicopter flying will make you feel that you’re actually in the scene.
Moreover, the Vizio Soundbar system offers three channels: Left, center, and right. To give a seamless surround sound experience, it comes with separate rear speakers along with a subwoofer for bass.
What’s amazing about the product is that you don’t need a separate receiver since the soundbar system is responsible for handling the processing and amplification. It also includes an HDMI input so you can easily connect other devices such as a media player or console.
The only downside of the sound system is that it isn’t ideal for large-size rooms. The depth and clarity of the sound aren’t as high as that found in large sound systems. However, if you’re tight on budget, you won’t regret opting for it.
Looking for a sound system that delivers top-notch acoustic performance? The Klipsch sound system is equipped with Tractrix Horn Technology that offers smooth and crystal-clear sound. It includes a linear travel suspension that is capable of reducing any sort of distortion.
The Sound system includes a wireless subwoofer that allows 2.4 GHz connectivity to deliver room-filling low frequencies without needing extra floor space. You can easily connect to your woofer no matter where you are in the room. You’ll rest assured that you’ll receive high-quality sound.
The Sound system also has the flexibility to fix the wireless speakers. Each speaker is mounted with a keyhole for easy placement.
You will have to buy a receiver and speaker cable to make the best use of the sound system.
The Definitive Technology ProCinema 6D is an entry-level wireless home theater system that brings a complete home theater experience to the home. It comes with a 6-piece system that is powered by high-end technologies.
If you’re limited on space, this surround sound home theater is what you should be looking for. The center channel comes with advanced drivers which are guaranteed to deliver high-performance and clarity. With BDS technology and Linear Response Waveguide, you’ll have a rich sound experience as if you’re in the scene.
The subwoofer has a power rating of 250 W that provides pitch-perfect bass without any vibrations or distortions.
You would be needing a good AV receiver to enjoy the benefits of the home theater system.
Focal Sib Evo is another budget-friendly system that has got the support for Dolby Atmos. It features 5 speakers along with a subwoofer.
The theater system is designed in such a way as to deliver a complete and immersive cinema system at home. The speakers have firing drivers that create various sound effects when you’re playing the Dolby Atmos soundtracks.
You’ll have to buy an Audio receiver before you start using the Cinema System. With the latest Dolby Atmos technology, the loudspeaker is designed to reproduce the horizontal as well as the vertical waves. This speaker is suitable for large rooms and is guaranteed to give you an amazing sound experience.
It takes a while to set up the complete system and you’ll be needing wires to connect individual speakers to the receiver. Once the setup is done, you’ll be able to hear the Dolby Atmos effects from the ceiling giving you an illusion that the sound is coming from the above.
PCM VS BitStream Verdict
There is no clear winner between PCM and Bit Stream because both of the transmission technologies have their own advantages and different purposes.
If you choose either of the options, it will be guaranteed to provide a high-resolution audio format. Bitstream is most commonly used since it offers versatility when it comes to choosing coaxial outputs and also has increased audio efficiency. Furthermore, Bitstream also has an amazing surround sound experience.
On the other hand, PCM is used when you want to use secondary audio formats. If you want set up a system that supports secondary audio, chose PCM otherwise you can go for bitstream as they allow you to enjoy the benefits of audio codecs.