PCM vs bitstream – which audio decoding has better sound?

Are you a home theater fan? Or do you prefer watching movies at home instead of in the cinema? If so, you’re probably looking for the best way to enhance your viewing experience? And then you bumped into a dilemma: PCM vs Bitstream. 

Which one to choose for perfecting the sound of your favorite movie? A two-channel system or a surround sound?

Find out the differences between these two sound systems, the advantages and disadvantages, prices, in which situations is better to use PCM, and when is Bitstream a better choice. This article will provide you with the answers you’re looking for.

Bitstream Surround Sound System
Bitstream Surround Sound System
PCM 2.1
PCM 2.1

PCM vs Bitstream – Why is it a tough choice?

Visual and sound impressions are two sides of one coin. And even people who claim not to pay too much attention to sound while watching a movie are not immune to how it affects us. 

Do you know why sound is so essential in the viewing experience? Because human beings are complex. While video triggers our intellectual process, the sound works more profoundly and triggers our emotions. 

For a fulfilling experience, we need both. But the answer to which system can provide better sound might not be so straightforward – it depends. 

Yes, we know. Not the answer you expected, but there are too many factors that impact the overall impression that it is impossible to claim that one is better than the other before checking all the aspects.

So, let’s go through all the points and situations that might impact your decision regarding PCM vs Bitstream. And we’ll begin by explaining these two audio systems. 

We’ll start with pulse-code modulation (PCM). Why? Because it was the first one used. 

What is PCM?

PCM, or pulse code modulation, was initially referred to as analog audio conversion to digital. But today, it means your TV processor will convert the digital signal into a specific format adjusted to two speakers and a subwoofer.

Yes, PCM was introduced in 1937 by the English inventor Alec H. Reeves, who thought that the best solution for eliminating noise in long-distance telephony was using purely electronic digital techniques. He patented his idea in France in 1938 and the following year in the USA. 

Unfortunately, he couldn’t implement the solution due to the state of electronics back then, and even Reeves figured out that the PCM was an idea ahead of its time and walked away from it.

In fact, PCM wasn’t implemented until 1943, when Bell Telephone Laboratories (today, Nokia Bell Labs) used PCM binary coding for the SIGSALY system. Now, SIGSALY had a totally different mission. It was created to make phone calls a secret. 

The project SIGSALY was the solution that Bell Telephone Laboratories provided to the U.S. Army for a new way of securing voice communications. 

Since the whole project was a secret, the SIGSALY was not presented to the world until WWII was over. 

Now, you might think that all televisions made after WWII were using PCM. No, that’s not the case. Though it seemed easy, implementing PCM wide-used civilian technology was not without its challenges. It wasn’t used for TVs until the 1970s when digital audio processors came out.

How does PCM work? 

It primarily transforms analog into a digital signal (pulse), samples it, codes it, and transmits it in an analog form. It is the standard form used for digital audio in computers, compact discs, Blu-ray, digital telephony, and similar applications.

What does the PCM setting on your TV mean?

It means that your TV audio processor will process the digital audio signal, convert it to 2.0 or 2.1 formats (two speakers and a subwoofer), and send the audio to the TV’s speakers or TV’s audio outputs.

The PCM setting enables the TV to receive the audio signal from Blu-ray players, game consoles, or set-top boxes and send the audio signal to output devices such as speakers, soundbars, and headphones

We could say that this format is universal since most devices have two speakers, but if you use some advanced acoustics, the sound might be lower quality than expected. It will lower the format to adjust it to two speakers and, therefore, lower the sound quality.  

When is best to use PCM?

It’s best to use this option if:

  1. You do not have an AV receiver and output the sound via the TV’s speakers.
  2. You want to output HD sound formats such as Dolby True HD or DTS HD, but the AV receiver does not support them.
  3. You want to connect the TV with a two-channel audio system. If selecting more than two speakers, the sound might be of lower quality.
  4. Your TV doesn’t support Dolby Digital or DTS; selecting PCM will improve the sound quality when connecting to a soundbar. 
  5. You want to hear secondary audio. You will not hear additional audio elements to the main soundtrack if you use Bitstream.

What is Bitstream?

Bitstream is a method that uses a binary system (1s and 0s) for transmitting sound or transferring information from one device to another. It is used in computers, networking, and audio devices.

This audio method was first introduced in 1987 by Philips. They presented a new data conversion technique that converts binary samples of an analog audio signal into a 1-bit code using oversampling, noise shaping, and pulse density modulation (PDM).

Bitstream represents an attempt to reduce bandwidth and storage requirements while retaining CD-quality sound, and it is the core technology used in home theater audio.

How does Bitstream work? 

Bitstream audio converts audio sound into digital bits; the information is transferred from the sound device to the receiver. The receiver decodes it and delivers it to you as a listener. 

It’s pretty much straightforward. And due to the compression, Bitstream can solve the problem if you need to store music or other audio and have limited storage. 

What does the Bitstream setting on your TV mean?

If you set the Bitstream option on your TV, it will just pass the information to your home theater receiver or a soundbar, where it will be encoded and displayed to you through the soundbar and speakers. 

It’s the perfect choice for home theaters, where you have more than two speakers.

When is best to use Bitstream?

It’s best to use Bitstream if:

  1. You use 5.1 surround sound 
  2. You’re using a receiver with a better audio processing power
  3. You want more flexibility in playing hi-res audio
  4. You have a high-quality receiver.
  5. If you have a home theater.

Side by Side Comparison

Let’s be honest, most people will not even notice the difference in the sound quality displayed through PCM vs Bitstream. However, for those with sensitive ears, the difference will be noticeable.

And we have to mention that sound quality is not the only thing that should be considered when choosing the PCM or Bitstream method. 

We’ve prepared a comparison list to help you decide which method you will use. 

FeaturesPCMBitstream
TransmissionWorks with players and receivers that support both analog and digital sound transmission. Works with players and receivers that support digital sound transmission.
Supported filesMost DVD and Blu-ray players can set audio output to PCM, meaning that your player will decode all the audio files, including Dolby Digital, Dolby TrueHD, DTS, and DTS HD Master Audio.  The bitstream transfer process includes Dolby Digital, EX, Plus, TrueHD, Atmos, DTS, DTS-ES, DTS 96/24, DTS HD-Master Audio, and DTS:X.
CompatibilityPCM is compatible with most available players, such as DVD and Blu-ray players or CD systems.Bitstream is compatible only with modern devices that support hi-res surround sound format. 
DecodingThe decoding process happens within the player.The decoding process happens within the receiver.
Secondary audioIt supports secondary audio and provides satisfying sound quality.Limited options when it comes to a secondary audio
ConnectionRequires a physical connection from the player to the AVR and speaker.It offers both wired and wireless systems.
PricePCM might be less expensive than Bitstream since it doesn’t require an AV receiver. Since the decoding is happening in the receiver, you need to consider an additional expense.

Bitstream vs PCM – Pros and Cons

If you look at the comparison of PCM vs Bitstream, you will notice that both systems have some limitations, which might become an obstacle or disadvantage. 

On the other hand, there are some useful things that might prevail on one side or the other.

PCM Pros and Cons

Without further ado, let’s check the pros and cons of the PCM system.

PCM Pros and Cons
PCM Pros and Cons
ProsCons
Uncompressed signal (no delays)
It works well with almost every device
No lag
Less work for the receiver
It’s direct and, therefore, quicker
It needs an HDMI cable to connect with input audio devices
The player determines the audio quality
Requires more work to be done by the player.

Bitstream Pros and Cons

Before choosing, check the pros and cons of Bitstream and compare the two systems, PCM vs Bitstream.

Bitstream Pros and Cons
Bitstream Pros and Cons
ProsCons
Both wired and wireless connections with input audio devices
Sends an encoded 5.1 signal
High-quality receivers can produce a high-quality sound
The broader specter of the decoding/transmitting file types.
Compresses signal (saves storage)
Works only for devices that support hi-res surround sound format
Supplemental audio is scaled down, which decreases quality.
More work is placed on the receiver.

Differences and Similarities

The main differences between the two are not related to the sound quality itself but more to the technicalities. 

  • Coding/decoding – With PCM, the player does all coding and decoding, while with Bitstream, it’s done by a receiver, 
  • Connectivity – While PCM can connect only through the optical cable, Bitstream offers both options, wired and wireless.
  • Transmission – While PCM works both with analog and digital, Bitstream works only with digital formats.

When it comes to similarities, you should know that:

  • Both systems can provide excellent sound quality.
  • Both methods work with digital formats.
  • Both support Dolby Digital, Dolby TrueHD, DTS, and DTS HD Master Audio.

Frequently Asked Questions

What player can I use for the best PCM sound experience?

There are many options on the market if you want to stay on a budget and still get the best sound quality, such as the 4K Sony Blu-Ray DVD Player, which scored 4.4 out of 5 stars from 1,870 Amazon users.

Should I set my TV to PCM or Bitstream?

If you use TV speakers only, then it might be better to use PCM, and if you use a surround sound system, Bitstream is the right choice.

Why the sound on my TV’s speakers is not synchronized with the picture via HDMI?

This issue might occur if the audio format of the HDMI device is connected to the TV that is set to bitstream output (such as Dolby Digital, Plus, DTS, etc.) and can be fixed if you switch the audio format of the HDMI device to PCM.

What is the most affordable option for a good-quality receiver for my home theater?

If you are searching for the most affordable AV receiver for your home theater, perhaps Sony STRDH590 5.2 Channel Surround Sound Home Theater Receiver could be the right choice. More than 3,300 Amazon users rated it with 4.5 out of 5 stars.

How can I change the audio mode on my TV?

When changing the audio mode, you need to consider both input (the device that sends signals) and output devices (the device that receives signals from your TV). When choosing the HDMI input audio in the TV’s setup menu, you’ll probably get PCM and Bitstream options. 

I have connected my soundbar to the TV, but there’s no sound. How to fix it?

If you are experiencing sound issues and you’ve recently connected the soundbar to your TV with HDMI, you might want to double-check whether you’ve done everything correctly.

Is PCM audio the best?

Hmm, Bitstream originated from PCM, as an advanced version, but nevertheless, the PCM sound is probably still irreplaceable when using less than 3 sound devices.

Conclusion

Yes, it’s a tough choice with PCM vs Bitstream, since the quality of the sound will largely depend on the devices and the file formats you use.

So, if you want to set a system for your home theater or any other surround sound system, you should probably go with Bitstream.

On the other hand, if you use only speakers on your TV, or if the secondary sounds are important to you, you might go with PCM.

Whatever you choose, don’t forget that you can always switch back if your first choice doesn’t sound too good, and don’t forget that the overall experience will largely depend on the equipment quality.

Oh, and one more tip. If you are changing your settings from PCM to Bitstream or vice versa on your TV or receiver, turn off/restart your TV/receiver and turn it on again to ensure the changes are implemented. 

Avatar of Jon
About Jon

Hey, I'm Jon. I'm an engineer by trade, so it makes sense that I'm obsessed with anything technology related! On the weekends, you can find me playing around with my computers or fixing something around the house. Feel free to leave a comment if you want to get in touch.

Leave a Comment

Previous

Dolby cinema vs imax – which cinema technology is better?

HDMI arc vs optical – which audio connection is better?

Next