Those of you who are moviegoers will know very well that the audiovisual experience that they show us in the cinema is completely weighed down at home because in the process the complex sound system is completely lost, which is an integral part of the composition of the films. . The best way? Set up the home theater, but with our PCs as the basis of a Home Cinema.
To enjoy the best home theater experience it is not necessary to use expensive hi-fi equipment, in theory what we can do is use our PC to perform this function, which means a huge money saving by not having to have both equipments in the same place.
A PC as the center of a Home Cinema?
Today with a large number of boxes with the ability to play content by streaming costing a portion of what a PC costs, it seems silly to opt for one as the center of a Home Cinema. If we look at it from the video part exclusively, a PC is the best, thanks to the advanced graphics cards and their advanced hardware codecs, the video quality in them is excellent.
However, there is a problem when it comes to mounting a contemporary Home Cinema and that is the fact that audio has been greatly neglected in recent years, leaving the PC out of date when it comes to dealing with multichannel audio systems. This has been given by the integration of what we call the sound card, where instead of DSP appearing more and more powerful, the market capable of decoding audio at higher quality, the world of the PC has become stagnant.
That greatly influences when setting up a PC-based Home Cinema. Below we explain the causes and how they influence when setting up our Home Cinema.
The audio quality problem
The evolution of multichannel sound in the last two decades has been impressive to say the least, but unfortunately within the consumer market it has gone almost unnoticed, whether we are talking about watching movies on television or when it comes to playing video games both on PC and on consoles. Despite the advances we still have many people listening to the audio of their movies and games on the simple stereo speakers of their television, with poor bandwidths and sound with less quality due to the compression of the audio data.
The sad thing, and this is not a subjective opinion, is that this occurs on PCs where most users continue to use the same audio output interfaces that existed in the 90s. It is due to the fact that the HDMI standard is not only a video but also audio transporter.
To understand the problem of bandwidth we have to understand that in a system of multiple speakers, what is sent are several simultaneous audio streams, one for each speaker. When you are listening to music on the street with your headphones at for example 256 Kbps bitrate, what you really do is listen to it at 128 Kbps per channel, it is true that through a DAC the digital data has been converted into analog signals up to reach your ear, but the base information is those 128 Kbps.
The problem, therefore, is in the data at source and is that although digital can replace analog audio, it needs a large amount of data to get closer and closer to the original source and with it a greater processing capacity, but we need powerful processors for this.
Multi-channel audio formats
In recent years, numerous multichannel formats have appeared, the most primitive of all is Dolby Digital or AC-3, which was released with the DVD output. This audio format was the most advanced in the late 90s and early 2000s and the vast majority of setups support it easily and more today since it does not require power, even a simple sound card integrated in the motherboard can support it.
Dolby Digital has a maximum bitrate of 448 Kbps on DVDs and 640 Kbps on Blu-Rays. Although if you decide to opt for a stereo system then the bitrate is a little better and goes to 192 Kbps. In any case it is an outdated system today. Its evolution was the Dolby Digital EX that adds an additional rear channel, 6.1, both virtually and created by a 5.1 system or by adding an additional speaker, but few systems use it.
Years later, with Blu-Ray already on the market and with the HDMI port as a universal audio and video transporter, we saw the appearance of Dolby Digital Plus or E-AC-3. It is a 6.1 and 7.1 format, but with 1.7 Mbps bitrates. Which has become the standard format for streaming content on media such as Amazon Prime, Netflix, Disney +, etc.
The icing on the cake came with the Dolby TrueHD with the ability to offer lossless multichannel sound, and then add the Dolby Atmos, which not only takes into account the position of the speakers horizontally, but also in height. Adding more audio sources and requiring not only more and more bandwidth to transmit data, but also greater processing capacity.
What happened to the sound cards?
Sound cards were not created to reproduce sound for cinema, but for music production actually. Being its use in games a collateral consequence of that. The problem? As we’ve said before, most people play with stereo speakers and settle for very low bit rates. A phenomenon similar to that which occurred in the world of music in which MP3s with their low bitrate became standardized. The reason? User convenience and the fact that for many AC-3 quality multi-channel audio even after 20 years is good enough.
There is a myth that sound cards have evolved over time for the decoding of multichannel audio systems. Reality? Its main task is not that and most of the designers of the audio DSP do not consume transistors in their design to decode the different multichannel audio formats. This is because the standard for PC audio stayed in 2004 and since then they have not sat down to improve it.
Most of the HTPC that are sold or assembled by people do not carry a sound card today due to the fact that it is completely useless when it comes to decoding the new standards. That is why AVRs or AV Receivers are used to decode the audio that comes from the HDMI port, either from the console, the Blu-ray player or the PC itself.
Windows 10 does not let go beyond 7.1
Since we are talking about limitations, it must be taken into account that Windows 10 does not allow transmitting beyond a 7.1 configuration in LPCM audio format . If this seems contradictory to you, just remember that the format in which the data is sent in Dolby systems is PCM, with LPCM being one of its variations.
Of course, you can buy the driver for Dolby Atmos in Windows 10, but it must be remembered that this format requires the use of the HDMI port on the graphics card. And yes, it would be great if our powerful GPUs could decode the most advanced multichannel audio formats without problems and believe us they have the power to do so. Instead what they do is send the audio in stereo to the monitor or TV, which is disappointing.
This means that we need today not a sound card but an AV receiver. Of course, the audio in some applications is managed alone, but 90% of them use the standard Windows audio libraries on PC, with the limitations that this implies. In any case, we recommend you buy the drivers for Dolby Atmos even if you are not going to use it in all its splendor, the improvement in sound quality makes it worth it.
AV Receiver for Home Cinema on PC?
In all conventional Home Cinema there is a central element that is the AV receiver, from which the rest of its components are oriented. One might think that with the powerful PCs we have we can save the AV receiver and distribute the signal to the different speakers and yes, it is true in old formats, so in that case you do not need an AVR at all, but If you want something that is a Home Cinema with a face and eyes on a PC, unfortunately you have to go to the box and buy an AVR Receiver
What is your job? Well, receive the audio and video signals from the different sources and adapt them in real time so that they sound in the best way in the speaker system that we have installed, as well as process it so that it can be used with a surround sound system such as DTS, Dolby Digital, Atmos, etc.
To this day, it takes the HDMI signal, so it also takes the video signal and therefore we not only have to make sure that it can decode the audio formats, but that the HDMI output of the AV receiver itself does not degrade the quality. image from the original video source. There is nothing worse than a 4K HDR television receiving signals in Full HD SDR format just because the AV receiver does not have enough power.
Which AV receiver to choose?
In the market there are a large number of AV receivers and of various prices, the first thing you have to take into account is the situation of your living room and what configuration you are going to use. Not because you use a format that supports 7.1 you have to have 7 speakers and a subwoofer, but you can use a much smaller and simpler configuration.
What reasons do we have to buy an AV receiver? Well the following:
- You can connect different devices to it, so you can output multi-channel audio from your consoles, video players, smart devices, etc.
- It has the ability to amplify sound.
- Many of them have multiple video outputs, so you can mount a projector and send the signal through it as well.
- Unlike other all-in-one systems, you can replace your AV receiver in the future and keep the speakers and vice versa.
- You can choose to connect any speaker configuration, you are not limited to just one.
When choosing an AV receiver you have to take into account two very important elements and that have to do with the speakers that you are going to install later, these are the amount of watts that your speakers can reproduce and, on the other hand, the impedance. This is the first discard on the list that you have to make.
The other is the connections, there are AV receivers on the market with a large number of connections, some of them make sense if you have a 5.1 or 7.1 card. Which does not decode the audio in more advanced formats. If your audio is going to be output through the HDMI output, you will not need them as input ports for your AV receiver.
The problem with audio extractors
An audio extractor is a small box that takes the HDMI signal and separates the audio carrier from the video. The problem? The audio is normally transmitted to optical output and not HDMI, so if you want to mount a powerful Home Cinema you will not be able to do so. Of course, you can connect an integrated 5.1 speaker system or even use other solutions such as the Amazon Echo. The problem? This degrades sound quality and many of these systems do not actually decode, but remove information in the process.
If you think a simple 5.1 like the ones from twenty years ago is good enough for you then go ahead, it’s a good choice. But it is only the toy version compared to a Home Cinema with a face and eyes.
Home Cinema speakers for our PC
In traditional Home Cinema the following types of speakers are usually sold:
- Shelf-monitor speakers: they are smaller in size, these have two outputs through which the sound comes out. One for the bass and the other for the treble. Although they require a subwoofer to reproduce they are ideal for living rooms that are smaller than the bookshelf-floor.
- Bookshelf-floor speakers: These are usually much larger than bookshelf-monitor speakers, as they can have more than 3 or more channels and include a larger soundboard. This allows them to reproduce bass sounds better, so unlike bookshelf-monitor speakers they do not require a subwoofer to compensate, but require much larger rooms.
The first speakers that we must acquire are the two front speakers and the central one, these are the ones that will reproduce most of the sound that we will hear in movies and games. Not surprisingly, between 70 and 80% of the sound you hear you will hear in those two speakers and the change to a higher quality one is already noticeable. The work of the central? Play dialogues from movies and games. The best choice? Buy the front and center speakers in a complete kit and that they are compatible with each other, that is, with the same technical specifications, and then buy the rest of the speaker system.
Can I use a PC speaker in an AV receiver? Power can be done, but as we have said before you have to take into account the power and impedance of the speakers when choosing the AV receiver and we honestly do not recommend them if you are going to use an AV receiver.
