 Although you can say that network audio players, aka streamers, simply get audio files from a storage medium and send it to a digital drain log converter, there are many ways to do that. And almost all those systems are not compatible. In this 40 minutes long video, a comprehensive overview of most systems. The past 20 years playing media over networks has developed from extremely rudimentary to rather sophisticated. From a situation where 640 x 480 interlaced video and mp3 at 128 kilobits per second was just doable over a local network to a current reality where 4K video and 192 kHz 24 bit flag files are streamed over the internet. Even voice control is slowly getting into the market. In this video I will describe most popular network audio players, so no video. I will also demo Google Home, so if you have a Google Home speaker nearby, you might want to switch off its microphone during this presentation. Every digital audio player can be divided into a number of function blocks. Let's begin with storage. This is where the audio files are stored. These audio files will have some kind of labeling. In a CD player a CD has very rudimentary labeling, while in an advanced digital audio player this file might include over 100 metadata fields. A second building block I named control and the third database. We'll see their functions further on. A fourth function I named renderer. The fifth remote control. Please do realize that throughout this presentation these blocks represent functions, not necessarily physical devices. Storage can be a CD drive holding a CD, a hard disk, thumb drive or any other storage medium. Remote control can be an infrared remote like that of your TV but it can also be a smartphone, tablet or computer. Renderer in essence includes the digital to analog conversion, amplification and loudspeakers or headphones. Although in many cases amplification and loudspeakers and even sometimes digital to analog conversion will happen outside of the player. For this presentation however it is irrelevant whether these are integrated or done by separate devices. When the digital player is switched on it usually will query the storage for its content. The result will be stored in the database. When the user makes a request, control will check the database, gets the corresponding file from the storage and send it to the renderer. The user request can be done on the player or over a remote control. Simple infrared remote controls are unidirectional. More advanced remote controls like apps on a smartphone or tablet are bidirectional. If we remove the bidirectionality of the remote control we have the functionality of the first digital consumer player, the CD player. Now let's go to the present. Hey Google, play blues music over home speaker. Sure, here's the Spotify playlist called Blues Classics. Hey Google, stop. I am told that a subscription to Google Music would give more control but this is what early adapters are using now. And it's not only music files, you can also have it play radio stations. Hey Google, play BBC Radio 1. All right, here's BBC Radio 1 on the BBC. Hey Google, stop. I've shown you how the Google home speaker can play music but it can even route music to other players like the Chromecast Audio, Chromecast Video and Sonos products. Again subscriptions are needed for many functions but it can be done. Hey Google, play blues music over Chromecast Audio. Sure, playing your Spotify playlist called Blues Classics on Chromecast Audio. Hey Google, stop. Google is not the only voice controlled service. Apple and Amazon also have these kinds of services, although Apple has a rather close system and a less perfect system than Google. I have no hands-on experience with Amazon Echo yet. Now what's the topology of such a system? There are two environments, the cloud and home. The cloud does the control, the storage and the database and connects to their home environment over the network interface using the internet. At home there again is a network interface talking to control. Control listens to the internal microphones all the time to pick up the attention call hey Google and listens to the request. It sends that audio over the network to control in the cloud. There the instruction is interpreted and the response is returned to home. That can be a remark, a question or a result like playing music. I know of no home audio equipment that listens to any voice control system, not even if a service like if this then that is used for interfacing. IFTTT.com lets you specify what should be done on a given request. You can for instance define the request watch movie as light slow, blinds down, beamer on and AV receiver on Blu-ray player. But it requires some logic thinking and my guess is that it will take still some time before we see that widely used. Especially in the quality home audio market. Using file based audio players took over 15 years before it became more or less mainstream. Let's go back to that point in time for as often things are more clear when knowing how they developed over time. For at least two decades CD was the only way of playing digitized music. The music industry pushed the market to consume more and more music and found easy prospects in youngsters. The rate at which new hits were born and the financial limitations of the youth had already led to a lot of mixtapes on compact cassette. But the sound quality of affordable gear was very low while, even more important, the ruggedness of the cassette was poor and cassettes also laid a burden on the pocket money. By the time that bought a new computer and donated his old computer to the kids, a very comfortable way of proletarian sharing of music was discovered in the shape of mp3s. Just hook up two PC speakers to the computer and set up a sharing sneaker network with friends and now everyone can play the music that they shared. Later on the sneaker network was replaced by the internet. mp3s were ideal since they were about 10% of the data. Hard disk capacity was expensive at that time and sharing over the internet was slow. When we look at the block diagram of such a setup we see control, storage, database and renderer. Control being the sum of the operating system and the music player software, storage being the hard disk and the renderer being the software mixer of the operating system and the internal digital to analog conversion. The software mixer might have changed the level and even the sampling rate, depending on the PC settings. But no one cared, sound quality was less of an item for those youngsters since low quality audio was all they could afford anyway. A number of dads found this way of playing music a good idea so the laptop's headphone output was connected to the stereo and the living. Of course the headphone amp in the laptop was limited in audio quality and over time digital audio output started appearing on computers and laptops. Now a quality digital to analog converter could be used with the goal of improving the sound quality, although the software mixer still processes the sound. Furthermore, a computer has many internal clocks and other dirty signals like cheap switch mode power supplies that all interfere with each other. As a result, the spirit of signal suffered from the digital signal processing and the biggest enemy of digital audio, jitter. Although I expect jitter to be known by most of you, I will do a short recap. Let's imagine a short piece of analog music signal by chance being in a straight line like this. On digitizing, amplitude samples are taken at the given sampling frequency, like 44.1 kHz for CD. These measurements are stored in a table and sent to a transport or storage medium. On playback, the table is read and then rendered in discrete voltages. This would have resulted in a staircase pattern if not for the reconstruction filter that slows down the signal so that, at least in theory, the original straight line is regained. If the intervals at which the voltages are plotted are not very constant, there will be amplitude errors as can be clearly seen when a white line is plotted behind the resulting red line. This creates side bends at the modulation frequency of the clock and can lead to several sound quality problems, for instance degraded lows, distorted stereo image, poor focus within the stereo image and harshness in the midrange. It might be clear that connecting digital to analog converting to a PC is not a way to go if sound quality is important to you. Unless you prepare that PC in such a way that it produces a clean digital signal. This kind of PC is available commercially too and is called Music Server. Due to the special measures, relatively small production series and different distribution models, these are clearly more expensive than regular PCs. In the meantime, digital to analog converters with USB inputs came to the market. Initially it was what is known as USB Audio Class 1, an isochronous data stream, like SPDIF and thus with the same problem. The computer audio clock is master. And it's not the best master. USB Audio Class 1 is limited to two channel 96 kHz. Later on USB Audio Class 2 was developed. This is an asynchronous data transport where the digital to analog converter is master. It resulted in an improved sound quality and offers higher sampling rates, even up to 768 kHz 32 bits. As where USB Audio Class 1 is supported by all modern operating systems, USB Audio Class 2 has not been supported by Microsoft for a long time. A driver had to be installed to solve that. All other modern operating systems, Apple OS, Linux, Android, iOS and iPad OS have supported USB Audio Class 2 for years now and only recently Microsoft has added it to Windows 10. Large consumer electronics brands realize that videos, photos and music stored on the computer should be played in the living room too. This led to two standards that enabled playback of media from the computer in, for instance, the study over the network to a network player in the living room. DLNA is settled by brands like Sony, Films, Microsoft, ULT-Packet and others and initially had measures incorporated to prevent pirated software to be played. It did not recognize MP3s as audio files for instance. As far as I can see, DLNA is just a layer over the Universal Plug and Play AV standard. UP&P AV for short and in practice they appear to be interchangeable now the DLNA Anti-Piracy measures appear to be abandoned. So I will treat them as one standard. The system is supported by all major consumer electronics brands and many smaller high-end brands like Lin, Neym, Marans, Denon, Cambridge Audio and others. Some of these brands, like Lin and Yamaha, have made extensions to the DLNA standard for improved user experience. It has the advantage that all media on your computer can be played back on DLNA UP&P AV renderers like smart TVs, networked video players and networked audio players. Using clients like the video player VLC, you can also play this content over iPhones and iPads. It is clear, however, that video had the most attention. The usually large number of audio and photo files were, at least for a long time, handled slowly. Furthermore, only a limited number of metadata types for music were supported by the server programs. For the average pop and rock fan that only searches music on artist's name or track name, this posed no problem. Lovers of classical music like to search on conductor or composer and these fields were not supported. Jazz lovers want a look for combination of artists to find their favorite albums. Today there are server music programs specially aimed at music that handle all the 100 plus data fields modern metadata taggers offer. A very popular UP&P AV server program for audio is MinimServer. Another shortcoming of the UP&P AV and DLNA protocol is the lack of standard support for gapless playback of albums where the music of one track continues without interruption into the following track. Sargent Pepper Lonely Hearts Club banned by the Beatles is a good example, as are live albums. Today most network players that use DLNA or UP&P AV have solutions for this in the hardware. To recap, DLNA and UP&P AV have broad industry acceptance. Audio, video and photo is supported. A server program has to be running on a computer or NAS in the network. Designed primarily for video and therefore many server programs have limited metadata support. Playback of gapless albums is not supported and has to be solved in the player. When we look at the function diagram we find two environments. First the computer that has storage in the shape of a hard disk, controlled by OS and DLNA UP&P AV server with database and network. And second the network player that also has a network function that can either be Ethernet or Wi-Fi. Then control which is relatively simple firmware and renderer. The UP&P AV DLNA profile also knows a two-way remote control standard. Some years ago there were dedicated remote controls, nowadays smartphones and tablets are used. It comprises network, control and display. Control receives info from the control in the computer over the network, sends it to the display and returns touch info that the local control sends to control in the computer over the network. Control in the computer then sends the audio file to the network player. This setup can be controlled from all three environments, computer, remote control and network player. The most recent instruction is leading. You can control all network players from one remote but multi-room playback where players in different rooms can play in perfect sync is not supported. Several manufacturers have added their propriety extension for this. The list of brands that use DLNA is endless. Here are some popular brands that are licensees for a complete list CDDLNA.org site. UP&P AV has no certification program as far as I know but is part of the UP&P standard and I currently know of little cross-brand problems. DLNA initially was not picked up by music lovers, probably because the network players combined video and audio playback on one device. Especially in affordable equipment, the video electronics has a profound effect on the jitter behavior of the analog electronics. Furthermore, as mentioned, it was poor in browsing speed and had limited metadata support. When Slim Devices introduced the Slim 3 audio player, it wasn't a success either since it also had very poor jitter behavior. But they took the problem seriously and introduced the squeeze box only two years later. That was rapidly picked up by high-fi enthusiasts and although the jitter is not up to current standards, it was a lot better than its predecessor and the DLNA players. It also added internet services like Pandora, Napster, Lastfm and Sirius using an online service called MySqueezeBox.com. After three years they were brought by Logitech that after only six years ended the production but promised to keep maintaining MySqueezeBox.com and the local server program Logitech Media Server, LMS for short, which they did and still do. Today many people use Raspberry Pi small board computers with a sound card and shareware to emulate squeeze box functionality. When we look at the function diagram we see in essence the same setup as with UPnPAV. There is a computer with storage, control, database and network but now the DLNA UPnPAV server is replaced by the Logitech Media server program. And also on a network player side things look identical. Most squeeze box models had a display except for the Jewette that had a dedicated handheld remote control with iPod-like controls. A squeeze box system can be controlled from the player, from a remote control and from the computer. On the computer you use an HTML interface while on tablets and smartphones apps too are available from third parties. The system is not difficult to set up if you are familiar with computer technology but Digi-Phobes will have a hard time to get it playing. So if we sum it up we see that the software is still maintained but not further developed. It is partly open source and a lot of plugins are available, for instance for Spotify, Tidal and other streaming services. And the Logitech Media server also supports photo and video over UPnPAV. While combining video and serious audio in one player often leads to disappointing sound quality, combining both in a server program is no problem at all. When Sonos was introduced I wrote in my review of the Sonos Connect Network player that even my mother could install it. You don't know my late mother but believe me that's a statement. However, that's not all that made Sonos popular. The installation was easy since on the computer you only had to share the folder that holds the music files. The Sonos player then starts reading the metadata from the share and builds a database in the player itself, making browsing and searching music a lot faster. Initially, it had to be used with a proprietary remote control, again with an iPod-like user interface. Later on an iPod touch-like remote was introduced but it costed more than a real iPod touch and worked less perfect than the app on the touch. Yet another clever technique was added. It uses a mesh network for connection with other Sonos players which was, with the WiFi standards of that time, clearly a bonus. One player is master and is connected to your home network and if you have more than one player, the other players connect to each other over a proprietary WiFi-like mesh network that connects each player with every other player within reach. If you don't have a network connection close by one of the players, there even is a bridge that connects your network to the Sonos mesh network. The system is enormously robust and their program not only had the network streamer shown here but also one with power amplifiers integrated, plus several active speakers that only needed a power outlet to play. Recently Sonos introduced a new operating system that, although it is backwards compatible, does not offer new features when used with older hardware. Despite rumors, Sonos equipment will only play music files at CD resolution, high-res music is not supported. When we look at the function diagram, we see that the computer or NES only has to share the volume that holds the music to the network. Control in the Sonos network player, being a player that has to be connected to your stereo or active speakers, will access the share, index it and store it in the internal database. This index is then shared with other Sonos players in a mesh network. Sonos players have, next to no controls, only some models have volume controls. You will need to use a smartphone or tablet as controller. To recap, installation is easy, it offers faster browsing, quick searching and uses a mesh network. Since there is a very large install base about any internet music streaming service love to work with Sonos. There are limitations too. The internal memory limits, at least in theory the number of tracks that can be indexed. The exact number depends on the amount of metadata and the size of the cover art. Sonos mentions a maximum of 64,000 tracks, which will be around 6,500 albums. Furthermore, it is a close system with the advantage of operational reliability and the disadvantage of having to deal with the choices of Sonos. Last but not least, the sound quality is aimed at the average consumer, not at audio files. Apple had the same idea about sharing audio, video and photos and set up their own environment, including an online music shop. Although Steve Jobs reportedly owned a very high-end audio system, Apple started off with selling 128 kilobits per second AAC-coded music that included copyright protection. After a few years that changed to 256 kilobits AAC and the copyright protection was abandoned. iTunes initially was only available for Apple computers and was used to load music onto the iPod music player. Their airport Wi-Fi access points got optical digital outputs that iTunes could stream music to in lossless PCM up to 48 kHz sampling. The output signal was quite jittery. Later on Apple TVs came to market, effectively video and photo streamers that also could stream music from iTunes. Apple made a clever move by licensing manufacturers for AirPlay, a streaming protocol that uses encryption and lossless compression for the transport over the network. Many brands offered AirPlay streaming, often next to other systems like DNLA. To do a roundup, it's easy to set up for Apple computer users. The Windows version is known to be less robust. iTunes has good ripping facilities with metadata completion integrated and uses a robust streaming protocol that is licensed to many manufacturers of playback hardware. It's a close system and thus operates reliable but allows no streaming from other streaming companies and is limited to a maximum of 48 kHz sampling. Only a few years later, a couple of computer buffs being dissatisfied with music software players on computers developed a very sophisticated music player that physically looked like an ordering computer system found in restaurants. It was amongst the best user interfaces while it automatically completes metadata, artist bio, album reviews and album art. A complete system was offered including an automatic backup system for the music files and database. A basic system could easily set you back 12,000 USD or more. The founders had less experience building good sounding hardware, which was a problem for a system of this price. After four years they were bought by high-end audio specialist Meridian that brought the audio quality up to standard. The Meridian Sulus Control is a fully integrated system that not only holds a hard disk but also a CD drive to automatically rip the music from the CD to the hard disk. It uses a touchscreen to access the music through the extensive metadata it collected itself from metadata services on the internet. The user interface is brilliant and after the Meridian upgrade it sounds fantastic. The initially rather high price had come down drastically but in 2019 Meridian announced to freeze development of the system. The metadata service remains active however. When we look at the function diagram we see the usual functions Control, storage and database but this time there is a touchscreen as user interface and a CD drive for ripping. Then of course rendering and network complete the setup. After startup Control checks the storage for content. Further content can be added using the CD drive. The system collects metadata from internet services and the result is stored in the database. After receiving instructions from the touchscreen, Control checks the database gets the associated file or files from storage and send them to renderer. A remote control in the shape of a smartphone or tablet can be used too. Music stored on a shared volume on either a computer or NAS can be indexed and played as well. It can even have the metadata updated without changing anything to the audio files since all metadata is stored in the database, not in the audio files. Lembrook, the mother company of Audio Brand NAD, must have seen the gap between Sonos and the Sudo's like products and introduced the Blue Sound brand in 2014, 12 years after the introduction of Sonos. It basically uses the same approach. Easy installation, self-indexing and smartphone or tablet as remote. But there are also clear differences. Blue Sound products have primary controls like volume, play ports, forward and back. Most current products also have five pre-select buttons that let you start favorite radio stations, playlists or albums. Furthermore it can also play from a USB drive connected to the player directly. This way no computer or NAS has to be switched on to play music. A mesh network is not used. Most homes nowadays have fast Wi-Fi throughout the house. There even is a product with a hard disk and CD drives that will rip your CD collection and add metadata to the audio files. After the MQA audio format was introduced, all Blue Sound players were updated to be an MQA decoder and renderer. Which brings us to the sound quality that is clearly higher than that of the Sonos products. The function diagram is much like that of Sonos. The computer or NAS only has to share a volume containing the music to the network and if you use a USB drive connected directly, the computer isn't even needed. The network player indexes the music content on the share or on the USB drive and stores that in the database on the player. Blue Sound states that up to 200,000 tracks can be indexed depending on the amount of metadata and the size of the cover art. That's about 15,000 albums. The renderer is MQA enabled and a smartphone tablet or computer is used as remote control. Most popular streaming services are supported too. After a few years the NAD brand introduced products with Blue Sound streaming integrated. There are amplifiers, AV receivers and network players that work with the Blue Sound protocol and do include MQA decoding and rendering. This way the Blue Sound system got access to a market of even higher sound quality. As we have seen earlier, you can have the computer take care of the music playback. But without special care the computer will route the music bits over the internal DSP function like the samperate converter and volume control. We also have seen that using the internal DAC isn't going to offer serious sound quality due to a very high jittery clock signal. Connecting an external DAC over USB audio class 2 makes the sound independent of the computer's clock and can yield better results, if the DSP function of the PC is bypassed. When you use programs that provide so called bit perfect signals, that is taken care of automatically on Max and Linux and might take special care on Windows computers depending on the version you use. The software will have clear instructions on how to handle that. Still the galvanic connection, the USB cable, will cause deterioration of the sound quality for reason I will describe later. A very good solution then is the network bridge. Basically it's a simple device optimized for music reproduction where programs can send music to. It's the same as a basic DLNA UP and PAV player or a squeeze box but then controlled over an audiophile music player on a computer. Often network bridges can function as DLNA UP and PAV renderer or squeeze box. And music player programs like Audivana 2 Plus and J River Media Center can send bit perfect music to a network bridge using the DLNA UP and PAV protocol. To recap, easy physical installation but requires special software for bit perfect playback. Multiple clocks in PCs interfere with the audio clock resulting in jitter. Furthermore the fan noise and the hardest noise is not wanted in the listening room while the electronic noise will pollute the DAC. A good solution for this is a network bridge that effectively functions as a USB audio class 2 connection at a distance, connected to the PC over the network. This makes that the computer can be placed elsewhere in the house. The network bridge produces far less electronic noise than a normal PC and therefore will degrade the music far less. I'll get back to this later on. This is another software player that works this way and has become enormously popular. When Sulus was bought by Meridian, the Sulus founders developed the system further as employees of Meridian but over time it appeared that the vision they had could not be realised within the Meridian organization. In 2016 they left Meridian a founded RuneLabs. Their vision was to make the best music player program that would deliver bit perfect music to devices of as many brands as possible. The user interface was based on Sulus but further perfected. Metadata, ArtistBO and Album reviews are still added. Instead of running on dedicated hardware as with Sulus it runs on a normal computer on the Windows, MacOS or Linux as long as it complies to some hardware specifications, like a Core i3 level processor or higher and a separate SSD system drive. There also is a special server version of Rune that runs on a headless Intel Knock computer. Once installed it needs no further user maintenance and updates can be taken care of automatically. Playback can be done as normal with computers over the internal digital to analog conversion or using an external DAC. They also developed a protocol to send audio over the network to what they call an endpoint. In its basic form it's just a network bridge that is connected to the computer over a network connection using a special protocol called RAD. In almost five years of existence they managed to have many brands support this protocol that is user maintenance free. Over 800 devices by over 220 manufacturers are now available. Those include brands like Blue Sound, NAD, Aurelique, Volumio and others that support RAD next to their own protocol. It supports a multi-room and allows for plugins called extensions. Next to the RAD protocol Rune can also stream to Sonos, Chromecast and Airplay devices, of course with the hardware limitation of 48 kHz. Despite the price that is higher than that of other music software players, it is very popular amongst music lovers and high-end audio fans. One reason might be that it works flawlessly with equipment like a Raspberry Pi with sound card running RAD software, with streamers costing tens of thousands of euros and anything in between. A Blue Sound speaker in the study, a Sonos waterproof ceiling speaker in the bathroom, the old MIDI stereo with Chromecast streamer in the kitchen, the PC speakers in the study and the Aurelique RSG to network player as RAD endpoint in the high-end audio system in the living, all controllable from your smartphone, tablet or computer. It integrates your music collection completely with your pick of music in Tidal and Cobas streaming services. I often don't know whether I am streaming from either Tidal or Cobas or from my own music collection. But this all comes at a price. A yearly subscription costs 120 dollars, a lifetime subscription 700 dollars. But if you have a subscription on Tidal or Cobas, they see one Roon server as one client while it can serve all your endpoints with different music in different rooms at the same time. So there are closed systems linked to a hardware manufacturer, there are generic systems supported by many brands but there are also systems that are often added as a second system like Apple Airplay on DnL-A streamers or Roon Endpoint on a Blue Sound streamer. Recently I have seen Chromecast Audio added to streamers. Bluetooth is also supported on many devices but this is a lossy system using only 20% of the bits and dust thrown away information. You could also use a normal household computer for music reproduction but if you are only slightly critical on the sound quality, you might be tempted to add all kinds of quality-improving measures like a linear power supply for the computer, a USB signal cleaner or a i2 SPCI card with separate audio grade power supply. Binder done it and they all help a bit but in the end you have spent more on those accessories than a better sounding network bridge would have cost. But that's less adventurous and the money has to be spent at one instance where with those gadgets you get a few happy buying moments more. Believe it or not, I'm not even being cynical. I know how it is to go that route. That's where I got a part of my experience from. And with that bombshell we came to the end of this video. I hope you enjoyed it, if so, it's good to know that there will be another video next Friday as always at 5pm central european time. If you don't want to miss that, subscribe to my channel or follow me on the social media so you will be informed when new videos are out. If you liked this video, give it a thumbs up. Many thanks to all that supports this channel financially, it keeps me independent and thus trustworthy. If you also feel like supporting my work, the links are in the comments below this video on youtube. I'm Hans Beekhuyzen, thank you for watching and see you in the next show or on theHBproject.com. And whatever you do, enjoy the music.