Up to 37% in savings when you subscribe to hi-fi+
hifi-logo-footer

Begin typing your search above and press return to search. Press Esc to cancel.

Introduction to streaming

Introduction to streaming

Streaming is not a new format, nor even new technology, but it has taken the place of the CD in many enthusiasts systems, so has the characteristics of a format in our world. In fact its strength is that its almost format free. In theory and often in practice as well you can stream existing audio formats on a piece of hardware that can also accommodate future formats. This may require a hardware update but often a software update over the web is sufficient, it is tremendously flexible in that respect.

But why has streaming proved so popular? There are number of reasons prime among them being the ease of access to your music collection. We no longer wear hair shirts and expect to fine tune the LP12 every time we sit down for a session (praise the lord), we want easy access and good sound. And there’s nothing quite as easy as selecting your music on a tablet computer from the listening seat. That’s not to say that sound quality is secondary however, a good streaming source is extremely resolute and engaging. The majority of streamers sound more refined than the majority of CD players, pound for pound they are a revelation in this respect. If the harsh glare of digital audio has kept you in the analogue fold you might be pleasantly surprised by the presentation of a decent streamer. Pitting the best streamers against the best CDPs will split opinion of course, but in my experience streamers excel at low level detail, refinement and openness while disc spinners have the upper hand at timing and the emotional engagement that good timing delivers. The fact that Naim uses its NDS streamer to demonstrate the megabucks Statement amplifiers rather than the more costly CD555 CD player should tell you something. It’s clear from sales data that CD players are being squeezed out by the revival of turntables and the ascent of streamers.

, Introduction to streaming

The other obvious advantage they have in the digital arena is the ability to playback higher bit and sample rate recordings, unlike CD players streamers are not restricted to the 16‑bit/44.1kHz red book format. Chipsets exist that can replay sample rates up to 384kHz and quadruple DSD (DSD256), and quite possibly higher by the time you read this. Higher bit and sample rates are not in themselves a panacea for good sound of course, you can probably remember numbers races in the past such as THD where better figures did not mean better sound. I heard recently that the BBC used to send FM signals to its transmitters at 13‑bit in the seventies, and FM was considered pretty good back then. Today’s DAB broadcasts stretch to 128kbps if you’re lucky.

History

Streaming started in what is now called the CI or custom installation world back in the nineties, when you want to send audio to multiple rooms and control it from a single point you can ‘t beat transmitting through a network. The CI industry used computer platforms and storage systems to develop means of providing multiroom audio without multiple sources, and companies including Naim and Linn started out in streaming this way. Both have now abandoned CI and concentrate on domestic streaming hardware, Linn doing so in the most dramatic fashion when it announced that it would stop making CD players in late 2009.

, Introduction to streaming

The more affordable entry point in the early days was Squeezebox’s range of rendering devices or players. Squeezebox released a full size streamer called the Transporter but it was the smaller and rather more affordable Touch that captured the attention of enthusiasts. The brand itself has been absorbed into the Logitech fold and this hardware is no longer around but the Touch remains a popular player with numerous mods and tweaks available to the enthusiast, you can even get it to stream the latest music services.

 

Computing

The computer has always been the basis of digital audio streaming, the least expensive way to dip a toe is to connect a laptop to a DAC via a length of USB cable. This approach is dubbed the ‘push’ approach because the computer sends the signal to the converter, a streamer on the other hand ‘pulls’ the data from the source, usually a NAS drive. Using a computer has the advantage of flexibility in the choice of playback software and cost but to get decent sound quality you need a dedicated computer that has been built with this purpose in mind, which tends to undermine the cheapness factor. In most instances you need direct access to the computer to control playback but software such as JRiver Media Center can be controlled with an app on a tablet. The only other limitation is that USB leads do not perform quite so well if they are over a metre or two long.

A streamer or renderer on the other hand is built from the ground up as an audio component, therefore attention is paid to keeping out RFI through the use of linear power supplies and minimising jitter and the other ills of digital audio that the computer world is not bothered about. Streamers connect to the network where they can pull audio data from a media server, generally a network attached hard drive or NAS with an operating system such as Twonky media onboard. Companies including Naim and more recently Melco offer higher quality servers that can also rip CDs and offer alternative connections alongside the RJ45 socket required for connection to a network wired with Ethernet cable. For best results and high resolution formats a network should be wired rather than wireless, but as Sonos has proved wireless networks are good enough for many.

, Introduction to streaming

Another school of thought is to have the music stored on the player itself, eliminating the need for separate music storage, this is what happens in a Naim HDX and a variety of both high and budget end products. It simplifies initial set up at the cost of flexibility. But it does mean that the network is only necessary for control and grabbing metadata so can be wireless without sonic compromise.

Networking

The network approach means that the media server or storage device need not be in the same room as the player, and as NAS drives are not the quietest things this is quite handy. It also means that multiple players can share the same drive, both wired and wirelessly. One of the nice things about having your music on a network is that any streaming device can access it, in my case that means the iPod Touch that plugs into the kitchen radio, but it could just as easily be a smartphone. And while you need a tablet or smartphone to use the control app for a dedicated streamer, that same handheld device can be both controller and player. Therein lies the rub of course, if you leave the iPad in the kitchen it won’t be on the sofa when you want to choose an album or playlist on the main system.

, Introduction to streaming

The playlist is another aspect of streaming that is very popular, essentially it’s a means of collecting a selection of tracks in a list that can be saved. It’s a bit like a compilation tape but a lot more flexible as you can have almost as many tracks as you like and you can have the same track on as many playlists as you want. As an old school album listener this is not something I have adapted to in truth, I tend to play tracks or albums but rarely get around to building playlists despite the ease with which it can be achieved. But I get the impression I am in the minority in this regard.

 

Formats

I mentioned formats earlier, there are many of these to choose from but if sound quality is important then the list gets a lot shorter. The choice is essentially between those that losslessly compress the audio data such as FLAC and Apple’s variant ALAC, and those that do not: WAV, AIFF and more recently DSD. The reason for choosing the lossless formats used to be that they require about half as much storage space, but now that space is so inexpensive that is less valid. What is more important is metadata, all the information about the track including artist, track title, album title, artwork etc. FLAC, ALAC and AIFF all support metadata, which means that if you transfer your music collection to a player that uses different software it will be able to display this key information.

However, WAV is regarded by many to be the best format, it’s not Apple specific like AIFF and it does not compress data, and so long as you stick with the same software the metadata is available. It was the exclusive format of the Naim Unitiserve until last year when FLAC became an option. The thinking today seems to have swung toward FLAC because of its portability and the fact that a good streamer has no difficulty ‘unpacking’ the FLAC container to expand the data within. The fact that high resolution music files are sold in this format is a factor but possibly more significant is that not many people can hear the difference on most streamers. Linn’s position is that there is no audible difference.

DSD

On the other side of this fence is that revival of the format that SACD was based on, DSD. A format for which very little mainstream original content is available yet which has become the flavour of the season in the world of DACs. Even Naim has incoprated DSD compatibility in its NAC‑N 272 streaming preamplifier, this despite the fact that the Unitiserve that it sells to complement its streamers is not yet DSD compatible. You can get server software that will stream DSD however, Naim use one called Minim for their dems.

Another approach to streaming hardware is exemplified by the Auralic Aries among a few others, the Aries is a bridge which is essentially a streamer without a DAC. It has USB output for high bit/sample rates as well as S/PDIF outputs on coax and optical. The absence of a converter and analogue output stage makes it less expensive than a high end streamer but theoretically able to compete with such things if you have a serious DAC already. There are not many bridges on the market yet but a high end British example turned up at the Bristol show this year, the Stack Audio Onset with its dCS style casework looks very promising.

Online sounds

As well as providing easy access to your own music collection a streamer also opens up the world of internet radio and streaming services. There are seemingly millions of net radio stations around the world that can be searched for by region or genre, and many can only be accessed online. If you are looking for niche programming there is no easier way to find it and while sound quality is variable it’s not a lot worse than other digital broadcasting. In some cases companies get exclusive access to higher quality streams, Naim streamers provide both Naim Radio and Radio Paradise at 320kbps for instance.

, Introduction to streaming

Streaming services are more like an online library from which you can pick and mix tracks, albums and artists. For sheer breadth of catalogue it’s hard to beat Spotify but that is limited to 320kbps on its £10/month premium service or 128kbps otherwise. There are two services that offer CD quality streaming, these are Quboz from France and Tidal. The catalogues from both are large and growing, but not in the Spotify league yet, and don’t include certain major artists, the Beatles are not represented and neither are artists on the ECM label which is perhaps more pertinent. Quboz has a considerably larger classical library of the two and offers a 15‑day free trial, Tidal’s is only seven days unless you can pick up a voucher at a show. Both services cost £20 a month and sound quality is pretty good, not up with your own library but good enough to enjoy on a decent system.

, Introduction to streaming

Since this feature was written, Apple has announced its own upcoming Music service.

Conclusion

Streaming has not quite scaled the sonic heights of the best analogue and digital sources and being a young technology in audio terms there is room for improvement in the software provided by some companies. That said it is 21st century audio technology that doesn’t cost a fortune. I use streaming for the majority of my reviewing work, it doesn’t sound as good as my turntable but it’s pretty damn fine and a whole lot more user friendly.

Tags: FEATURED

Adblocker Detected

"Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit..."

"There is no one who loves pain itself, who seeks after it and wants to have it, simply because it is pain..."