High-res audio (HRA) has emerged as the ultimate choice for digital music fans, but what's it all about, what do you need and where can you get it? Allow us to explain.

2014 has been the year that high-resolution audio (HRA) has begun to build-up a head of steam, with new products and services being launched to take high-res audio in to the mainstream.

The industry has been transformed by digital downloads from sites such as iTunes, marking a shift away from physical media like vinyl, tapes and CDs. Formats including MP3 and AAC make it easy to buy, listen and store our tunes.

With regards to sound quality, however, these formats just don't cut the mustard. The use of lossy compression means that data is lost in the encoding process, which means resolution is sacrificed for the sake of convenience and smaller file sizes.

This might be fine on the bus when you're listening to your iPod or smartphone, but serious music fans want better. This is where high-resolution audio – or HRA, as termed by the Consumer Electronics Association – steps in.

Astell & Kern, LG, Samsung,  Sony and  FiiO are among the companies to have launched high-resolution audio products this year, while several download sites now offer better-than-CD quality music files, with the likes of HDtracks and Qobuz now live in the UK. HRA also has the support of major labels and musicians.

What does high-resolution audio actually mean? Where can you get it? What do you need to play it on? Don't worry – all your questions and more are answered on this page. 

What is high-resolution audio?

Before we address this, it’s worth pointing out that the definition of high-resolution audio isn’t set in stone. Unlike high-definition video, which has to meet certain criteria to earn the name, there’s no universal standard for high-res audio. 

But it tends to refer to audio that has a higher sampling frequency and bit depth than CD, which is 16-bit/44.1kHz. High-resolution audio files usually use a sampling frequency or 96kHz or 192kHz at 24-bit, but you can also have 88.2kHz and 176.4kHz files too.

Sampling frequency means the number of times samples are taken per second when the analogue sound waves are converted into digital. The more bits there are meanwhile, the more accurately the signal can be measured in the first place, so 16-bit to 24-bit can see a noticeable leap in quality.

The Digital Entertainment Group, Consumer Electronics Association and The Recording Academy have, together with record labels, come up with a formal definition for high-res audio

As well as the definition - "Lossless audio that is capable of reproducing the full range of sound from recordings that have been mastered from better than CD quality music sources" - there are four different recording categories based on the source of the file.

There are several high-resolution audio file formats to choose from, all of which support the above sampling rates and bit-depths. They include FLAC (Free Lossless Audio Codec) and ALAC (Apple Lossless Audio Codec), both of which are compressed but in a way that (in theory) no information is lost.

Other formats include WAV, AIFF and DSD, the format used for Super Audio CDs. The relative merits of the formats can be argued but most crucial will be compatibility with your particular products and system.

FLAC tends to be the most popular, scoring points over WAV for better meta-data support, ensuring your tracks have artist and title information. There's a healthy debate on the whathifi.com forums on the subject of FLAC vs. WAV.

Of course, as well as downloading your music in these superior formats, you can - and should - also rip your existing music library in these higher-quality file formats.

What’s so good about high-res audio?

Obviously the main claimed benefit of high-resolution audio files is superior sound quality over compressed audio formats.

To illustrate why they should sound better than MP3s, for example, let’s compare the relative bitrates. The highest quality MP3 has a bitrate of 320kbps, whereas a 24-bit/192kHz file is transferred at a rate of 9216kbps. Music CDs are transferred at 1411kbps.

24-bit/96k or 24-bit/192kHz files should therefore more closely replicate the sound quality that the musicians and engineers were working with in the studio.

With more information to play with, high-resolution audio tends to boast greater detail and texture, bringing listeners closer to the original performance.

Though, as always, there are some people that can't hear a difference. As with all the products we review, if you can't see or hear a difference, then save your money... 

MORE: High-res audio - the science behind the numbers

Where to buy and download high-res audio?

There are currently only a handful of UK download stores, but the number is likely to increase with several new services rumoured to be launching in 2014.

There are several US and European sites but not all of them let you purchase from the UK. Here are a few of the best:

HDTracks

Pioneering US high-resolution music store HDTracks is now available in the UK, initially launching with more than 10,000 uncomprossed high-resolution albums.

The company says it has partnered with every major record label – including Sony Music Entertainment, Warner and Universal – to create the world's largest catalogue of high-res audio files.

HDTracks has also announced a deal with Liztic, a music management application that aims to deliver a seamles digital music experience across PC, Mac, Android and iOS.

Naim Label

Better known for its home entertainment systems, Naim has a nifty sideline in hi-res audio files, including music from its own Naim Label.

Its site offers music in 320kbps MP3s right up to 24-bit/192kHz WAV, FLAC and ALAC files. High-res albums cost between £9.99 and £16.99.

Linn Records

Linn’s website offers what it calls Studio Master downloads in 24-bit/192kHz FLAC and ALAC, as well as 24-bit/96kHz, 16-bit/44.1kHz and 320kbps MP3 formats. A Studio Master album costs £18, or £10 in CD quality.

Bowers & Wilkins Society of Sound

Another hi-fi brand that turned its hand to hi-res downloads, B&W’s site boasts a range of studio-quality albums. You can also subscribe and access albums not available in the store. Files are available in 24-bit and cost £15.

PonoMusic

Neil Young's long-awaited Pono high-res service looks finally set to launch, with news that a Kickstarter campaign will make the PonoPlayer available to buy. The PonoMusic service promises DRM-free high-res downloads from major and independent labels and there's a dedicated music management software application, too. You can read our first impressions of the Pono PonoPlayer for more details.

Qobuz

French website Qobuz launched in the UK back in August and offers in excess of 20,000 high-resolution albums. Files are available at a minimum of 16-bit/44.1kHz while many are offered in 24-bit/192kHz. High-resolution files are also available through the Qobuz streaming service.

Other sites: 

2L – Norwegian site offering up to 24-bit/96kHz and multichannel DSD

7Digital – Offers 24-bit FLAC downloads

Gimell – Studio Master 5.1 downloads in 24-bit/96kHz

HD Klassik – Classical music high-res downloads

And earlier this year Sony, Warner and Universal announced that they will make their extensive music catalogues available to hi-res download services – all of which will be a real shot in the arm for fans of high-resolution audio in this country.

With all sites, make sure it's clear what file format and bitrate you are buying and let us know your experiences with using these and any other HRA websites in the comments below.

What do I need to play it?

From AV receivers and stereo amps to all-in-one music systems and streamers, a growing number of products on the market are handling high-resolution audio. 

As yet, there remains a certain amount of variation when it comes to file handling and maximum bitrate support on different devices, so check the specifications match your requirements before you buy a new product.

Some systems allow you to play high-res files directly from USB storage devices or from a networked PC via Ethernet. 

You can also play high-resolution audio stored on a PC by connecting it to a USB DAC like the Arcam irDAC (pictured, above), the Naim DAC-V1 or the T+A DAC 8, then feeding it to a power amp, powered speakers or headphones.

Complete systems, such as the Monitor Audio MA100, now supports high-res audio (as well as wireless streaming features), while companies such as Sharp have also  got in on the act.

You can even buy dedicated headphone amps with built-in DACs that handle high-res audio. The ever-popular Sonos system supports WAV and AIFF files but only up to uncompressed CD quality.

However, you will need a high resolution audio player, as not all music software is compatible. iTunes will play high-res files but not  FLAC files, for example.

If you're on a Mac, you can try Amarra or Channel D's Pure Music. We also hear differences in sound quality, so it's worth experimenting. On a PC? Try JRiver Media Center

High-res music on mobile

High-res audio isn’t just confined to the hi-fi market. Several of the latest smartphones play music in sparking 24-bit/192kHz quality, including the  LG G3Sony Xperia Z3 and  Samsung Galaxy Note 4, while the  Onkyo HF Player app allows you to play high-res music on any compatible mobile phone.

The iPhone 6 sadly doesn't support high-res audio out of the box but there is the potential to connect devices via the Lightning output rather than the headphone jack to send a digital audio signal.

The Philips M2L headphones are the first to use the Lightning connection, bypassing the iPhone's internal DAC to instead use their own high-res capable DAC.

 

 

Best high-res audio streamers

Best music streamer under £600

Pioneer N-50 

Five stars

Tested at £500 – compare prices

"A price cut makes this Pioneer even more of a superstar"

 

More after the break

Best music streamer under £1000

Cambridge Audio Stream Magic 6

Five stars

Tested at £699

"Looks good, easy to use, sounds great and has a list of uses longer than your arm"

 

Best music streamer under £2000

Naim NAC-N 172 XS

Five stars

Tested at  £1650

"An engaging and high-res happy performer – and a real star turn at the price"

 

Best music streamer £2000+

Cyrus Stream XP2-QX

Five stars

Tested at £2300 – compare prices

"This superb streamer sounds absolutely fantastic"

 

MORE: Awards 2013: Best music streamers

High-res music player reviews

High resolution audio doesn't have to be saved for home listening anymore. Companies such as Sony and Astell & Kern believe we should be able to access high-resolution audio on the move, and as such, have produced portable high-resolution music players.

 

Sony NWZ-ZX1

Four stars

£550, tested 28.01.14

Sony impressed us with its first attempt at a high-res music player, thanks to seriously good sound and a lovely design, but it is expensive and is missing expandable memory and DSD support.

MORE:  Sony NWZ-ZX1 review 

 

Astell & Kern AK100 Mk II

Four stars

£700, tested 10.03.14

A seriously talented performer from the portable audio experts (and the high-end brand of established manufacturer iRiver). It's not without flaws – the storage capacity and sluggish interface – but the quality of the sound is good enough to make us forgive many of the AK100's flaws.

 

MORE:  Astell & Kern AK100 Mk II review

 

Sony NWZ-F886

Five stars

£240, tested 11.07.14

One of the best portable high-res music players on the market today, the F886 delivers high-resolution tracks with supreme precision. It could do with a little more volume at times, but otherwise the NWZ-F886 is our music player of choice. The fact it's built around the Android operating system, granting access to the app store and web browsing make it a lot more desirable. 

MORE: Sony NWZ-F886 review

 

Fiio X5

Four stars

£290, tested 21.07.14

The X5 sounds great with high-res music but not quite so impressive as it should with lower resolution tracks. We're not convinced by the design either and no onboard memory seems like an oversight. Still, worth checking out if you're on a tighter budget.

Fiio X5 review

 

iBasso DX50

Four stars

£200, tested 23.07.14

Much like the Fiio player above, this iBasso is nowhere near as competent with standard-def music as it is with higher resolution tracks. Luckily, it's detailed and exciting when you give it the good stuff to play. A retrograde user interface is a little underwhelming but it's another solid if not spectacular portable music player.

iBasso DX50 review

Upcoming music players

Astell & Kern AK240

Unveiled at CES, the flagship Astell & Kern AK240 was one of our Stars of CES winners, and features a 256GB internal memory and a microSD card slot supporting up to 64GB of extra storage. It can play DSD files without having to convert them, and will also stream music from a NAS device.

 

Sony NWZ-A15

Sony's new budget high-res Walkman is the A15, which for just £170 offers 16GB of storage and a microSD card slot. There's no touchscreen like the other Sony Walkmans but you do get a hefty battery life of up to 50 hours. Read our A15 hands-on review for our first impressions.

 

 

Multi-room high-resolution audio

Multi-room audio products have seen a major boost in 2014, with many manufacturers looking to expand their product arsenal's or new manufacturers looking to steal the limelight away from current multi-room audio champion, Sonos.

Bluesound entered the market in 2014, promising high-resolution, 24-bit audio across the entire range. Sonos can only stream in CD-quality 16-bit/44.1khz.

MORE: Bluesound HD wireless music streaming system takes on Sonos

Products in the range include the Node wireless streamer, Powernode standalone streaming music player, Vault high-resolution music server, Pulse all-in-one music streaming system and Duo 2.1 speaker system and subwoofer. 

Other multi-room audio systems have since followed suit, with systems such as the LG Music Flow, Lenco PlayLink, Harman Kardon Omni and Monster SoundStage all offering high-res support on their new wireless speaker systems.

MORE: Multi-room audio: everything you need to know

What's next?

Since receiving its own dedicated zone at CES 2014, high-resolution audio has gained a lot of traction in 2014. Manufacturers including Bowers & Wilkins, Naim and Linn have been pushing for and producing high-resolution audio products for some time. We've now seen mass-market heavyweights such as Sony, LG and Samsung adopt the format to bring it to a larger audience. 

With this wider availability, more people are able to learn and understand exactly what high-resolution audio is, and the benefits it brings to music listening. 4K Ultra HD televisions are gaining traction in the home cinema field, but there's not a lot of content available at the moment. With high-resolution audio this isn't the case, there's plenty of content out there - now we're getting the hardware to go with it.

Moving in to the end of 2014 and into 2015, we expect more manufacturers to produce more affordable products, allowing consumers to hear music in a completely different way.

 

OPINION: The science behind the high-res audio numbers

 

Comments

StanleyAV's picture

DRM/copy protection within the analogue audio???!!

How do we know that Sony with its technology and downloads has not
secretly placed "audible"(?) watermarks within the analogue domain?

It is quite happy to pollute the audio for Cinavia enabled Blu-Ray releases?
I can see that dirtying the audio for hi-res would be unconscionable
for audiophiles but sorely tempting for Sony and the record industry.

Thoughts, Whathifi?

narfybob's picture

False advertising

"Obviously the main benefit of high-resolution audio files is their superior sound quality over compressed audio formats and CDs. ... With more information to play with, high-resolution audio tends to boast greater detail and texture, bringing listeners closer to the original performance than ever before."

This is completely false. Where did you get the information that higher-resolution music automagically means it sounds better? Scientifically published findings, basic electrical engineering concepts, and myriads of ABX testings have demonstrated humans can't distinguish between a high-resolution music file and that same file down-sampled to CD quality.

 

Bit depth only affects quantization error noise, and thus the noise floor. A bit depth of 16 already has a low enough noise floor and dynamic range for even very dynamic classical music for consumer playback. Were music to utilize the full 24-bits of resolution available in a 24-bit recording, the music would have enough dynamic range to seriously damage our hearing. Such bit depths are only useful for studio applications where the engineers work and with the audio signals and the extra headroom is required for sound manipulation, NOT for the sound quality.

 

Sample rates of 44.1 kHz or higher do nothing useful to the end listener since the Nyquist sampling theorem states that a signal can be perfectly replicated with a sampling frequency twice as much as the highest frequency captured. Human hearing has a limit of 20 kHz, if not less due to age and deafness. That means a signal can be accurately captured with a sampling rate of 40 kHz. It's been demonstrated through scientific testing that high-frequency reproduction in audio equipment can be harmful to the sound quality since aliasing from the higher frequencies folds into the audible range.

 

I highly suggest doing some basic research first before you publish this propaganda.

http://xiph.org/~xiphmont/demo/neil-young.html

http://www.aes.org/e-lib/browse.cfm?elib=14195</p></div>

http://www.aes.org/e-lib/browse.cfm?elib=13967

http://www.ece.rutgers.edu/~orfanidi/intro2sp/orfanidis-i2sp.pdf

http://en.wikipedia.org/wiki/Nyquist_sampling_theorem

http://en.wikipedia.org/wiki/Audio_bit_depth

http://www.innerfidelity.com/content/its-masters-damit

http://www.youtube.com/watch?v=nLEhfieoMq8

http://www.sonicscoop.com/2013/08/29/why-almost-everything-you-thought-you-knew-about-bit-depth-is-probably-wrong/

http://audioxpress.com/files/galo2941.pdf

 

 

This is exactly why the Pono Player has so much resistance amongst the hi-fi folks. They have the right intentions, but they're using and actively advertising the wrong information to the common consumers and media outlets, so they are in essence being fed false advertising. It's absolutely KILLING us people who actually know better!
As stated in the Innerfidelity article, one user commented:
"What will ultimately happen is that they will damage the hobby and industry as a whole with this misleading advertising."

offskooring's picture

so...what you guys have to

so...what you guys have to say seems pretty legit...my question would be...what should i focus on for quality playback of digital files?

Lazy-1's picture

Wimp HiFi ...

... is another CD quality streaming service that deserves mention. Flac and Alac.

jimbo20004000's picture

Sound Quality

Narfybob is correct. I have worked in various studios over the years. 16/44.1 (or 48) is high enough sample rate and resolution to cover anything a human can appreciate. Especially when using consumer quality audio reproduction equipment. We use much higher quality mastering equipment; for example PMC active speakers which cost many tens of thousands of pounds. Play a CD quality track through those and trust me they give all the detail, dynamics and overall sound quality you could wish for. 

16/44.1 sound quality is dictated by the quality of the audio recording process. Simply increasing the resolution and sample rate will not magically increase sound quality. Analogue to digital conversion and the whole editing process has greatly improved since the eighties, which is why CD's mastered back then did not always sound so good. These days a well mastered CD or FLAC equivalent will sound exactly the same as the 24/192 version. I listen through 100K worth of PMC active speakers, and we cannot tell any difference. We do record much higher than the 16/48 we used to, to allow easier editing; but i can asure you no perceivable sound quality is lost when converted down to 16/44.1.  

The Nyquist sampling theorem does indeed apply. It is basic mathematics and physics applied to audio. No marketing talk here i am afraid. Also no DAC or ADC can resolve a full 24 bits as the last few bits of data are lost in noise/distortion. (until they can develop a room temperature superconductor that is). Anyone with an understanding of electronics/maths and physics will know this.

 

Ah Lau's picture

CD vs Hi-res

CD quality bit rate is 1.411Mbps, the 192kHz/24bit Hi-res audio bit rate is 9.216Mbps. it means the audio signal is 6.5X more data compare to CD.. the audio signal is more close to true audio....  

jimbo20004000's picture

Reconstructing the analogue

Reconstructing the analogue signal is not made more accurate by increasing bit depth and sample rate, and it will NOT increase sound quality. 16/44.1 covers the frequency range and dynamic range required for human hearing limitatations. Increasing data rate does not increase percievable sound quality. The Nyquist sampling theory covers the mathematics to prove this. It is the recording process and then the reproduction process which determines overall sound quality. The reason some recordings higher than 16/44.1 may sound better is because they were recorded and produced to higher standards in the first place. They use a higher quality master. To put it another way, a recording made at 24/192 can sound worse than one at 16/44.1. 

http://mathworld.wolfram.com/SamplingTheorem.html

This short educational video explains and proves why 16/44.1 is easily enough to record and reconstruct the original analogue waveform. Increaing bit depth simply increases dynamic range and lowers noise, which is ok for studio use; but 16/44.1 is already low enough noise and high enough dynamic range for human hearing limitations. Increasing sampling rate to 96 or 192Khz is pointless, as all it does is introduce problems such as intermodulation distortion. It makes zero difference to the accuracy of the original analogue waveform being captured. Anyone with a basic understanding of electronics and mathematics knows this. Hence the comment that increasing bit depth and sampling rate will more accurately capture the original analogue waveform, is not mathematically correct.

http://xiph.org/video/vid2.shtml

http://people.xiph.org/~xiphmont/demo/neil-young.html

http://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem

offskooring's picture

so...what you guys have to

so...what you guys have to say seems pretty legit...my question would be...what should i focus on for quality playback of digital files?
 

wombledon's picture

Just done a comparison with

Just done a comparison with 320kbps mp3, CD, and HD version of the same track, and with reasonable headphones (Sennheiser HD565) and Traktor Audio2.

Each step up in quality sounds cleaner, more precise stereo imaging, just more life-like. 

Sampling rate of 2x the highest frequency obviously isn't as good as it gets for those with discerning ears.

andyjm's picture

Maths is maths, and unless

Maths is maths, and unless you are a medical phenomenon, then 20Khz, 96dB (CD's range) is enough for anyone. 

That's not to say the tracks you tested didn't sound different.  Most differences in tests like yours come down to different masters.  Unless you started with the HD track and made the 16/44.1 and the MP3 track yourself, then there is every chance that the starting point of the 3 versions was different.

It is also not a given that your hardware does an equally decent job of reconstructing the 3 versions. Perhaps the designer spent more time worrying about the hires portion than the CD quality chain.

When properly conducted tests are performed, with music sourced from the same master and played back through level matched equipment, there are no tests to justify that 24/96 can be distinguished from 16/44.1 

I am afraid that the truth is that it is just marketing.

 

alex30's picture

Smoke and Mirrors

I totally agree with all the posters who point out that no one can tell the difference between Hi Res or Ultra Res and CD quality recording. The extra frequencies are beyond the range of human hearing. This is not debatable. It is fact.                                                                                      I do disagree that it will ruin the industry. The Hi Fi world has long been beset by myths , legends and lies. Take , for example , the whole unscientific approach and witchcraft surrounding the promotion of  loudspeaker cables and interconnects. These simple pieces of wire are said to open up the sounstage, add detail, precision and dynamics. But only if you pay an exorbitant fee so that you can join a select few and own our cables. Can anyone , who has not been certified insane, please explain to me how a cable can improve sound staging? I have news for you, it is not possible.                                                                                                                  Music will survive this latest attempt to scam us out of our money but it does those involved no credit at all.