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The Definitive Guide to 24-bit FlacHigh resolution downloads are changing the way we enjoy music, opening up possibilities undreamed of back in digitals early days
Its hard to understate the impact that Compact Disc made, upon its introduction back in 1982. At the time, the music world was very different, with vinyl regarded as the only serious way to play music. Found everywhere from broadcast studios to the local youth club, LPs were the worlds favourite music format. Still, at over thirty years old, black plastic was knocking on and sales were on the wane, down 40% from its 1975 high watermark. The scene was set for the brave new world of digital audio
What music lovers needed now was a small, convenient, high quality music carrier, and CD was it. Hailed as a miracle of modernity, it fused two technologies a digital audio coding system developed by Sony, and a laser optical disc storage system developed by Philips.
Legend has it that Sony had wanted the new Digital Audio Disc to be 12 inches wide, just like an LP, as they were worried that album artwork wouldnt look good on Philips proposed 5″ disc. Philips had wanted cardboard sleeves, just like LPs, but Sony insisted on a plastic jewel case to give the product a more tangible feel. So when CD finally emerged, it was full of compromises limited by the technology and what the big companies thought the public wanted.
Given that the average early eighties turntable could scarcely spin at the right speed, the new digital disc was a revelation. Sonically CD was was streets ahead of most peoples vinyl experience and had the added benefit of being immune from surface noise, static crackle and disc wear too. There were some golden eared hi-fi hacks around who didnt like its sound, describing it as a little stark and two dimensional. But by and large, CD was a quantum leap forward
Despite Philips famous description of it as giving pure, perfect sound forever, people soon started noticing problems however. Compared to analogue, early 16-bit digital could sound spiky and hard, giving cymbals and female vocals a coldness that just didnt seem right. Lab measurements showed that whilst CDs 16-bit digital system gave very low distortion on the loudest parts of the music, it distorted heavily on the quieter bits the exact opposite to how analogue LP behaved. Worse still, the digital system was prone to distorting most in the upper midband and treble, just where the ear is most sensitive
This was down to the way digital audio encodes the analogue musical waveform, and it applies to every format that uses the Pulse Code Modulation digital system, such as CD, MP3, AAC and FLAC. With PCM, the two basic factors that determine the sound quality are bit depth (which determines the quality with which the analogue signal is digitised), and the sampling frequency (which is the number of times per second that the analogue signal is digitised). CD is a 16bit, 44.1kHz system, giving a frequency response of 5-22,000Hz and 96dB dynamic range.
To understand this more clearly, its helpful to imagine taking a digital photo of a squiggly line. The more megapixels the camera that you use has, the higher resolution the snapshot will be and the smoother the squiggle will look. This is the visual equivalent of bit depth. Then try and imagine photographing that squiggle thousands of times a second.
The more snapshots you take per second, the more accurately you can track the way the line moves, kind of like seeing a flicker-free TV picture on a top television. Liken this to the sampling frequency, and you can see how the musical waveform (squiggly line) is captured digitally.
So the more bits you use, the more natural the music sounds, and the faster the samples, the wider the frequency range. CDs 16/44.1 digital system was state of the art in 1982, but it didnt take long for it to get past its sell-by date.
Malcolm Hawksford, Professor of Psychoacoustics at Essex University, reckons that, CDs digital specification was almost good enough for audiophile music reproduction. It was near the limit, but in my view probably a bit marginal. Ideally, at least 20-bit resolution at 60 kHz sampling frequency would have been better.
BIT BETTERCompact Disc became a technological time trap for audiophiles. Its almost-good-enough digital specification put the development of digital in suspended animation, locking us in to an outdated nineteen eighties way of digitising music. No surprise then that in recent years, many hi-fi purists have been turning back to vinyl which being analogue offers almost infinite levels of resolution. Analogue audio systems are limited not by digital bits, but atoms, argues Hi-Fi World magazines Paul Rigby. Where LP record playback fails is in the mechanical tolerances of the playback equipment, such as bearing friction and so on, rather than the resolution of the format itself. With digital though, it can only be so good and no better
Happily, DVD-Audio and Super Audio Compact Disc (SACD) arrived at the end of the nineties to save the day, offering far superior sound to CD. With the former offering true 24bit resolution, it came over as punchy and powerful with tremendous detail, plus a wonderfully smooth low distortion sound right across the audio band.
I have seen some really good recordings over the last decade where 16-bit was just not enough to hold all the information, says B&W digital research engineer Albert Yong., and given the opportunity to then listen to those recordings in 24-bits, they just blew the 16bit version out of the water.
Although 24-bit DVD-A sounded superb, it never got off the ground commercially. It was expensive, you needed a special type of DVD player and most importantly of all, retailers simply didnt want to sell it. With DVD video discs making the stores a mint (at the time), there was no reason to devote shelf space to less commercial audiophile music releases. DVD-Audos life was over just a couple of years after its inception, and no one missed it except a select bunch of audiophiles whod heard 24-bit digital and couldnt go back. But, whilst the disc went the way of the Dodo, its coding system would live on
Just as DVD-As sun was setting, so digital file downloads began making great inroads into the music marketplace. The MP3 format was no great shakes sonically but it was only the first wave; it might have sounded bad, but it ushered in a new way of obtaining music that no longer had any limits. Whereas CD was frozen in time and space, committed to its dated 16-bit, 44.1kHz flavour, internet distributed music could arrive in a way that suits the artist, label and listener.
Enter Free Lossless Audio Codec in 2001 which was an altogether more intelligent way of encoding music. Rather than the compressed system that MP3 used which reduces file sizes by about 80% by cutting out most of the music you cant hear (and some that you can), FLAC used a clever lossless packing system that doesnt remove any music at all, and saves about 30% to 50% of space. Its a problem-free system, says Professor Hawksford, if the arithmetic is performed correctly and the compressed files are not corrupted then there are no errors in the reconstructed output.
Whilst weve seen a number of lossless systems, from Apple Lossless (ALAC) to Windows Media Audio Lossless (WMA Lossless), the Free Lossless Audio Codec (FLAC) has emerged triumphant for music-loving hi-fi buffs. The spirtual successor to MP3, its an open-source system thats not tied to any one manufacturer, which explains it success. Better still, it comes in more than one resolution. Whilst you can encode your CDs to FLAC keeping their 16-bit, 44.1kHz resolution, FLAC can also come in 24-bit form too. The system is so flexible that it can take anything from 4 to 32 bits and sample rates up to 655350Hz in 1 Hz steps it can certainly replace 24/96 DVD-Audio, says Albert Yong.
BETTER THAN CDCompared to the mastertape, CD gives a decent but unsophisticated facsimile. Its 16/44.1 specification boasts a dynamic range of around 96dB, which is ample for most music work. The trouble is though, the quieter the signal is, the more the system distorts using the PCM digital system, which effectively sucks out the atmosphere all the subtle ambient details of a piece of music. In a direct A-B comparison with the mastertape, 16-bit sounds slightly vague, says Paul Rigby, like a primitive digital camera it simply loses the subtlety and fine detail; its less easy to live with than hi res digital
By comparison, Portico Quartets November via 24bit FLAC showcases the superior dynamics of the hi res file. A supremely atmospheric track, permeated with gently ringing kettle drums right through, its a far more engaging and arresting experience. Most people tend to think wider dynamic range simply means a louder, punchier sound, says Paul Rigby, but in a sense its closer to the reverse. Basically, it means all those quiet subtle sounds are far better resolved; theres a far greater sense of space and atmosphere, and the contrast between a gentle tap of cymbal and a smash of a snare drum is more faithfully rendered. The music just sounds more organic, and less like hi-fi.
Theoretically, 24-bit digital has a resolution of 144dB, which is more than enough (130dB is the threshold of pain for the human ear), but the problem is, as Professor Hawksford notes, of actually finding studios capable of recording at anywhere near this resolution. Not many recordings fully exploit the capabilities of CD, let alone higher resolution formats, he notes
Bowers &Wilkins Albert Yong agrees that were a good way away from achieving true 24-bit masters, but still we can do much better than old fashioned 16-bit, and people can easily hear the difference.
We have seen some extremely good recordings lately, when the entire recording chain is done right. We can potentially get up to around 20 to 22 bits at the moment, and they do sound a lot better. The difference is in the detail. Sounds generally are more open, and there is an extra level to airyness to the music. Voice and instruments sounds closer to live, and more dynamic as well.
THE MECHANICSLike any other music file, you can either rip FLAC copies of your existing CDs, or download load them from music sites such as Society of Sound. Weve structured our site to make downloading FLAC a breeze. After youve logged in, you will be taken to the Your Music section and youll see a menu of everything available. Its then simply a case of choosing an album and downloading the format you want. On Windows PCs, you can right-click on the link to save it to your desktop; with Macs, when you click on the download link it will go direct to the Downloads folder. Then you can simply copy-and-paste the file to where you want to keep it. We suggest having a folder labelled FLAC24′ or suchlike, so you know where your hi-res music has gone.
If youre looking to build up a FLAC library of your existing CD collection, then a good starting point for ripping is Exact Audio CopydBpowerAMP . which is a freely downloadable application for Windows, commonly thought to be one of the best sounding and most bug-free. Another much loved Windows FLAC tool is Mac Users can try running this via crossoverMac or downloading MacFlac .
Once youve downloaded your FLAC music, or ripped it from CD using the aforementioned applications, youll need to play it. Currently, neither Microsofts Windows Media Player or Apples iTunes support FLAC without modifications.
If you wish to import FLAC files to iTunes on MacOS we recommend you try a program known as Max for MacOS X 10, which can convert and rip PCM files and import them to your iTunes library. For more information please see here.
Both have their own equivalent (WMA Lossless and Apple Lossless) but these are tied to the operating system providers, whereas FLAC is of course a free, open source system like MP3. So for Windows-based systems, we recommend you download Winamp which is a highly flexible media player that also supports burning 16-bit formats to CD. There are other media players you may wish to try such as SongbirdMedia Monkey and Foobar2000 generally agreed to be the best sounding on the Windows platform. When you start up your music player, it should automatically search for all your digital music and add it to the library. SongBird will even go online and look for the artwork too, just like iTunes or WMP. which is a slick player for both Windows and Mac, with a nice clean interface. There are many other FLAC players, with
Through their bundled music players, both Microsoft and Apple have chosen to support certain file formats (WMA and AAC respectively). Whilst these players offer some flexibility (they both play MP3, for example), theyre both committed to their own Lossless formats. so FLAC is excluded. However, there are now bolt on FLAC players for iTunes emerging. Fluke is freeware that works as plug in for iTunes (Mac platform), but it is buggy and so cant be universally recommended yet. The forthcoming version Amarra Mini by Sonic Studio is a more sophisticated system that piggybacks on to iTunes, replacing much of its audio code with a superior sounding and more flexible system. It is expensive though at $395 US, and only works on Mac OS, so most users will choose to stay with a freely download separate player like SongBird.
Its easy to burn 16-bit FLAC files on to a CD-R for playback in a conventional hi-fi or car CD player. Winamp is a free player which also supports burning FLAC16 files to CD. If you wish to use a proper CD authoring software, then Roxio RecordNow MusicLab 10 (Windows, $29.99) or Roxio Toast Titanium (Mac. $99.95) are worth considering because the standard Windows or Mac music players wont handle FLAC, either 16 or 24-bit.
However, burning 24-bit FLAC is a more involved process, not helped by the fact that some popular software will appear to burn it to disc but actually down-samples it to 16-bit.
Once youve got your 24-bit FLAC files and FLAC player; now its time to get the music out to your ears. There are several ways of doing this:
The simplest is to take an analogue line output from your computer soundcard. This is likely to have a 3.5mm mini-jack plug; we recommend a high quality bespoke cable such as Chords iChord for around £30. Although it will give a decent sound, particularly if you have a good quality soundcard, it is not ideal because computers are electrically noisy environments, and it is best if at all possible to pipe out the digital signal away from the PC or Mac.
A good external soundcard like M-Audios Transit will always be a better sounding solution. This is a full 24/96 capable card, powered by USB. This provides a high quality S/PDIF optical digital output. It has an electrical coaxial digital output too, but it is always preferable to use the optical to eliminate computer-borne electrical noise. Run a good quality optical lead into a modern DAC such as a Cambridge Audio DAC Magic and you have a proper, high quality 24-bit FLAC playout system, that will give superior sound to almost any CD player. Its important to note here that Windows users should download the latest ASIO drivers; these provide a source direct function, ensuring the digital datastream goes direct from the FLAC software player to the USB digital output. Some of the latest DACs, like the Cambridge DAC Magic, also have USB inputs that can be driven directly from computers, but its always preferable to isolate the electrically noisy computer from the hi-fi by using an optical digital link.
Wireless streaming is the third, and for many the preferred option. Logitechs Squeezebox Touch ,£259, is one of the most inexpensive and convenient ways of getting full 24-bit FLAC replay at up to 96kHz sampling rate. It comes with bespoke playback software that lets your computer control it via your home wireless network, giving an iTunes-style user interface. Generally, these work very well and are an excellent way of giving multiform functionality. Although it has built-in line level analogue outputs which are ideal for use in a second system, again audiophiles should use its digital output into a hi-fi DAC, such as the aforementioned Cambridge Audio DAC Magic.
You can also check our recent 24-bit blog post to see how fellow audiophiles listen to 24-bit FLAC
THE EDGETheres an old maxim in the hi-fi industry, borrowed from the early days of the computer pioneers garbage in, garbage out. Any speaker can only be as good as the system driving it, and any system is limited by the quality of the original source material. Thats why B&W, as a manufacturer of premium, leading edge loudspeakers, takes FLAC very seriously. In 24-bit form its the modern day incarnation of digitals finest hour, DVD-Audio, but even better because its almost inflnitely upgradeable and future-proof. Professior Hawksford gives it the nod. FLAC has a place in the future for high quality audio. It is good for transporting files on the Internet as it typically halves download time. It is unlikely that for lossless compression there will be significant improvements, Hawksford believes.
The ease with which it can be delivered to a computer means that anyone whos capable of sending their friend a digital photo can now download and play high resolution FLAC files, and the benefits are clear for all to hear.
FLAC is as good as it can get for now. I think what it brings is not limited to quality of audio, but the added convenience as well, says B&Ws Albert Yong. The only drawback is the sheer scarcity of quality recorded music in 24-bit FLAC format, and thats where B&Ws Society of Sound comes in.
Meticulous attention to detail across the whole recording process with the latest high resolution digital recording systems, makes for music of unalloyed purity.
Thats why were so keen for you to experience 24-bit for yourself; once youve got the habit youll never look back.
