17 June 2009
Digital Audio Formats - Lossless Audio
For those of you who appreciate audio at a quality that comes close to matching the original performance, you would be forgiven for dismissing the storing and playback of music on a computer, media hard drive or portable music device.
So what might you be overlooking?
Well, there are two main types of digital audio formats, Lossy and Lossless. Although we are interested in the latter, we will take a brief look at the Lossy format history.
Lossy
The most commonly known and used Lossy format is MP3 (MPEG-1 Layer 3), where music is typically stored digitally in a compressed form , from 128kbps to 320kbps*. - the higher the digital bit rate the better the quality.
Music stored in 128kbps gives varied results which has lead to it receiving a bad name amongst the audiophile community.
The term ‘compression’ is a compression algorithm process used to interpolate the analogue signal into a digital format .
AAC, or Advanced Audio Coding (MPEG-4 AAC) has taken the MP3 formula and improved on it. It is often said that a 128kbps AAC file is comparable in quality to an MP3 file at 192kbps.
Microsoft have their own version of MP3, known as WMA. It’s premise was to provide a better quality than MP3 for the same file size. Whilst it does improve upon MP3, it is not a match for AAC.
Lossless
There are now a variety of Lossless compression algorithms that exist. These have been developed specifically with music in mind, whereas some of the aforementioned Lossy formats were data compression tools adjusted to work for music.
The following formats have been developed to overcome the errors which MP3 is infamous for.
Apple Lossless - ALAC (Apple Lossless Audio Codec)
Audio Lossless Coding - also known as MPEG-4 ALS
Free Lossless Audio Codec - FLAC
Meridian Lossless Packing - MLP
Monkey’s Audio - Monkey’s Audio APE
RealPlayer - RealAudio Lossless
TTA - True Audio Lossless
WavPack - WavPack lossless
WMA Lossless - Windows Media Lossless
It is important to carefully research which format you choose to adopt so that worst case you don’t have to rip your music collection again or carry out any conversion process! Some points to consider:
Experiment with a good quality music track that you know well, using different settings.
Cross platform/device compatibility (Free Lossless Audio Codec)
Manufacturer support (Apple Lossless Audio Codec)
Freeware (Free Lossless Audio Codec)
Global adoption, longevity of format
DVD Audio
Whilst it is not yet supported on portable devices, DVD-Audio offers a quality that far exceeds that of a CD. To put it in perspective, the quality available on a standard CD is 44.1KHz/16bit, where as DVD-Audio is capable of 192KHz/24bit.
Advantages
Having every track being handled as a perfect copy in one place with ease of use is superb. The added tagging benefits in searching, ‘Genius‘ type replay and the fact the file won’t degrade over time (like a record or damaged CD) is of great benefit. Digital downloading has now reached the point where the music in 24 bit is better than a CD can ever get!
Adopt one of the formats on offer and open up the potential of your music collection. Take it anywhere with you! Commute, car, exorcise, office and enjoy listening to music with friends. Rediscover your music collection via easy to search interfaces or even let cleaver software pick out a play list of similar genres at your request.
In a recent test using a number of high quality digital sourced formats, Driver Heaven awarded Sennheiser’s IE8 headphones the Editors Choice Award.
Whilst the IE range are as portable as any other in-ear headphone, it is their heritage that is of relevance here, evolving from studio in ear monitors offering an unaltered sound, allowing one to hear music as it was originally intended on the move.
Downsides
Well, not many really. When playing Lossless audio on a portable device, some people have reported up to a 40% reduction in battery life from each charge. But, given most manufactures quote 30+hrs playback, this I feel is a small price to pay and certainly still allows plenty of juice for your daily commute!
One other concern that was initially voiced was the storage capacity that is required. Again, with ever progressing technology providing almost double capacity devices year on year, this will become less of a sticking point in time.
Future
Like it or not, some big players in the Hi-Fi world have invested heavily to produce devices that cater for Lossless audio.
Naim Audio for example are taking this seriously and have acknowledged it with their site called ‘naim label‘, offering music in traditional formats but also FLAC. They have produced a media unit called the ‘HDX Hard Disk player‘ to store and playback digital music.
Linn have also produced a music dedicated site, Linn Records and have created a range of media units called ‘Digital Stream Players‘.
We have but scratched the surface here! Please share your knowledge on this developing area.
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- Audio Connoisseur
- Neumann KM-D Digital Mic in action
- The many flavors of wireless are all delicious
- World of Audio
- Spare Parts Finder
Tags: Advanced Audio Coding | ALAC | Apple Lossless | ATRAC Advanced Lossless | compression | Digital Audio | Digital Stream Players | DVD Audio | FLAC | Free Lossless Audio Codec | HDX Hard Disk player | Linn Records | Lossless | Lossless Audio | Lossy | Meridian Lossless Packing | Monkey's Audio APE | MPEG | Naim Audio | RealAudio | True Audio | WavPack | WMA | WMA Lossless
Interesting article. Thanks.
just to add that a new lossless audio compression alogorithm called “apt-X Lossless” has joined the Lossless pack. but in contrast to the existing types, “apt-X Lossless” can self-adjust (auto-adapt and scale) for optimal streaming over fading/noisy wireless channels, or maximising battery life in portable apps. (it also offers slightly better compression ratio than FLAC).
note also, that when it comes to “transcoding” - re-encoding previously decoded audio - some of the lossy formats introduce audible artefacts… so for stereo Bluetooth wireless, for example, a non-destructive audio coding scheme is better… SENNHEISER recently launched several new stereo Bluetooth headphone models featuring “apt-X” for full-bandwidth audio fidelity over wireless.
You don’t know what lossless and lossy codecs are.