MP3 Vs. FLAC: Which Is The Better Format?
The Compact Disc (CD) is an optical disc used to store data. This format was developed by Philips and Sony in 1982. It revolutionised the way we listened to music. It sparked the beginning of the digital era for A/V consumers. After 30 years and more than 30 billion discs in sales, the format is now at an all-time low in sales all over the world. In fact, last year, the sales of Vinyl Records have surpassed that of CDs in the USA. We are currently at yet another threshold where the future definitely belongs to ‘disc-less’ playback for both audio and video enthusiasts. As of today, one can buy A/V downloads and stream it through a High Fidelity (Hi-Fi) A/V playback system, using a computer, without the need for buying media discs or media specific disc players. MP3 Vs. FLAC, the debate on which format to adopt, is more valid today for audio enthusiasts than it ever was. Let’s look at some of the details that goes into both formats before casting our votes on our favourite audio format.
Lossy Compression Vs. Lossless Compression
Lossy compression is a data encoding method that compresses data by discarding (losing) some of it to minimize the amount of data that needs to be held, handled and transmitted by a computer or a portable media player. Typically, a substantial amount of data can be discarded before the result is sufficiently degraded to be noticed by the user. A popular example of lossy compression is MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3.
Lossy compression is most commonly used to compress multimedia data (audio, video and still images), especially in applications such as streaming media. In many cases it is advantageous to make a master lossless file that can then be used to produce compressed files for different purposes. For example, a CD consisting of Waveform Audio File (WAV), an uncompressed format, can be ripped and converted to a 320 kbps MP3 format for use with a low capacity portable media player. The master WAV copy can also be converted to Free Lossless Audio Codec (FLAC), which is a lossless compression format that allows tagging information, such as album art and song details, and then streamed to a Hi-Fi A/V playback system using a Laptop or Multi-Media Player.
Lossless data compression on the other hand allows the exact original data to be reconstructed from the compressed data. The term ‘lossless’ is in contrast to ‘lossy’ data compression, which only allows constructing an approximation of the original data, in exchange for better compression rates.
Lossless compression is used in cases where it is important that the original and the decompressed data be identical, or where deviations from the original data could be deleterious. Lossless audio formats are most often used for archiving or production purposes, while smaller lossy audio files are typically used on portable players and in other cases where storage space is limited or exact replication of the audio is unnecessary.
Bit Rate Vs. Bit Depth
Mp3 is still the most popular format for digital music. When we talk about downloading music in the MP3, it’s all about the bit rate. You probably know that computers use zeroes and ones to represent data, and a bit is a single zero or one. The bit rate of an MP3 refers to how many of those zeroes and ones per unit time are processed both when the track was encoded and when it’s decoded or played back. The more bits per unit time, or the higher the bit rate, the closer the MP3 will sound to the original wave form that it represents. When the bit rate is too low, the MP3 will have what is called artefacts, it will introduce noise that wasn’t present in the source material and basically ends up sounding like your music is coming out of a radio channel, lacking dynamics and details, instead of a Hi-Fi A/V playback system, and that’s not good.
The highest bit rate that is available for MP3 is 320,000 bits per second (320 kpbs). By comparison, CD quality is about 1400 kbps in WAV. While a higher bit rate MP3 will give you superior sound quality, it is claimed that most people can’t tell the difference between a 256 kbps MP3 and CD quality, and practically no one can with a 320 kbps file in a double blind test. Though purists with better fidelity A/V playback systems may disagree with this claim.
FLAC is one of the most popular formats for archiving audio. When we talk about downloading music in FLAC, it’s all about the bit depth. Bit depth describes the number of bits of information recorded for each sample. Bit depth directly corresponds to the resolution of each sample in a set of digital audio data. Some examples of bit depth include CD quality audio, which is restricted at 16 bits (due to the media’s capacity limitation), whereas Super Audio CD, DVD-Audio and Blu-ray Disc can support up to 24-bit audio. So essentially, MP3 is restricted to 16-bit audio as it is compressed from WAV (CD) and FLAC can support up to 24-bit audio depending on the source to be compressed.
There is some disagreement over the recent trend towards higher bit-depth audio. It is argued by some that the dynamic range presented by 16-bit is sufficient to store the dynamic range present in almost all music. In terms of pure data storage this is often true, as a high-end system can extract an extremely good sound out of the 16-bits stored in a well-mastered CD. However, audio with very loud and very quiet sections can require some of the above dithering techniques to fit it into 16-bits. This is not a problem for most recently produced popular music, which is often mastered so that it constantly sits close to the maximum signal (loudness war); however, higher resolution audio formats are already being used, especially for applications such as film soundtracks, where there is often a very wide dynamic range between whispered conversations and explosions.
For most situations the advantage given by resolution higher than 16-bit is mainly in the processing of audio. No digital filter is perfect, but if the audio is upsampled and the audio is done in 24-bit or higher, then the distortion introduced by filtering will be much quieter, as the errors always creep into the least significant bits, and a well-designed filter can weigh the distortion more towards the higher inaudible frequencies, but a sample rate higher than 48kHz is needed so that these inaudible ultrasonic frequencies are available for soaking up errors.
Constant Vs. Variable Bit Rate
In addition to a constant bit rate, where the bit rate stays the same, there are also variable bit rates. With a variable bit rate, the bit rate changes depending upon the complexity of the source material. If you imagine a full orchestra all playing at once versus a solo acoustic guitar, the orchestra is going to require a higher bit rate to sound faithful to the source because the waveform is more complex and contains more sonic information. So with variable bit rates the bit rate decreases when less information is required to give an accurate representation of the wave form. The highest bit rate variable files are sometimes called ‘V0’ for short. Typically a V0 file will have an average bit rate somewhere around 225 kbps, but as you might guessed from the name, it varies.
MP3 Vs. FLAC
MP3 is what is called a ‘lossy’ format, which means that as the waveform is compressed some of the information is omitted as the MP3 is encoded. As mentioned earlier, this isn’t so much of an issue with 256 and 320 kbps bit rates because the MP3 is close enough to the original waveform that our ears have trouble picking out the missing frequencies. That said, there are lossless formats where the file will be an exact copy of the source. Even though FLAC is lossless and you don’t lose any fidelity from the original source, it is still compressed. The way it works is that the file is uncompressed as it is played by the software you use for playback. Since it is compressed, the file is about two thirds of the size of an uncompressed WAV. However FLAC files are still quite large. A typical album in MP3 at 320 kbps will take up around 120 MB of space, whereas the same 16-bit album in FLAC will be in the vicinity of 400 MB. The drastic difference in size is because the FLAC files have a much higher bit rate of 900kbps or more, which means more data per unit time.
MP3 has an advantage in that they will take up less space on your computer, iPod, iPhone or wherever you store your music. Another drawback to FLAC is that it is not supported by iTunes, however Apple has their own version which is called ALAC. Alternatively, iTunes offers a third party software called ‘FLAC Player’ for USD 10 (equivalent of INR 600) which allows playback of FLACs in iPods and iPhones. There are a couple of free popular media player software options that do support FLAC such as Foobar2000 and Winamp for use with Laptops and Computers.
These days storage is not as much as an issue as it was before with hard drive sizes becoming larger and cheaper. Basically you want to download the file with the highest available bit rate that you have space for, and that will be compatible with your playback method whether it’s a physical media player like an iPod or software like iTunes or windows media player. If you do go with MP3 then a bit rate of 256 kbps or 320 kbps is highly recommended.
It all comes down to how serious you are about music playback. If you are someone who listens to free downloads in an all-in-one music system, car stereo or MP3 player then opting for the 256 or 320 kbps MP3 is a good, practical and affordable option. If you are someone who already has a vast collection of original CDs and now plan to stream your entire collection to your Hi-Fi A/V playback system through a Laptop, Computer or Multi-Media Player, then ripping your entire collection into 16bit/48kHz FLACs will offer you the best possible experience.
If you are a hard-core audiophile with ‘golden ears’ and you demand nothing but the very best audio format, that resembles the master studio copy, then you now have the option of buying very select High Resolution (HiRes) studio recorded or remastered album in 24bit/196kHz FLAC downloads, directly from any of the service provider’s website. These HiRes files have bit rates that may exceed 2500kbps, each file size may exceed 200MB and an entire album may exceed 1.5 GB in total size. Of course, a Digital to Analogue Converter (DAC) that can handle 24bit/196kHz is needed in your A/V playback system to make the best of the above format.
You may also choose any other ‘lossless’ format that best suits your practical needs, depending on the kind of devices you currently have. Most ‘lossless’ formats can actually be converted from one type to another without any loss in data. It’s a good practice to back-up your ‘lossless’ files in a spare Hard Disk Drive (HDD) just in case if you ever happen to lose your main HDD. If you are still unsure of which format to adopt, then I suggest that you test drive your A/V playback system with free HiRes 24bit FLAC sample downloads from 2L – The Nordic Sound’s website and see if the difference in quality is audible to you. For more details on the free HiRes downloads please click on this – LINK.
The time is just right to migrate from ‘disc’ to ‘disc-less’ A/V playback systems. CD players and Blu-ray players are slowly giving way to computers in today’s Hi-Fi racks. The development of Asynchronous USB (Universal Serial Bus) and HDMI (High Definition Multimedia Interface) interfaces have further helped computers to step up as a quality source in many Hi-Fi A/V playback systems.