Pages

Thursday, November 14, 2013

Audio Quality

What you need to know



Sound is one of those things which we just cannot live without. Imagine a world without music. It is scientifically proven that there is a certain part of your brain that only responds to music. This shows how important music is.Everyone like to listen to high quality sound. It's soothing and sometimes it's all you need to take off the stress from a hard day's work.

Have you ever listened to a song using your cheap MP3 player and then one day listened to the same song via a friend's high end music player and you realised the song sounds so much better. You actually realise that there are details in that song that you didn't even know were there. No, you were not imagining things. Different hardware and software offer different sound quality output. 

Another thing that one has to pay attention is the quality of the music file you are listening to. Most of us listen to MP3 music and well, it sounds fantastic. MP3 is a lossy audio compression format. It is targeted towards low power music devices. There are newer lossy compression formats such as m4a, and AAC. These are just slightly better than MP3 but none compares to lossless formats like Flac.


Audio formats


Audio formats are file formats in which a music file is stored. There are two main types of audio formats. These are lossy formats and lossless formats.When music is recorded in a studio, it is recorded at the highest possible quality. To simplify this for everyone, all you need to know is, the higher the number, the better the quality. 

Music from a studio is normally produced at 24 bit. This is the level of quality which you would find on an HD  audio CD,  an HD DVD and a Blu ray disk.  At 24bit, a typical five minute song would be about 50 MB in size. This is the reason why an album encoded at this level will need about 5 GB of storage. The amount of processing per second  required by the player to play back this music in real time is also increased since more data is being processed within the same amount of time. This requires more power and as a result eliminates most portable music players.

Music is always compressed using smart algorithms which  strip out most of the information while at the same time keeping the song intact. As a result, it is scaled down to CD level which is 16 bit. Here a song is about 30 MB and an album is about 700 MB. CD quality music very good quality as this is what is intended for the listeners by the producers. 



Lossless audio formats


These are music formats which music can be converted to without losing any of the data. These formats maintain all the information within the audio file and are very large in size. Most common examples of such formats include Flac, Alac, Apple lossless and WMA lossless.

 High end portable players like Sony Walkman, Cowon music players, 2013 smartphones like the Galaxy Note 3 and LG G2 can play back lossless music at 24bit. iPod and older Android devices can play these formats at 16 bit currently.  Windows phone smartphones can play back 24 bit WMA lossless music. 




Lossy audio formats


These are the most common audio formats. They include MP3, AAC, AAC+, m4a, etc.. These formats are very compressed as most of the data has been stripped out.. 

Please not that 32 kb/s is not the same as 16 bit. In fact a 16 bit file is 1400 kb/s. This means that an MP3 is compressed to less than a 1/10 of the original file.

 For this reason MP3 files can be anywhere between 800 KB  (32 kb/s) to 10 MB (320 kb/s). You can imagine how much information has been pulled out in order to make the file that small. 



High end vs low end audio players.


Cowon Music player
Believe it or not but the exact same audio file at a given level of quality will sound tremendously different when being played in a different device. An mp3 at 320kb/s will sound so much better in a Cowon music player compared to your budget Android smartphone. This is why Sony's highest end Walkman will cost you almost $1000 and yet it's just a music player. The secret here is the sound processor that is embedded within the music player. This is also known as a DAC (Digital-to-Analog Converter ). The better the DAC, the better the music and of course the more expensive it costs.


Some portable devices like the iPhone and high end Androids offer an option for you to output a clean, un amplified audio signal to an external DAC. This will do the sound processing and give you way better sound than what the iPhone would have managed.
iPhone with FIIO external DAC



The Speakers and Headphones


Speakers or Headphones maybe the last piece of the puzzle but are very important. These will determine how music will be delivered to your ears. High end speakers will always sound better than low end speakers. This is the same case with head phones. 

Note that playing music via Bluetooth is lossy to some extent. Large files cannot be transferred over Bluetooth in real time. So stick to wires for a true audiophile experiences





Conclusion


If you are an audiophile and your ears are able to actually tell the difference between lossy and lossless audio, then you better invest in a high end Stereo of portable player. Stick to lossless music and you will blown away. Remember that sound is always produced in channels. It could be one channel i.e. mono, two channels i.e. stereo or 5 channels i.e.. 5.1 surround. S always position your speakers properly relative to your listening position.

If you have budget constraints, then you have to balance. Remember a cheap player will not only be unable to play back lossless audio but will also give you extremely distorted output with the lossy music. A mid tier player on the other hand can give you good results with a good set of speakers or headphones. 
and lastly avoid overly compressed MP3 files especially those that are less than 3MB iin size.