October 12, 2024

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Demystifying Audio Formats: What Format Should You Record In?

Demystifying Audio Formats: What Format Should You Record In?

There are so many audio formats out there, which ones should you choose to record your audio in? An audio format is a file format through which music is stored on your computer. There are a wide variety of formats, like wav, mp3, aiff, wma etc. To understand the difference between various formats, we need to first understand terms compressed and uncompressed formats.

Uncompressed Audio Formats

Uncompressed audio formats are bulky files and take up considerable space on your hard disk or storage drive. The advantage of uncompressed audio formats is that the quality of the digital audio remains intact, as it is unchanged. It provides exactly the same quality; no matter how many times you process or re encode it.

Compressed Audio Format

Compressed audio formats compress the digital audio data, resulting in smaller files. You can free up valuable space on your hard disk by using compressed audio formats.

Compressed audio formats are further categorized into 2 two groups:

Lossless Compressed Audio Formats

These audio formats compress digital audio data, but there is no loss of data or degradation of audio quality during the compression process. The finest example of such format is flac.

Lossy Compressed Audio Formats

These audio formats compress digital audio data, but are known to eliminate certain information and frequencies to reduce the file size. lossy compressed audio formats causes degradation in audio quality. The difference in audio quality can be large or small, depending upon how much data has been removed. Also, each subsequent processing or re encoding will result in more quality loss. The classic example of lossy compression is MP3.

Which recording Format is the best for me?

To choose the best recording format, we need to understand 2 more terms, Sampling and bit rate. Digital audio has two primary qualities that compose the way the audio is described. – sampling rate and bit rate.

Sampling Rate

When you are recording audio digitally, the device (say, your computer) receives the audio signal, by breaking it up into “snapshots” or samples. In recording technology, the number of samples received per second is called the sampling rate. The concept is comparable to a digital movie camera that records a number of image frames per second and plays it back as a continuous moving image. Similarly, you listen to uninterrupted audio playback. Sampling rate is measured in hertz and represents the sound frequency range. Higher the sampling rate greater is the audio quality and ensures greater precision in your high notes and low notes. Standard CD quality incorporates a sampling rate of 44, 100Hz or 44.1 KHz. Sampling rates start from 8000hz(very low quality) to 196,000(very high quality, with extreme huge files).

Bit Rate

In digital multimedia, bit rate often refers to the number of bits used per unit of playback time to represent a continuous medium such as audio. Let us understand what the bit rate actually represents. While sampling rate is number of samples recorded per second, bit rate refers to the characteristics of each individual sample recorded. Going back to the digital camera example, bit rate is the equivalent of pixels in digital images. Higher the pixels, better is the image quality. Similarly, higher the bit rate (also called bit depth), better is the audio quality. For instance an 8 bit audio will sound grainy and harsh, while a 16 bit audio sounds much better. Standard CD format has 44.1k sampling rate combined with 16 bit rate.

Naturally a 24 bit audio will offer the highest quality, but such files occupy more space and require greater computing power to process and may not be really necessary for the purpose of your audio. For FM transmission or internet streaming 16 bit rates are perfect. Professional audio studios opt for 24 or 32 bit rates, because the higher accuracy it offers is useful in the recording, mixing and mastering process.

Bit Rate in MP3

The MP3 format is lossy audio format that compresses audio files to reduce size by eliminating redundant data. You can choose how much information an MP3 file will retain or lose during the encoding and compression process by tweaking the bit rate. Lower bit rate means that the encoder will discard more information during the compression process, which may affect the audio quality on playback. Bit rates for MP3 encoders range from 16 kilobytes per second (kbps) to 320 kbps. A bit rate of 320 kbps gives CD quality audio and is similar to what you’d hear on the radio. A higher MP3 bit rate provides better audio quality but produces larger files.

So what do you choose for recording your audio? For pristine quality, always record in uncompressed formats like wav or aiff, at atleast 44,100 khz and 16 bit. This has 2 advantages. First, the audio will be recorded in cd quality. Secondly any subsequent processing like mixing, editing etc will not result in any degradation of the quality. If you need to encode/record in mp3, at least 196kbps is minimum for a decent quality, though 320 kbps is always the best.

Some of the commonly used audio formats include the following:

1. WAV Format

The Wavform or wav audio format stores uncompressed audio data on Windows computers. It is based on the RIFF bit stream format method of storing data. Since it stores uncompressed audio data, it retains the 100% original audio quality and is popular amongst audio experts. The WAV format can be easily edited using software. (Always record in 44,100 Khz and 16 bit(minimum) for studio grade recordings)

2. AIFF Format

The Audio Interchange File Format (AIFF) developed by Apple Computers is an uncompressed audio format commonly used for storing audio data on Apple Macintosh systems. Because it stores uncompressed audio data, the AIFF format is also commonly used for professional audio applications. (Always record in 44,100 Khz and 16 bit (minimum) for studio grade recordings)

3. MP3 Format

The MP3 format is a commonly used lossy compression audio format. It essentially reduces the file size by omitting data in the file. By using perceptive audio coding and psychoacoustic compression, the MP3 format retains the quality as close to the original as possible. Therefore MP3 is the commonly used audio format for storing large number of songs on your computer without taking up too much space with acceptable quality. Never record in MP3, unless you have no other option. Always record in uncompressed formats like wav/aiff and THEN CONVERT to mp3 file of desired size.

4. AAC Format

The Advanced Audio Coding (AAC) format, another lossy compression audio format was developed to be the successor of the MP3, as it offers better audio quality than the MP3 at lower sizes. It is the standard audio format in Apple’s i-Tunes and i-pods.

5. WMA Format

The Windows Media Audio (WMA) format is a lossy compression audio format designed by Microsoft to compete against the MP3. However the MP3 stills retains the top spot in popularity. The lossless compressed version of the WMA format called WMA lossless is also available that reproduces the original audio quality, with zero elimination on decompression and play back, similar to wav or aiff.