This is an analog sound wave.
This is a digital sound wave.
Now this is a crude example of what happens in a process called sampling. When sampling occurs, small 'samples' of the sound wave are used to represent a larger portion of the wave. Sample rates are measured in Hertz (Hz, cycles per second). In other words, it is how many times the sound wave is split into smaller 'samples' per second to represent the whole sound wave. So the higher the sample rate of a digital recording, the closer that digital sound wave will be to that of the original sound. A familiar example would be that the sampling rate for CDs is 44.1kHz, meaning the sound has been sampled 44,100 times per second. DVDs have an audio sample rate of 48kHz, giving them a higher resolution sound.
Sound can never be truly represented in a digital recording, but sampling isn't the only process that diminishes sound quality. A process called anti-aliasing also occurs with digital sound. Anti-aliasing minimizes distortion artifacts when representing a high resolution signal at a lower resolution. This process is not only used in digital audio, but also with digital photography and computer graphics. in a sense, this process 'smooths' the edges. When this happens in digital audio, many frequencies of the natural sound are lost.
The human hearing range is from 20Hz to 20,000Hz. Even though most of the frequencies filtered out in the process are outside of the human range, they include harmonic frequencies within our range. It is these frequencies that add the 'warmth' that is commonly referred to with analog sound.
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So, what do you recommend for an incredible listening experience? (Suggestion for a new post)
ReplyDeleteWow I love the look of your blog! And the content is interesting too, I wasn't aware that sound can be so distorted by the recording process in this digital age. Anti-Aliasing is a term I am familiar with because of my gaming background. However, in video games anti-aliasing is used for increased visual fidelity. Anyways, I am blogging about terrible music of the past so this blog is a welcome compliment to mine. Looking forward to more lessons; keep up the good work.
ReplyDeleteThis is something that has always bothered me but I didn't know there was an actual known reason for it. It seams that whenever I play on my acoustic guitar the sound has more warmth and tonality than when I play back a recording of myself playing on the same instrument. I wonder how this effects the way an electric guitar works. Are the infinite little tones lost when the sound is amplified or are they still there?
ReplyDeleteThis was very interesting to me. I know that some music sounds better than others, and depending on the source, it may seem richer with no real explanation, be it the radio, my car stereo, my PC speakers. Is that these effects, or is it due to the quality of the speakers and reproduction system perhaps?
ReplyDeleteI have found, using Pro Tools, that digital music has a terrible time translating distortion. When I needed to record distortion, I would always start by getting it on analogue and then transferring the analogue to digital--but then this caused trouble.
ReplyDeletePerhaps the software and technology is getting better, its been a few years since I played with this stuff.