Dynamic range question, Dynamic range of hearing vs. equipment Options

[thesurfingalien]

Hi All,

I am having problems understanding the concept of dynamic range, and more specific how the dynamic range of human hearing relates to the dynamic range as specified for audio equipment.

What I have read on the Net is that the dynamic range of human hearing is, on average, 135 dB (the pain limit / threshold?).

I also understand that the dynamic range of a CD (16 bit) is limited to 96 dB, and for HD (24 bit) recordings 144 dB. This dynamic range is calculated by the bit-depth.

For playback of music (I use 44.1/16 flac only) I use a E-MU 1820 that has a dynamic range of about 115 dB (or so). I am not sure what my amp can do...

However, when I play music I hardly pass 80 dB (or so) listening volume, so the 96 dB CD data (if the recording makes full use of the range that is) gets "compressed", while the relative dynamic range remains.

After the long intro my question in essence is:

Does the human hearing have a similar "resolution" that is comparable to the resolution defined by the bit-depth in (digital) audio? Or am I just comparing apples and pears?

Regards,
Peter

[Northpack]

I think this relation 1bit to 6.02dB is where some all-too-common misconceptions rely on. The most notorious: the digital-loathing audiophile who thinks than he can hear the "switching of the bits"... you know, those harsh digital steps in a PCM waveform who completely ruin the smooth analogue siginal.

So, if someone really wants to explain digital audio to the layman without proper mathematical knowledge, I think it would be best to start by debunking this very misconception, explaining why there isn't such a thing as an arbitrary step size in digital audio and how the dynamic range is limited by quantization noise.

Anyone interested in writing such an explanation? I think it could save hundreds of souls from ignorance... he or she would gain some Karma!

This post has been edited by Northpack: Jun 14 2011, 08:21

[knutinh]

I think this relation 1bit to 6.02dB is where some all-too-common misconceptions rely on. The most notorious: the digital-loathing audiophile who thinks than he can hear the "switching of the bits"... you know, those harsh digital steps in a PCM waveform who completely ruin the smooth analogue siginal.

So, if someone really wants to explain digital audio to the layman without proper mathematical knowledge, I think it would be best to start by debunking this very misconception, explaining why there isn't such a thing as an arbitrary step size in digital audio and how the dynamic range is limited by quantization noise.

Anyone interested in writing such an explanation? I think it could save hundreds of souls from ignorance... he or she would gain some Karma!

Properly dithered digital behaves similar to analog systems where the noise floor is (best case) about 6*#bits below the maximum signal.

For CD (16 bits) this works out to be about 96dB, or 2^16 or 65536:1. For hirez formats using 24 bits, this would ideally mean 144 dB, but in practice man cannot make AD and DA-converters of such high precision.

When doing proper level-aligned blind testing, somewhere around 14-16 bits seems to*) be enough for all sound playback applications. More resolution mainly buys you peace of mind.

-k
*)Blind tests cannot prove that any resolution is "high enough" for all applications, but it repeatedly failing to prove it is often considered a convicing indication.

This post has been edited by knutinh: Jun 14 2011, 09:14