Article idea?

[almaatakz]

Hello,

 

I recently thought it woulf be good to see a graph of a sine wave of different frequencies as it looks in digital format and after it is converted to analog, at different bit resolution and samling rates. For example:

 

Clean sine wave (one wavelenght), fixed level, fixed vertical axis scale, logarythmic horisontal axis (so we alwasy wee one wavelength)

1.a. 30Hz

1.b. 1kHz and

1.c. 15kHz

 

Same wave encoded to digital @ 16bit/44.1kHz (dots or line):

2.a.

2.b.

2.c.

 

Same wave @ 24/44.1 kHz

3.a

3.b.

3.c.

 

Same @ 24/96 kHz

3.a

3.b.

3.c.

 

Same wave (one wavelength) after digital/analog conversion

 

16/44.1

4.a.

4.b.

4.c.

 

24/44.1 kHz

5.a

5.b.

5.c.

 

24/96 kHz

6.a

6.b.

6.c.

 

Very geeky, certainly, but I think visual perception of this graphical representation of digital resolution should correlate well with acoustical perception of the resulting sound.

 

Would it be an interesting illustration to the hi-res music proposition or maybe a subject of a small article?

 

WDYT?

 

 

[Mahesh]

I might be totally wrong here, but doesn't Nyquist Theorem tell us that a band limited waveform, such as a sine wave, can be exactly reconstructed when the sampling rate is at least twice the frequency of the waveform?

 

If so, then for the sine waves you listed, going any higher than 44.1 kHz will not contribute to higher resolution in the sampled signal.

 

But still, I guess 16 vs. 24 bits might be an interesting comparison.

 

Mahesh

 

[almaatakz]

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I might be totally wrong here, but doesn't Nyquist Theorem tell us that a band limited waveform, such as a sine wave, can be exactly reconstructed when the sampling rate is at least twice the frequency of the waveform?

-----------

 

Right or wrong, what would be good is to see graphically (i.e. very simply and accessibly) where there is/should be gain and where there is/shoud be not.

 

If sine is too simple to show anyhting, maybe another form can be used that is more illustrative.

 

[bdiament]

Hi almaatakz,

 

This could be much more informative with the use of square waves, which, it could be argued, more closely represent what a music signal would look like.

 

I remember my shock the first time I put a square wave sweep through a Sony 1630 (back in the '80s), while I looked at the output of the converters on a 'scope. Somewhere around 7k and up, the scope started showing sine waves!

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com