[linux-audio-user] Re: Companies Refusing to Release/Permit Linux Drivers - Linux-audio-user

26 Feb 2006

...
 Because no converter can reach even the 24bit
resolution. In fact the best 
...
 resolution you can reach is about 21 bits and the rest
three bit contains 
only a random thermal noise. 

regards,
Ctirad 
I did not know that - but am not really surprised.

...
 There are not any true 24bit a/d converters yet.
There are not even any true 22 bit a/d converters, perhaps in some labs.

I think the best converters in the world manage about 20bit. (120db
dynamic range.)

If a converter had a 24bit dynamic range (144db) and full scale was
+7db, then it would have to be able to resolve differences of 10
nano-volts (10 one billionths of a volt). That's perhaps possible with
cryogenics. Remember each extra bit *doubles* the dynamic range!

Real 24 bit recording should resolve from below the brownian noise floor
of air molecules hitting your ear drums to beyond the threshold of pain.

That's why we are stuck at 24bit 
Well thank you for a scientific explanation of this ceiling.
I guess, then, that *real* 24-bit resolution, or something very close to
it, would yield what I am looking for - if it can be achieved.

...
 Recording is about creating illusions, not fidelity. If
you record an
acoustic guitar in a totally dead room with the flattest most accurate
mic and pre, in to best a/ds in the world, it sounds... ok.
Put some reverb and top end on it, a little compression, perhaps add a
little distortion with an aural exiter, or recording to tape, and people
will say 'wow, what an amazing fidelity guitar recording!' :) 
I agree with this to a certain extent, but the quality of the effects - or
the final signal after the effects are added, is affected by the fidelity
of the original signal.
There is a huge difference in our guitar sound put through an 8-bit Zoom
processer, an 18-bit Alesis Q2, a 20-bit Alesis Q20, and a Behringer
"24"-bit V-Verb.
I think it is about both - using a high-fidelity acoustic signal blended
with creative, high-quality effects to create a beautiful auditory
experience.

...
 Bullshit. If you can hear the difference between a 20
bit converter
and a >20 bit one, what you hear is the difference between two
converters, regardless of the number of bits they use. 
And you can prove this?
I would assume, that if "24-bit" converters are really only 20-21 bits,
then a so-called "20-bit" converter is likely <<20 bit.
I maintain that I *can* hear bit-depth difference.
Are you perhaps suggesting that there exists some bit-depth threshold w/re
to human hearing?
What do you base your comment on?

...
 Even 16 bits correctly dithered is better than 24
tracks on a 2 inch tape. 
Again, what do you base this on?
Recording what?

"Correctly dithered" - and you would maintain that there is some objective
standard as to what constitutes this?
I can hear the distortion of the audio signal created by dithering, just as
I can hear the distortion of the audio signal created by Dolby - and I
don't like it.

If you think existing digital technology can already match or exceed the
audio fidelity of a 24-track reel-to-reel recorder, I would very much like
to know what it is, and where it is available - and I would like to hear
it.

-Maluvia