Re: Advantage of tape over MD?

[Bob Cain]

Lord Hasenpfeffer wrote:
>
> Understanding how to use the software to achieve desired results and
> understanding the jargon used to describe the process are not
> necessarily interdependent requirements of the experience overall.

Unless you wish to communicate about it with others.
>
> Onion other hand, there's a good chance that I already do understand
> what "RMS" is without actually recognizing the acronym. What exactly do
> the letters represent?

Root Mean Square. If you square every sample in the file,
add all those numbers up, divide by the number of samples
and take the square root you get the RMS of the file. It is
a measure of its overall loudness. -12 dB is pretty hot.

>
> I honestly think the reason why the older CDs sound as bad as they do is
> because audio processing software such as "normalize" hadn't been
> invented yet at the time they were manufactured.
>

If you think that louder is better. The process of
squeezing the dynamics of the music to get that extra
loudness introduces distortion (which may actually "enhance"
some kinds of music to some listeners) and generally makes
it less interesting. There is a growing sentiment among
recording professionals that it is exactly this process of
squeezing the dynamics for the sake of loudness that is
making music less and less interesting and faithful to what
was recorded and there is a growing movement away from it.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Geoff Wood]

"Lord Hasenpfeffer" > wrote in message
..
>
> dB or dBFS?

dB is a relative term, and by itself means nothing.

dBFS is decibels relative to a real figure, relating to the analogue level
represented by a digital word at "all 1's" .

dBV, dBM, and dBU are other varieties of dBs refernced to a specific actual
voltage/power.

Read a book.

geoff

[Lord Hasenpfeffer]

I can see you're growing as tired of this as I am, so I'll make this brief.

Geoff Wood wrote:

> dB is a relative term, and by itself means nothing.

Correct.

> dBFS is decibels relative to a real figure, relating to the analogue level
> represented by a digital word at "all 1's".

Relative to the analogue levels of "all bits on" which is
1111111111111111 or 111111111111111111111111
depending on whether you're using 16-bit or 24-bit resolution.
No problem there.

I think my last question at this time, then, is this:

If the WAV of a sine wave was normalized (i.e. maximum peak just below
0dB, no clipping) and the "level" of that WAV was -12dBFS, would the
bisector (i.e. the average level) of the sine wave be located 12
decibels below 0dB?

Myke

[Geoff Wood]

"Lord Hasenpfeffer" > wrote in message

> If the WAV of a sine wave was normalized (i.e. maximum peak just below
> 0dB, no clipping) and the "level" of that WAV was -12dBFS, would the
> bisector (i.e. the average level) of the sine wave be located 12
> decibels below 0dB?

Maybe something like -12dB, yes. But specify 'average level', because the
'level' is ~0dB.

geoff

[Bob Cain]

Lord Hasenpfeffer wrote:
>
>
> If the WAV of a sine wave was normalized (i.e. maximum peak just below
> 0dB, no clipping) and the "level" of that WAV was -12dBFS,

Here's were what dB is relative to begins to come into the
picture. A sin wave that is normalized is defined as 0 dBFS
(usually.) To clarify (or perhaps confuse) things, if you
consider full digital scale to be +/- 1.0 and do the RMS
calculation I mentioned on that normalized sin you will get
a value of .707 (sqrt(2)/2). This means that dBFS is the
average RMS value of the signal relative to .707. I.e.,
considering samples to have the range +/- 1, square all
their values, take the average and then take the square root
of that. Call that number N. Then the level of the file in
dBFS would be:

20*log10(N/.707)

If a signal is -12 dBFS (averaged over its whole length)
then you can go backwards to the to its average RMS level
as:

(10^(-12/20))*.707 -> .1776

dB is always 20 times log base 10 of the ratio of two
things. The thing on the bottom is what it is relative to.
dBu for example is voltage relative to .775 V (for
historical reasons). dBV is voltage relative to 1 V. dBA
is sound pressure relative to 2E-5 Pascals.

> would the
> bisector (i.e. the average level) of the sine wave be located 12
> decibels below 0dB?

The average level of a sin is zero and zero is -inf dB. Now
you are thinking about instantaneous rather than average RMS
values. An instantaneous level that is 12 dB below another
is 1/4 of the other. Confused yet? :-)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein