Rango dinamico

[AudioLuthier 758]

Hace tiempo encontre esta info, la acabo de reencotrar asi es que la comparto con quien desee instruirse.


""To master dynamic range compression we must first define what dynamic range in audio is, and secondly how we measure it.
We will see how better technology has allowed us greater dynamic range in recordings, but also question if there is any point. We will start at the fundamentals, later we will see how it relates to topics like the ‘loudness war’ and making great mixes.
What Is The Dynamic Range Of Human Hearing?
We have evolved to be able to hear a certain range of volume from very quiet to very loud. The dynamic range of our hearing is the difference between the quietest sounds we can hear (the threshold of hearing) and the sounds that are so loud that they cause pain (the threshold of pain).
How Do We Measure The Dynamic Range Of Human Hearing?
We measure it in decibels (dB). The threshold of human hearing is measured as 0dB SPL (sound pressure level) and the threshold of pain 120dB SPL. Therefore the dynamic range is 120dB.
The decibel (dB) is a logarithmic unit. I will skip the maths here, but basically in terms of power, 120dB is about 1,000,000,000,000 times more powerful than 0dB. That is a very wide range of volume for you to enjoy.
What Is The Possible Dynamic Range Of Recorded Music?
The dynamic range of a recording medium (such as a sound card or tape) is the difference between the loudest sound that can be recorded without distortion, and the quietest sound that can be recorded without disappearing into background noise. In the days of tape this background noise was the hiss of the tape, nowadays in digital it is the amount of bits we have available to record.
Here are some approximate dynamic ranges of different recording mediums:


[b]78 RPM Phonograph Discs
= 40 dB quickly reduced to 30 dB
and worse due to wear

Compact Cassette
= 50 dB

16 Bit Audio = 96 dB
24 Bit Audio = 144 dB[/b]


What Is the Useful Dynamic Range Of Recorded Music?
Here are some approximate dynamic ranges of different styles of music performed live:

[b]Symphony orchestra – 50dB
Chamber music – 30dB
Rock band – 20dB[/b]

If we are to make our recorded music the most enjoyable for the most listeners we have to take into account with what equipment and where they are likely to be playing back the music. Let us assume it will be in an average domestic environment with 40dBA background noise [1] (the A in dBA is a special type of dB measurement that takes into account the ear is more sensitive at mid frequencies).

We will also assume the max volume they are going to play the music is at 100dBA, that’s loud.

100dBa (max volume) – 40dBA (background noise) = Dynamic Range of 60dB

We are now down to the average Hi-Fi listener only being able to hear 60dB dynamic range, but its lower than that! Having the most quiet parts of the music at the threshold of their hearing is not going to be fun, its going to be a struggle to listen.

We can make the following generalisation for the scope of the article:

A useful dynamic range for recorded music for the average listener is 30dB

[b]So we are right back at the usable dynamic range of worn 78 rpm vinyl [/b]

Why Is Dynamic Range A Good Thing In Recorded Music?

If a piece of music is the same loud volume all the way through, is it really loud at-all? If there are no quiet parts, then how can we define the loud parts? Often a chorus naturally wants to be louder than a verse to give it impact. Going from a whisper to a scream requires a large dynamic range. When we create and produce music we can use the dynamic range to aid musical expression. We can have gently plucked guitars and booming techno bass lines all in one song
.
So What Exactly Is Dynamic Range Compression?

Now we understand exactly what dynamic range is, we can very easily answer the question what is dynamic range compression. It is simply making the difference between the quietest and the loudest parts less. This is done for many different reasons, including:
- To make a recording sound louder by reducing its loudest sections, thus increasing the volume of the quiet sections (in mastering).
- To make individual elements in a recording stay at a more constant volume, for instance compressing a dynamic vocal so the quiet parts are not lost under the rest of the mix and the loud parts don’t leap out (in mixing).

Conclusion

The human ear is an amazingly delicate device, it can hear a huge range of volumes from the wind gently rustling in the trees to an exploding bomb.
[color="#FF0000"][size="5"]With today’s recording and playback technology we have more dynamic range available than we can ever use.[/size][/color]

[b]We have had 96dB of dynamic range available since the 80′s with CD.[/b]

Earlier we demonstrated that [color="#FF0000"][size="5"]the maximum range the average listener could hear was about 60dB[/size][/color], and would actually ever want was 30dB.

[color="#FF0000"][size="5"]Very little recorded music today has 30dB of dynamic range.[/size][/color]

Many modern styles of music don’t require that much. Often dynamic range is reduced too much in mastering, this is the dark side of dynamic range compression and resulted in ‘the loudness war’.""

Editado August 2, 2013 at 05:50 por AudioLuthier

[Patagonia 739]

Ta interesante pero me suena raro los níveles que poner para música en vivo, siempre he leído cosas entre 50 y 120 db, de hecho búsqueda rápida en google me lleva a esos valores también.

Respecto al nivel de ruido, me parece interesante el concepto y es verdad que a veces hasta moverse en el sillón te puede enmasacarar algunos sonidos pero 40 db también lo encuentro alto para una escucha dedidada, en la casa al menos con el Ipad me marca entre 22 y 30 db cuando escucho pero si, incluso cuando se despeja la garaganta los 22 se mueven y cuando uno escucha de esa manera el volumen no lo sube tanto y no creo nica llegue a los 100 db entonces los 50-60 audíbles en la práctica tienen sentido...

[lnx 37]

Ahi esta la fuente, es de Octubre de 2012.

http://www.learndigitalaudio.com/blog/dynamic-range-compression-pt-1-what-is-dynamic-range

[charly 20]

Esto va de la mano con la distorsion, o sea, la claridad, o capacidad de resolver detalle.

En ese sentido para mi pasar de parlantes a drivers de compresion ha sido un salto enorme, en dinamica y detalle...

[Patagonia 739]

otro punto, cuántos db sobre el promedio de un tema puede tener algún detalle puntual como un golpe de batería, un trompetazo, grito etc...10, 20 db? si quieres poder tener la posibilidad de que realmente se tienan como deben tienes que dejar esos 20 db disponibles y si solo tienes 60 ya te quedan 40 para la escucha normal...yo creo que se necesita más...

Editado August 4, 2013 at 01:23 por Patagonia

[charly 20]

Yo de numerous no cacho, pero si creo que se necesita mas...
En mi experiencia Los problemas de dinamics se pueden manifestar cuando un parlante comprime, o un amplificador. Los pasajes intensos suenan, pero saturados, con un techo. Cuando logras escuchar un sistema que no comprime logras ver la diferencia de algo que explota sin sentirse exigido, ni sucio.

[MarkB 0]

Vengo a aclarar, el rango dinámico es definido en funcion de una resta por lo que el noise floor seria el minimo nivel y el peak el maximo. El rango es peak - floor.

Ejemplo THX reference level = 85 db con 20 db headroomm, eetonces Max = 115 db, min = noise floor = 40? db
Rango dinamico efectivo del THX = 65db. Suena correcto con lo del articulo.

En un concierto en vivo de musica clasica dificilmente se consiguen 40db de silencio, y a menos que sea una obra para gran orquesta, raramente alcanza los 90db. Si es con instrumentos de periodo es menos el sonido aun. Generalmente las orquesta de periodo tocan o con apoyo electrico o en salas de camara.

Eso ademas va a favor del argumento de que 16 bit son mas que suficientes para el repertorio musical en incluyen un buen colchón de reserva.

[lag 506]

[quote name='MarkB' date='21 September 2013 - 05:46 PM' timestamp='1379803568' post='213361']
Vengo a aclarar, el rango dinámico es definido en funcion de una resta por lo que el noise floor seria el minimo nivel y el peak el maximo. El rango es peak - floor.


[/quote]

Exacto , el rango dinámico es una cosa distinta al SPL ,
El rango dinámico está entre lo más fuerte y lo más sútil ( diferencia en dB) que un sistema puede reproducir a la vez sin distorsiones. .

De hecho un sistema con un rango dinámico de 60dB , puede perfectamente dar 120dB de un cañonazo de la 1812. Son cosas diistinas

Editado September 22, 2013 at 02:15 por lag

[charly 20]

Por eso es importante bajar el ruido del sistema, mejoras inmediatamente tu rango dinamico, que es una cualidad super importante para escuchar bien.
En general siempre se puede mejorar el esquema de volumen de fuentes digitales, pres y power para buscar una mejor relacion de atenuaciones.
(los volumenes atenuan, no amplifican)
Un atenuador bien puesto ha arreglado en mi caso problemas con oarlantes muy sensibles y controles de volumen digital ruidosos.

Editado September 22, 2013 at 02:59 por charly