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presentation d'une alternative aux compressions
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mastro
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RE: presentation d'une alternative aux compressions

il serait très intéressant d'avoir une traduction de cet extrait très intéressant du célèbre acousticien Philip Newell qui évoque l'isolation phonique dans une fameuse boite (à réverbération) dans la boite :


The main means by which we achieve the necessary sound isolation in recording rooms is by
reflexion, because absorption, as a means of isolation, is rather disastrously inefficient. In
typical isolation shells, the sounds produced within the rooms are reflected back from the
boundaries, and thus contained within the space. Sounds emanating from without the room are
similarly reflected back whence they came, and thus little sound can penetrate the isolation
barrier from one side or the other.
Reflective isolation from exterior noises presents no problems, but this method of
isolation to the exterior, by the concentration of the acoustic energy inside the room,
means that in the extreme we are creating a reverberation chamber. This only serves to
make the job of acoustically controlling the room much more difficult than it would
have been in its less isolated original state, where much of the sound could leak out. This
is especially so at low frequencies. In fact, one reason why so many domestic hi-fi
systems sound better in people’s homes than the monitor systems in some badly designed
control rooms has its roots in the relative degrees of isolation. Very often, the domestic
constructions are of a much more leaky nature for low frequencies. Much of the energy
escapes not only through the doors and windows but also through the structure of the
buildings. This means that it is easier to achieve a more flat, controlled response in most
domestic rooms than within the isolation shell of a simple control room, even though
musical acoustics never enter the head of most domestic architects. If we start off with
a highly reverberant shell, then the control measures must be much more drastic (and
proportionally more expensive) than if we begin in a normal domestic room, where the
reflected low frequencies are not so concentrated.


page 85 , Recording Studio Design (Philip Newell)

http://library.momraths.com/ebooks/Phili...Newell.pdf



autre texte intéressant page 666 :

From an internal acoustics point of view, a lightweight, well-damped shell is desirable, as the whole surface area of three walls and a ceiling can be used for absorption.
If some of the very low frequencies are allowed to re-radiate into the outside air, it effectively makes the room acoustically much bigger at low frequencies than it is physically. Remember, at around 30 Hz the threshold of hearing is about 65 dB SPL. Five to ten decibels up on this would be the minimum level that could provoke complaints in most countries, so only 20 dB of isolation at those frequencies would still allow monitoring at 95 dB SPL with impunity



https://livre.fnac.com/a3780303/Philip-N...4a38db4be9




Ce message a été modifié le: 30/07/2019 09:47:40 par mastro.

30/07/2019 09:40:19
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RE: presentation d'une alternative aux compressions - mastro - 30/07/2019 09:40:19

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