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Headline of the month Monitors are not "true" ! Discover why with Patrick Thévenot of INA Did you ever bother about the difference between the "real sound"(music you are listening at in the studio or concert hall) and what you hear on your reproduction system ? It was studied scientifically. Things started in the middle of the 80's at Electroacoutics research laboratory of INA Patrick Thevenot, in charge of this lab, tells his management he wants to study and measure the listening phenomenon in the sound recording process.   About this subject: see in Archives page his technical article about the room influence on the monitor listening process On the ground of previous studies, this new piece of work led Patrick Thévenot and Bernard Torossian to the setting up in the early 90's of a very neutral and accurate Monitoring Studio loudspeaker, the 5025. In 1992, this Professionnal Monitor being successful, the two designers founded their own company A2T (the logo is the result of the two T's of Thevenot and Torossian) in order to bring their products to the market.

We will try to summarize and explain the scientific grounds used by these designers.You will find more complete explanations in the technical and press articles avalaible on this site.

First you have to know that all the parameters used in designing a "conventional" loudspeaker system are the same , but some of them are in a specific way and that will do the hearing difference.

* The frequency range is obviously very important, but most fondamental are:
- the phase response curve function of the directivity
- distorsion
- acoustical energy flowing speed function of time

* The physical coupling of the loudspeaker with the listening room is a major problem for the designer.
Two different cases may be considered:
- below 200 Hertz, the room influence, due to the great wave lengths, doesn't allow to make any difference between the frequencies generated by the loudspeaker and those coming from the walls reflections. This physical coupling may cause a very linear loudspeaker to become totally unsteady in terms of frequency response curve, due to phase cancellations caused by walls reflections.

* Between 200 Hertz and 20 Khz, the sound generated by the loudspeaker will not vary, but the room will nevertheless change the global audible perception of it: this is the psychoacoustical coupling. First listening room reflections (under the 10 milliseconds time limit) will merge with the direct sound coming from the loudspeaker.

"...you can have with the A2T a never heard accuracy, the reproduction of sounds you did'nt notice before using other brand's monitors.The traditionnal and inevitable "listening point" for stereophony becomes a large and steady listening zone. The three dimensional feeling is a real thrill. The listening result smashes to the ears ! "
(Home studio/1999)

A2T presented in 1994 a revolutionnary Sound Reproduction System :

PROSODIA ....