The essence of sound: The Faï’s Horns

The Place: its human and spatial context

The Ferme du Faï, perched at 3600 ft high on the mountains overlooking the

village of Saix (Hautes-Alpes, France,) sits on a slope opposite the cliff-face. Since

1963, the place is directed by the association “Le village des Jeunes” (a delegation of

Youth Solidarity) who organizes different kinds of voluntary works from environmental

.projects to various constructions. Besides its inhabitants, since the end of the 90s, it has

also been home to three rather odd-looking « horns », actually a gigantic sound

amplification system located out in the open air.

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Why the Horns? A short genesis

In 1991, Jacques Chataignier, who was the catalyst for the construction of the

horns and was later to be their future director, noticed that the site was gifted with a

natural suitability for echoes. Intrigued, he first tested a simple amplification system: he

directed two 50W speakers normally meant for personal use at the cliff.

From this first sound experiment, the project of constructing a sound system had

its beginning, one that was capable of making the most out of the acoustic property

provided by the location’s natural placement. Since then, the Faï’s “natural organ” has

become an essential ingredient in the region’s identity and its impressive “bass’ horn”

now its central attribute.

Thanks to the constant presence of “Village des Jeunes” volunteer works, the

construction began in 1991 – after three years of various experiments carried out with

the help of pre-existing audio systems - under the supervision of Michel Stievenart, the

sound engineer, who drew the plans and oversaw the implementation of the High and

Medium frequency Horns, built during 1993.

In 1997, it was the Bass frequency Horn’s turn to see the light of day, finally

finishing the long-imagined system. The goal: to avoid sound dispersion and echo

superimposition as far as possible. Indeed, the first experimentations showed that it was

not only power, but also directionality (gradient, location, direction) of the sound that

had a crucial part to play in the final quality of the listening.

What can it be used for?

The sound made by the Horns is not meant to be listened directly, instead it is to

be listened to through its echoes (distance from horns-cliff: 2625 ft i.e. time: roughly

2s, 2 to 5 secondary echoes bouncing off the 297 acres of the cliff’s face, three main

places for listening). According to the observations made by Pierre Jacques, the acoustic

engineer, the horns are suitable for music with slow tempo (requiring long enough

intervals between transitory sounds). Therefore the music styles that are most

appropriate are listed below: movie soundtracks, operating singing, experimental

music, sound design, certain classical music pieces, etc. All the equipment needed for

live music use is also available.

Who’s who? Project’s operators

Michel Stievenart: engineer

Jacques Chataignier : manager of implementation

Village des jeunes : building

Jean-Michel Pillone : Ferme du Faï’s director, sound and lights technician

René Dupré : audiophile, renovation

Pierre Jacques: acoustician engineer, report project

Queyras Libre: 3D modelling

The final four operators have provided the following data:

The physical features of the sound system, operational since 1998

[Data from Pierre Jacque’s research report (2011) and Jean-Michel Pillone]

High frequency Horn : 4 x Rad Motor 950 PB , features below

Bandwidth: 500 Hz – 20KHz

Electrical power allowance: 100 watts RMS

Sensitivity: 111dB

Nominal impedance: 8 or 16 ohms

Medium frequency Horn : 4 x speakers RCF L12 S 110 KP

Bandwidth: 60 Hz- 2000Hz

Electrical power allowance: 500 watts RMS

Sensitivity: 101 dB

Nominal impedance: 8 ohms

Bass frequency Horn : 12 x speakers RCF L15 S800

Bandwidth: 40 Hz- 1500 Hz

Electrical power allowance: 700 watts RMS

Sensitivity: 99, 5 dB

Nominal impedance: 8 ohms

These three horns are managed from the sound control which is comprised of:

- 2 CD players (5 CDs loadable)

- a mixing table YAMAHA MX 12/4 (12 inputs, 4 bus)

- a “homemade” filter, equipped with a symmetrical input with plug XLR 3 pins and 3

symmetrical outputs with plug XLR3 pins (sound distribution in three band frequency),

and a potentiometer with an input level and a 3 positions cut frequency selector. When

using the system in the “three horns” set up, the cut medium/bass frequency control is

180Hz.

- 2 amp Chevin Research A2000 2 channels: The first amp’s channel A supplies the

High frequency horn’s 4 speakers 16ohms, connected in parallel to the amp, which

gives a global impedance of 4 ohms. In this impedance, the amp supplies 800watts

power. The first amp’s channel B supplies the Bass frequency horn’s twelve speakers,

which are connected to the amp in 4 parallel groups of 3 in series, providing a global

impedance of 2 ohms. The second amp’s two channels are reserved for the Medium

frequency horn speakers.

- A bass frequency signals generator, brand Centrad GF 763AF. Can be used to carry

out either potential tests or calibrations.

H.freq Horn-2012 M. and H.freq. Horns after renovation-2013

Outlook from the B.freq. Horn- 2012

Created by Agnès André/Joon Kim