When we wants that our voice carries far, we put our hands as funnel in front of the mouth. Thus we realise a pavilion.
The main interest of the pavilion is to improve the coupling with ambient air and thus efficiency. That is why they were used at the beginning of the sound reproduction with phonographs, when the amplifiers didn't exist. the vibration of the needle in the furrow directly make vibrate a small membrane and the beat is amplified by the pavilion.
Later the first amplifiers being very low power, pavilions remained essential for proper sound level.
The time of beginning of talking pictures was that of pavilions, to get sound in rooms of 1000 or 1500 seats with 10 or 20 W amplifiers only. Several pavilions shared the sonic spectrum of low to high. This is still the case for many sound installations for cinemas.
Today some sound systems are always equipped with pavilions, although more sophisticated techniques have emerged.
In high fidelity, except for a very small minority of fans who still use a complete system with several pavilions of low to high, there are only for the treble reproduction that they are still a little used. Often the acute motors (tweeters) are equipped with a pavilion that helps the spread of high frequencies, which are in nature more directional. The main advantage is the increased yield. They take a known principle of all, that of a megaphone. Without going into detail, this principle makes possible to make displace to a speaker's membrane a greater amount of air as its surface. The amount of air moved will be equal to the surface of the horn mouth, hence better yield (higher acoustic pressure). Besides the treble speakers, this principle is used by some speakers. We also see uses sono for improving the efficiency and control the directivity.
• Input impedance : 6 Ω
• Rated power : 100 W
• Sensitivity (for 1 W at 1 m) : 105 dB
• Rated frequency range : 25 to 25 000 Hz
• Cutoff frequencies : 800 - 3000 - 6000 Hz
- Tweeter : Compression chamber 50 mm FOSTER - FHT6
Caractéristiques
Unités
Valeurs
Puissance nominale
W
12
Puissance maximale
W
40
Bande passante
Hz
-
Niveau d'efficacité caractéristique
dB
-
Diamètre nominal hors tout
mm
-
Diamètre bobine mobile
mm
-
Diamètre ouverture baffle
mm
-
Introduction dans l'entrefer
gauss
-
Flux dans l'entrefer
Maxwells
-
Énergie magnétique du moteur
WS-1
-
Facteur de force
NA-1
-
Hauteur du bobinage
mm
-
Hauteur de l'entrefer
mm
-
Masse de l'aimant
g
-
Masse équipage mobile
g
-
Masse du haut parleur
g
-
Impédance nominale
Ω
8
Fréquence de résonance
Hz
-
Facteur de qualité mécanique
Qms
-
Facteur de qualité électrique
Qes
-
Facteur de qualité total
Qts
-
Compliance de la suspension
10-3 MN-1
-
Température max de bobine mobile
C
-
- Midrange : Compression chamber 5 x 12 cm FOSTER - FHT3
Art & Acoustique Appliquée
