This system is to associate two speakers in series or in parallel depending on the impedances, and load them differently by two resonators of Helmotz.
The two speakers must have different resonant frequency and the two resonators are aligned on those frequencies.
Simultaneous operation of these speakers by a serie connection of their coil provides exceptional bass reproduction.
This system has the advantage of delivering a high serie level and easily reach 91 dB of sound level for 1 W at 1 m with conventional sensitivity speakers (88-90 dB).
• Input impedance : 4 Ω
• Rated power : 150 W
• Maximum power : 300 W
• Sensitivity (for 1 W at 1 m) : 90 dB
• Rated frequency range : 20 to 25 000 Hz
• Cutoff frequencies : 80 - 400 - 10 000 Hz
- Tweeter : dome 26 mm VIFA - D26TG modified by 3A
Art & Acoustique Appliquée
3A patent filed June 7, 1972 n° 72 20 413