Leonardo speakers Technology
The design of our transducers has always been based on the ribbon technology. The pure ribbon is just a ribbon almost completely covered with conductor, clamped at the two ends and free at the sides. This design is ideal to minimize distortion at middle-high frequencies but it is not suitable for low frequencies as the surface is limited to some hundred square centimetres and the excursion associated with the low frequencies reproduced by a woofer would be very big.
To make the low frequency transducer we basically use the same technology to make the diaphragm, but this time we are using the ribbon-planar design, which means that the conductor is a lightweight aluminium foil laminated to a thin plastic diaphragm which in this case extends beyond the surface covered by the conductor and is tensioned over the 4 sides to give stiffness and reduce the excursion making physically possible the reproduction of low frequencies otherwise impossible with the true ribbon design.
We have decided to use the push-pull technology, not very common in planar woofer design, to have the same sensitivity as the true ribbon used for the higher frequencies and to have lower distortion related to magnetic field non-linearity.
The push-pull design is made with magnets on both sides of the diaphragm, simmetrically positioned, so they are in opposition (S pole in front of S pole and N pole in front of N pole). This technical solution reflects on the unconventional design of a see-through metal grid that acts both as magnetic field closure and front grid to avoid touching the diaphragm with fingers. We are now making a full range ribbon loudspeaker, uniquely showing sensitivity of 93dB (Effective) and making it possible to use low power single ended triode amplifiers with a full range planar speaker. We have good experience with 5Watt amplifiers in relatively small rooms (15 square meters = 150 square feet), but of course you can get more sound pressure with higher power as there is no problem to use up to 250Watt.