JM Reynaud Orfeo Grande

Just arrived! The amazing Orfeo Grande

WOODWORKING:
Device limiting the phenomena of solidian transmission of the vibratory energy thanks to the use of materials of different density (MDF-Aluminium). A 3 mm thick aluminum sheet encloses three sides of the cabinet to better concentrate the energy towards the interior of the acoustic load.
Loading principle: Tuned triangular line in ¼ wave leading to a front vent located at the bottom of the cabinet. This proprietary loading principle allows us to use almost no sorbent that would slow down the air flow in the different cavities. Thus, the signal propagation speed is much faster and the group propagation time of the system is greatly improved. In order to better control the vibratory phenomena, we have lined a large part of the internal surfaces of the cabinet with bitumen and viscoelastic compound positioned in an experimental manner at strategic points.
Complete mechanical decoupling of the enclosure base, allowing the use of Teflon pads as interfaces with the floor (no decoupling spikes). The speaker is as if suspended. Thus, the vibratory energy is transformed into heat within the polymer and is hardly transmitted to the ground. The result is a perfectly controlled bass that integrates with the musical message in a much more natural way since it never vibrates the floor material. The other advantage is to preserve the middle part of the signal without the drying phenomena often observed when using rigid decoupling tips.
LOUDSPEAKERS :
TWEETER :
AST type tweeter (aerostriction) :
It consists of a pleated diaphragm 25 mm wide by 60 mm high, whose silicone support is covered with a very thin film of extremely light avionics-type aluminum. This diaphragm is traversed by an aluminum greek and the whole is surrounded by two neodymium bars of very strong power. Its operating principle is the same as that of the Heil or AMT transformer, but it has the particularity of using a diaphragm that is perfectly devoid of its own resonance. Contrary to a classic ribbon tweeter which pushes the air in front of it, the aerostriction tweeter pinches the air between its folds and expels it with a very high velocity, the dynamics is thus much greater (on the big gaps of level as on the very small nuances).
BOOMER/MEDIUM :
Medium/boomer 180 mm
Its cone is made of 7 layers of carbon fiber and PEEK (Polyetheretherketone). This cone receives a plasma treatment on its external surface (granular) which avoids the formation of surface standing waves. This cone combines great lightness with good rigidity, but above all excellent internal damping.
This cone is driven by a 37 mm coil on two 16 mm long layers on a ventilated fiberglass support.
The air gap has a pure copper ring to linearize the impedance of the loudspeaker at the end of the band and to reduce its distortion by improving the concentration of the magnetic flux around the coil.
Its speeder is airy and has a progressive profile to allow a movement with a constant return force whatever the amplitude of its movement.
The NBR rubber suspensions have an optimized profile in terms of their curvature in order to obtain a progressive splitting and to maximize the efficiency of the return according to the distance of displacement of the mobile equipment.
These loudspeakers are tensioned as usual, thanks to stainless steel threaded rods that come to push the breech of the speaker and are tensioned on the back wall of the cabinet. This principle brings the mechanical reference of the loudspeaker to the back of the cabinet and ensures a better distribution of mechanical stress on the front of the cabinet. It improves the transient operation of the HP by stabilizing its mechanical reference. This results in a midrange that is free of all distortions related to the micro-displacement of the speaker motor and a much faster and better damped impulse response.
FILTERING:
• The passive filter :
It has been completely redesigned with different connection frequencies and the best components currently available on the market.
As usual, I wanted to reduce the number of these components as much as possible in order to obtain a speaker easy to feed.
No resonant circuit or plug circuit. Only the components necessary for the realization of the 6/12/12 dB/octave filtering are used.
This is a 2.5 way configuration, with the two bass-midrange speakers working in tandem and in phase below 200 hz or the bass speaker is connected in 6db/octave. The top speaker is dedicated to the mid/bass and is connected at 2200 hz with the tweeter and is not filtered in the bass.
This filter consists of two separate cells, oriented and separated from each other to avoid intermodulation of components.
The equalization resistors for the tweeter are of a very high quality, they are wound and have the particularity to be surrounded by a copper tube connected to the ground of the system. (They have three wires, input, output and ground and must be oriented in the direction of signal flow) the whole is then trapped in an inert resin. This copper tube acts as a shield (Faraday cage) and eliminates all electromagnetic disturbances around the component which are evacuated by the system ground, but also acts as an excellent heat sink. Thus, the distortion rate of this resistor is particularly low. A ground braid is then connected to the terminal block of the speaker on a fifth terminal which is then connected to the ground of the domestic electrical installation. This completely drains all electrostatic and electrical charge and cleans up the signal for a more relaxing and detailed listening experience.
As usual, all the filters are made by hand, without using a printed circuit. The components are soldered directly to each other using ROHS silver solder and are attached with a flexible adhesive to forex plates that further isolate the components from vibration.
The two cells are arranged as far as possible from the magnetic radiation of the loudspeakers and are themselves acoustically shielded with compound and foam.
All the internal wiring is done with a new cable reference that uses some elements of our HP1132 cable but in a slightly different configuration since it has a star structure. The silver-plated copper core has a large cross-section and is then surrounded by small cross-section strands, still in silver-plated copper.
Chaque composant est mesuré et trié par paire avec une tolérance de 1%. Thus the crossover components have perfectly identical values on the pair of speakers
The connection of the loudspeakers is entrusted to ETI terminals (the same as those used on VOCE Grande) which have been extensively compared and selected for their exemplary musicality. They are made of silver-plated tellurium copper of very low thickness providing an extremely low internal resistance. They are fixed on a bituminous aluminium plate