JM Reynaud Orfeo Jubile
ACOUSTIC ENCLOSURE :
The proprietary acoustic loading to our creations has been redesigned its profile optimized but still remains a triangular transmission line tuned in wave ¼ leading to a frontal event port at the foot of the enclosure.
Thus, this new version of our triangular transmission line allows us to use practically no damping material in the line itself: only the partition wall is covered by a thin acoustic foam, and a crown of cellular foam acts as acoustic diode at the back of the cones of the drivers; no damping material impedes the air flow in the loading. Thus, the signal propagation speed in the line is much faster and the group delay of the system is greatly improved. In order to better control the vibratory phenomena, we lined a large part of the internal surfaces of the cabinetwork with bitumen and viscoelastic compound positioned experimentally at strategic points.
The tweeter is housed in a solid turned piece of wood that has been decoupled from the upper surface of the cabinet using a bitumen joint and fixed with specific silentblock.
The entire cabinetwork sits on a base which is itself decoupled by a viscoelastic compound joint and placed on adjustable spikes.
AST type tweeter (aerostriction) :
It consists of a pleated diaphragm 25mm wide by 60mm high, whose silicone support is covered with a very thin film of extremely light avionics type aluminum, this diaphragm is crossed by an aluminum wire and is surrounded by two very strong neodymium bars. Its principle of operation is the same as the Heil or AMT transformer, but it has the particularity of using a diaphragm that has no resonance of its own. Unlike AMTs using KAPTON for their diaphragms, this one is very smooth while being very informative and fast. Unlike a traditional 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 great velocity, the dynamics is thus much greater (on the large differences of level as on the very small nuances...).
It is not fragile, offers a very high-power handling and a distortion rate very clearly lower than that of the ribbon especially at the end of the band where its movements are the most important. It can therefore be used much lower in frequency than a ribbon while using a less steep crossover slope, moreover its impedance curve and perfectly straight and it has no marked resonance frequency. Finally, its horizontal directivity is extremely low. As it functions in dipole it is essential to associate a small closed loading behind it which it is necessary to tune in an experimental way and which is damped by an extremely aerated specific felt.
WOOFERS / MEDIUM:
These new 180mm drivers were developed in collaboration with a German company that only works on OEM products. We had already collaborated on the CANTABILE Jubilee tweeter which, for me, is probably the best textile dome tweeter I have ever heard.
It took almost a year and a half of work on several prototypes to finalize the study of this extremely powerful driver.
Its cone consists of 7 layers of carbon fibers and PEEK (Polyetheretherketone). This structure is particularly long and complex to achieve because each layer must be produced with a very precise drying time to allow the whole to be as homogeneous as possible. This cone receives a plasma treatment on its external surface (granular) which prevents stationary wave formation. This cone combines great lightness with good rigidity but above all excellent internal damping. The cone of a loudspeaker is a clever balance between rigidity and internal damping capacity to avoid resonances specific to the material used. On this particular point we have achieved particularly satisfactory results.
This cone is animated by a 37mm voice coil 16mm long winded on two layers with ventilated glass fiber support, this support receives a surface treatment in order to absorb the maximum its natural resonance frequency. A ring of plasma-treated material is placed on the coil carrier field again to prevent the coil carrier material from acoustically manifesting itself.
The air gap has a pure copper ring to linearize the impedance of the driver at the end of the band and to reduce its distortion by improving the magnetic flux concentration around the coil.
Its spider is aired and has a progressive profile in order to allow a displacement with a constant feedback force whatever the amplitude of its displacement.
This woofer has a double 100mm ferrite magnet with double control ring and has a very strong magnetic field.
The NBR rubber suspensions have an optimized curvature profile in order to obtain a progressive fractioning and maximize the recall efficiency according to the mobile moving part.
Its basket is made of aluminum and largely opens the back face of the cone.
Its core is pierced but receives a damping treatment consisting of several microphonic felt discs oriented.
A fabric dome dust cap impregnated with a specific treatment on its inner side covers the coil, it is glued to the cone using a latex-based glue.
These loudspeakers are tensioned as usual, thanks to stainless steel threaded rods which push theclamp of the driver and are tensioned on the back wall of the cabinet. This principle brings the mechanical reference of the speaker back to the rear of the enclosure and ensures a better distributed mechanical force on the front face of the cabinet. It improves the transient operation of the HP by stabilizing its mechanical reference. This results in a medium cleared of all distortions related to the micro displacement of the driver and a much faster and better damped impulse regime.
It has received a lot of attention and a very long period of optimization. During 6 months I compared and tried different configurations of crossovers but also different types and brands of components in order to retain only the best. These components are extremely qualitative and therefore particularly expensive. These tests were made with the measurement of course, but also and especially with listening in order to select those who, beyond what could show the laboratory work, showed themselves the most efficient with listening.
As usual I wanted to reduce the number of these components as much as possible in order to obtain a loudspeaker that was easy to drive. No resonant circuit or plug circuit. Only the components required for type 6/12/12db/octave crossover are used.
It is a 2.5 way configuration, both bass midrange drivers working in tandem and in phase below 400hz where the bass driver is connected in 6db/octave. The top driver is dedicated to the mid/low end and connects at 3500hz with the tweeter and is not filtered into the low frequency.
This filter consists of two distinct cells oriented and separated from each other in order to avoid intermodulation of the components as much as possible.
We use silver armature capacitors with HP1132 cable termination (silver/copper) The winding orientation is marked and they are specific to our use (manufactured under specifications by a French company S.C.R).
The coils are made of large dimension pure copper foils winded around a solid wood core and encapsulated in wax to prevent unwanted intermodulating radiation. These coils have the particularity of offering an extremely low distortion rate, a very low internal resistance and very high power-holding capacities. This results in a very full bass, articulated with a lot of density, substance and a great dynamics. They are used both on the bass but also for the connection of the medium with the tweeter.
They are orientated to each other to avoid unwanted radiation.
The resistors for the level-equalization of the tweeter are of the highest quality, they are wound and have the particularity of being surrounded by a copper tubing connected to the ground of the system (they thus comprise three wires, input output and ground and must be oriented in the direction of signal flow) the assembly is then confined in an inert resin. This copper tube acts as a shield (Faraday cage) and eliminates all electromagnetic interferences around the component that are evacuated by the ground of the system, but also acts as an excellent heat dissipater. Thus, the distortion rate of this resistance is particularly low. At large level variations, conventional resistors tend to heat up enormously, which results in distortion. With these resistances, the high frequency is very transparent (micro-discharge evacuation) and extremely dynamic with an amazing natural feeling, leaving room for all the micro information essential to a truly musical listening. The harmonic gradient is much more logical and devoid of "slag", the high frequency is smooth, fine, without persistence or undesirable granularity effect.
As usual, all the filters are made by hand, without using a printed circuit board, the components are soldered directly to each other using a silver ROHS solder and are fixed with a flexible adhesive on Forex plates which still isolate the components from vibrations.
All internal wiring is done with our HP1132 cable whose cross-section is doubled for midrange and low-end.
Each component is measured and sorted in pairs with a tolerance reduced to 1%. Thus, the filter components have perfectly identical values on the speaker pair.
The connection of the speakers is made using high-quality pure copper Mundorf terminals selected for their outstanding musicality. They are fixed on a bituminized aluminum plate. The cables are connected to the passive filter without soldering using pure copper lugs, also from Mundorf.