Extract from the test bench published in "PRESTIGE AUDIO VIDEO" n ° 26:

Audio-Dynamique is one of the oldest speaker kit specialists in France. His expertise in the development of systems is immense, based on a solid experience of speakers of all types, loads and filters. Thus, the amateur who wants to embark on the realization of an acoustic speaker, has the maximum security as to the final result of listening. Audio-Dynamique is equipped with an acoustic laboratory with measurement equipment that can guarantee the performance of the systems it offers. Its range of acoustic speakers to achieve oneself ranges from small inexpensive models to huge systems such as the model Aéria, a true jewel.
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This two-way, high-efficiency system is based on a specially designed 38cm bass-reflex driver plus JBL 2426 J mid-high compression chamber loaded by an exponentially exponential wooden circular horn. listening or measurements. This set is not new. It was introduced more than six years ago at the last kit show and has benefited from numerous filter and load developments to achieve the current mature system by offering a fascinating listening style, and we weigh our words, in terms of dynamic capacity, analytical power, control of spatial dispersion, but above all, providing an obvious listening pleasure.
This exceptional result is due to the perseverance of development but especially to a solid common sense to solve the problems raised by the high efficiency systems. Indeed, these are very difficult to master if you do not want to fall into the caricature sound. The beauty of transcription reached by the Aéria is out of proportion with most of the sets that can be proposed "all mounted". The kit system Aéria is composed of a serious cabinet 85 cm high for a depth of 57 cm and a width of 46 cm. These proportions are ideal, giving pride of place to the depth of the speaker, limiting the risk of overpressure and return waves through the large speaker of 38 cm.
The cabinet is made of a 22 mm laminated chipboard sandwich with 12 mm density medium plus 25 mm stiffening brackets. The very large 20 cm diameter vent with a depth of 18 cm can open either at the front or at the back of the speaker. This very large diameter vent was not calculated by chance. It takes into account the great depth of the charging cabinet as well as the maximum radiation in
below 35 Hz. The bass speaker of 38 cm and has a better balance of pressure on both sides of its membrane, promoting the transient response while giving a feeling of faster on the transients even in I extreme-serious. With a vent of smaller diameter. the difference is noticeable in terms of amplitude and freedom, by a compressed side and transients appearing compacted. The possible disadvantage with a big vent could be to hear everything that goes on inside the speaker (deplorable cavernous effect) if the internal damping was not optimized in order to have the maximum of details while by limiting the colorations. The rigidity of the walls is essential so that they do not radiate with a delay time. Here, the sandwich technique provides an ideal response with the support of internal tassels that support the opposite faces.
The 38 cm woofer is a specific model under the reference Audio-dynamic AD380 PM100. This superb transducer is made from a molded light alloy bowl with a 180 mm ferrite and machined field plates with a very high precision. The membrane is very close to that of JBL Pro models with its wide corrugations. The suspension of the half-foam roller type ensures deflections of the order of 2 cm without the 10 cm diameter voice coil (!) Leaving the optimum field.
We know the main 38 cm made by JBL, Altec, Electrovoice, Celestion, Audax, but this one particularly impressed us with its bite on the attacks and its lack of barking effect around 300 Hz. 'Audio-Dynamique has looked for and found a very light mobile unit, 77 g (to compare with the more than 100 g of JBL LE15A for example) thus getting closer to the performances of an Altec 416, while being able to descend lower since in free field the resonance frequency is between 28 and 32 Hz.2426j.jpg
The symmetrical topology filter for the bass cell uses two inductors for each of the branches and two parallel capacities between them necessary for the attenuation slope of 12 dB / octave on the bass side around the hinge frequency of 500 Hz and on the side 6 dB / octave dium (made possible by the large emitting surface of the horn which allows the compression chamber 2426 J to go down as low without causing distortion of non-linearity of the air pressure between the inverted dome of the membrane and the phasing part). In the mid-high-frequency filter cell, which is also symmetrical and very well thought out, you can feel the experience of Audio-Dynamique in the use of compressions that are not easy to practice correctly if you do not want to fall into a sound of "carousel sound". This very simple filtering avoids many phase rotation problems while ensuring a very good recovery regardless of the overall sound level between the two transducers.
The JBL compression chamber 2426 is a 16 ohm J model. This 1 inch (2.5 cm) output motor features a ferrite-based magnetic circuit that provides a 18,000 G field in the very narrow air gap of the magnetic circuit that plays the 5.2 voice coil. cm diameter on aluminum support fixed to the titanium diaphragm. The entire mobile equipment is mounted on a bakelite crown with centering pins and fixing screws for easy change. The choice of model J over model H was fixed following measurements revealing that the 16 ohm model rose higher in the treble, practically up to 16 kHz without attenuation while the 8 ohm model began to fall from of 14 kHz. The titanium diaphragm has a thickness of only 0.05 mm, the dome being one piece with the diamond-like peripheral suspension, geometry adopted to avoid the effects of tilting. The concave portion of the dome looks at a phasing piece whose concentric channel geometry has been calculated to open at the same length in all points from the dome to the mouth.
This engine is mounted at the rear of a single (circular) horn of 50 cm in diameter, turned in solid wood of a certain variety of mahogany. It is actually made of six blocks of wood assembled with each other requiring a very long work for a perfect surface condition. A specific piece for mounting the motor with recessed screws facilitates centering to avoid any effect of rebondfd350.jpg.
The circular flag by the waveform that it propagates poses much less problems of recovery with a serious speaker of rather large diameter than those of type multi-cellular or radial. This superb solid wood pavilion rema-lisation avoids all these problems of inco-controlled resonances, it is perfectly inert, it means instantly and to the measurements, the curve of answer does not present any small irregularity revealing of suspicious stains. Likewise on the 3D curve you will notice the fantastic and progressive damping of the curves without any resonance peaks. This is the first time that we see that a pavilion does not sound absolutely even pushing the level up to almost 120 dB! The emitting surface has been calculated for the best possible compromise between the low cutoff frequency without attenuating the treble. The results speak for themselves, the addition of a tweeter is useless. Now, we must know that a two-way system perfectly coherent in phase is very clearly superior to a multipathies with random intersections.
A superb achievement that deserves that we dwell on its construction. In any case, the HP House team is here to help high-performance enthusiasts solve any problems they may have during assembly.
Listening conditions and subjective analysis:
We have never heard anything so neutral, so precise in the analysis and also consistent from low to mid-high to high A concert piano sounds like a concert piano, without being truncated in its power acoustic, without having its notes abruptly planed notes, without the concert hall becomes a room deaf. From the accompaniment of the left hand to the melodic play of the right hand, the balance of levels between chord and notes is perfect. One never has the impression of a piano cut in two, totally lacking cohesion of stamp, the restitution is beautiful "to cry" it is seized by the truth of the interpretation, the absence of lid on the hyper level peaks, this total freedom on all registers.pm380mo.jpg
On male or female voices, the Aéria set behaves with exemplary neutrality. Naturally flowing, the phrasing of the performers is surprisingly intelligible. Even at very high levels, the voices are concise, punctuated in space with mouths that do not stretch in cinemascope and do not transform into Donald Duke in the relay zone with the woofer. The serious is breathtaking by its speed Those who are familiar with the 416 Altec recognize a beautiful transparency between 200 and 800 Hz, but by cons they do not have the weight or the impression of mass in the extreme serious of a 2215 JBL for example. But the Audio-Dynamique team found with their transducer the ideal compromise between a descent in the infra-grave impressive (it can nail you to the wall) with the desired transparency in the 300-600 Hz zone. pasty or cardboardy cone bottom. The hyper-rigid load does not radiate and the large vent provides real support below 40 Hz, with incredible physical sound pressure.
But the most surprising lies in the stereo image of these large systems. It is certainly the coherence of diffusion of this immense two-way system which surprised us most. Compared to the sectoral pavilions, even controlled directivity, one can sit, stand, move to the right or left of the speaker, without noting a change in level in the upper midrange acute, or mood swings between the speed of the two transducers. The circular pavilion perfectly mastered plays here fully its role of real sound fusion.
Really this high-performance system has left us with an unforgettable memory. It is curious to see that this is an auditorium devoted exclusively to kits, which gives a lesson to many manufacturers of so-called high-end speakers with very high efficiency, which for some have not come to the end of harmful colorations or lack of coherence. With time, patience, and an adequate acoustic and electronic environment, you will gain access from these systems to another world of sound that has nothing to do with the narrowness and introversion of numbers of finished speakers so-called "high end".
Congratulations to the Audio-Dynamique team for the realization of their own bass transducer, the study and the realization of their medium-high horn, but especially the development of a coherent whole which does not suffer from criticism. neither measures, nor listening.
By Patrick Vercher and Jacques Vallienne.