Sound worlds are experienced quite physically, which was not uncommon with the large D'Appolito speakers of the 80s, when the bass settled in the pit of the stomach. As original children of the 80s, we often marveled at this with our mouths open. Financially, such a thing was unattainable, but dreaming was allowed.
With the amount of loudspeakers that exist today, such a performance is rather a rare spectacle, because the dinosaurs of loudspeakers were already threatened with extinction, but only almost. Back to the roots is all the rage, and so speakers like the Agile Dynamik have reclaimed a firm place among the slim models.
The speaker tech kit includes all electronics, speakers, parts and accessories, except for the wood for the cabinet.
Curious now? Click here for the detailed build report.
Content
1.) A symphony from the past that has arrived in the present with Arcosia.
2.) Crossover optimization considering the beryllium tweeter.
3.) The eye listens: Kit perfection for your Agile dynamics.
4.) Goal achieved: Finally, High End with classic virtues again.

A symphony from the past that has arrived in the present with Arcosia.
We present you a new highlight in the development of our Eton loudspeakers: the new Agile dynamics completely for DIY with everything you need from one source.
What parameters are required for the development of such a high-quality loudspeaker?
An idea that originated in Christian's first Agile. So it was decided not only to marry the Agile with a top class beryllium tweeter, but to optimize the whole concept. For such a development, the budget had to be increased, that was clear. So the way was clear for a team that could give free rein to its expertise in development, room acoustics and cabinet construction. The team solution of working with Christian on the Agile turns out to be the right one in retrospect, which benefits the performance of this speaker.
The Agile dynamics are way ahead with its innovative Arcosia drivers among the top speaker drivers on the market. Paired with a Beryllium tweeter of the extra class, which has already earned an excellent reputation in various speaker constructions, the basic conditions for a harmonious marriage among top drivers are given.

An excerpt from the Eton product description. Arcosia chassis.
The dynamic diaphragm geometry in magnesium composite design fascinates with an authentic reproduction. The flow-optimized drive and the open phase plug design also support a spatially vivid sound image. The Arcosia drivers are equipped with unique and exceptional features. The magnesium composite cone is perforated with holes of increasing diameter, spiraling from the phase plus. The cone is then coated from the rear, with the coating material protruding through the holes and creating small, round bumps on the front of the cone. This process was developed to dampen unwanted resonances in lightweight magnesium cones. This unique method smooths the frequency response without the use of a stiffer surround, which can have the undesirable effect of clouding the sound. The vented phase plug also cools the voice coil and eliminates distortion that can occur behind a conventional dust cab. The rear poleplate of the Arcosia has multiple holes to ensure better voice coil venting. Again, a spiral pattern is milled from the vents outward into the back plate. This particular pole plate is polished and actually too bad to hide inside the case.

Technique: crossover optimization considering the beryllium tweeter
In the revision of the Agile, not only the tweeter was replaced, but also the crossover was subtly optimized. In the bass range, the 4-inch Arcosia drivers were relieved and the crossover frequency was increased by a good 50 Hz, so that they can play even cleaner and the intermodulation distortions are reduced, so that the mid and high frequencies can be reproduced even cleaner. Here, it is particularly important that the levels that the Arcosia drivers still play below 100 Hz were further lowered by the slope that was shifted upwards in the frequency range. The 8-inch basses, on the other hand, were raised slightly in the upper bass, allowing them to play fully in their optimal working range - i.e. bass and upper bass, and to stimulate the listening room optimally due to their geometric arrangement.
The main optimization in the high frequency concerns the acoustic and electrical adjustment of the phase. In the acoustic adjustment of the phase, the temporal behavior of the drivers - which is always influenced by a passive crossover - is optimized so that both the radiation pattern and the transient response of the loudspeaker are very uniform, as with a full-range driver. This means that through the choice of electrical filters and their design it is basically possible to compensate for the depth offset of the different sound origins. This can be seen very well in the waterfall diagram, because here there is no transition between midrange and tweeter (the temporally arranged lines run horizontally through). It is often seen that the tweeters decay earlier and the filter edge of the midrange is well visible in the waterfall diagram as a temporally later event.
Optimizing the electrical phase is about reducing the reactance of the crossover and thus harmonizing the impedance so that amplifiers have optimal conditions to drive the fine, sensitive frequency range as well. With speakers of the acoustic quality of an Agile, it is absolutely essential to optimize all factors and this includes not only the careful choice of crossover components but also the electrical consideration of the complex load (impedance) for the amplifier.
Built-up crossovers: A service for our high quality kits
Images below:
With high-end turnouts of the extra class like Agile or Satorique, it can become extensive piles of components. If the turnouts also have to be built by the customer, errors can quickly occur. These are difficult to analyze in retrospect, even for the trained ear.
The coils manufactured in Intertechnik's own winding shop enable values that are not available in the standard range in this way. The same applies to our AUDYN capacitors, which have also stood for an excellent price-performance ratio for years.
Measurements: Frequency response and impedance

Distortion 90db and angle

Waterfall
The eye listens: Kit perfection for your Agile dynamics

The case already from 599 Euro
...for perfect cuts in MDF wood or according to your wishes.
A construction drawing, the building instructions and an email service for the construction project we provide free with the purchase of a kit.
If you don't want to build everything yourself, you can enjoy the CNC milled case parts.

Lamellos for fixing the components help to ensure that everything remains in its correct place when clamping and fixing the individual housing parts.

SaRaiFo veneers
- Save the RainForest
We support this and have chosen such a veneer for our Agile Dynamics project.
You can get inspired at: www.designholz.com Category SaRaiFo-Fineline-Veneers.
Another option would be to have a ready-made case built for you. As always, this is all a question of price.


The multifunctional cutout of the tweeter still leaves possibilities open for alternatives. With its 35mm thickness, the baffle represents a real heavyweight among the baffles. Personally, I like the combination of matt white lacquered baffle and veneered Makassar
very well.
The whole thing is complemented by a screwable crossover compartment, through which one can still very nicely see the continuous inner matrix of the cabinet. The contrast of the Arcosia chassis with the white baffle completes the picture.



Goal achieved: High end with classic virtues again at last
Sound worlds are experienced quite physically, which was not uncommon with the large D'Appolito speakers of the 80s, when the bass settled in the pit of the stomach. As original children of the 80s, we often marveled at this with our mouths open. Financially, such a thing was unattainable, but dreaming was allowed.
With the amount of loudspeakers that exist today, such an appearance is rather a rare spectacle, because the dinosaurs of the speaker boxes were already threatened with extinction, but only almost . Back to the roots is fully in vogue and so speakers like the Agile Dynamik have reclaimed a firm place among the slim models.
Why then are so few examples to be heard in the high-quality self-build?
It's because the effort is extremely high to build a sound sculpture that meets today's demands in design and sound. If one were to offer the Agile Dynamics as a finished loudspeaker, a purchase sum would come together, which today can correspond to that of a small car. That we find ourselves here in the classical stereo area is probably clear and also presupposes a high-quality amplifier.
Also high-quality analog crossovers are here a must and not the choice. That also with us the Frostis, as I affectionately call the small DSP Amps, move in, is probably due to the trend of the time, but please not here.
The crossover philosophy has already become a tradition with us. As much as it must be, but also not less. For this reason there is only one crossover for a construct and not three different ones.
Such a loudspeaker should master all disciplines such as tonality, spatial representation as well as coarse and fine dynamics. And so we can look forward to the sound reports of our customers, because everyone has a different perception in their four walls.
What could be repeated by all would be the open mouths of the guests when they hear and marvel that you have built something like this yourselves: a leftover relic from long forgotten times with the sound that modern loudspeaker technology can deliver today.
A sound experience with unmistakable bass that has never lost its character since the 80s until today.