Ilumnia

Illumnia Vocalis 

The dynamic loudspeaker has existed for well over 100 years. In principle, all these dynamic loudspeakers are constructed roughly the same way. There is a membrane that needs to be set in motion, the Conus, for bass or midrange units, or the dome in the case of a tweeter. A voice coil is attached to these membranes, a small tube with wire wound around it, a coil. This coil hangs very precisely in the magnetic field, which is generated by a strong magnet. The magnet has a magnetic pole, and precisely in between is a magnetic gap, about a millimeter wide, and in this magnetic gap fits exactly the voice coil, with the copper coil. That is precision work, because the coil must move back and forth through the magnetic gap when a music signal passes through it, but it must not touch the magnet or magnetic pole of course. That causes unwanted noise, and the voice coil will also break, and then the unit no longer works.

For this reason, the entire moving part is suspended from the speaker frame. The voice coil sits in a sturdy membrane, which can move back and forth: The Spider.

The conus itself, on the other hand, the outside so to speak, is also attached to the speaker frame, with also, often rubber, membrane, which is also flexible: The Surround.  

So far, so good, you might think, and the technique for this has been known for 100 years. It works. But here's the thing. Actually, the Spider is a pain. A necessity, but one with serious drawbacks. The Spider restricts the movements of the moving conus/coil, so the conus cannot move linearly back and forth. But what's even worse is that the Spider itself also makes noise. You can hear it, and that's of course not good. The only sound waves should come from the Conus or Dome itself, and not from the Spider. But the surround at the end of the conus is also not ideal. The Conus must be very light, preferably no more than a few grams, to move it back and forth thousands of times per second, in time with the music. But now there is a surround on the side of the Conus, which holds it in place. But that surround also has mass, and a certain stiffness, and it actually holds the conus back. So on one side the Conus is driven, and there is a Spider that makes noise and holds back the voice coil, and on the other side of the Conus is a surround that also restricts the movements of the Conus, and exerts unwanted forces on this Conus. The result is that the Conus does not do exactly what it should, and could do.

Yet this technique has been applied for decades on about 99% of all dynamic loudspeakers in the world, to this day. A Spider is cheap and functional and a surround too. And if well executed, it can sound very good indeed. 

Yet Tom and Jef Nuyts from the always friendly Belgium thought differently about it. They wanted to design a speaker unit without a surround, and without a spider.

After many years and a thousand different designs, they succeeded. The woofer/midrange driver of the Ilumnia Vocalis or the Magister has no Spider, and no Surround, and is therefore 99% linear over its entire range, and moreover this unit can easily reproduce 15,000 Hz. And that is very special.

Good units alone won't do it. There also needs to be a proper enclosure, and a high-quality crossover. The enclosure is made with thick sheets of CNC-milled plywood, stacked on top of each other until the enclosure is formed. This is an excellent acoustic solution and also very heavy and solid. The crossover is simple, because it is a 2-way loudspeaker, and is built with quality components. Moreover, 8KHz is very high as a crossover frequency, so small coils can be used.