Making the immeasurable measurable
Simulations also play a key role in the adjacent room. Before a prototype part is even produced, Guy Layfield knows more about its properties than can realistically be measured. On several screens, programs and sub-calculations are running, which we are asked not to mention. How does the driver behave under condition X, and how does the driver concept work? “For example, here we can see what happens inside the drivers at any point, even though this isn’t measurable. We nevertheless know it, and we know it very, very accurately — and can carry out development work much more precisely even before the prototypes.” All scripts and many software enhancements are in-house developments by the team. The simpler brute force simulations usually run overnight on very powerful workstations. More complex calculations take days, sometimes even a week. Which components do they simulate most frequently? The many moving parts and materials of the drivers — and the magnet system, of course.
Leif Böhme fetches a prototype of the KH 80 DSP housing from the cabinet one desk away. “The housing is another component that contributes significantly to overall performance,” says the developer. How exactly do the side walls have to be designed, strutted, and manufactured so that they do not resonate? Böhme points to the cover of the prototype: “In this version, it still had too much movement at 500 Hertz. We then tested and eliminated this movement in a FEM (Finite Element Method) simulation.” BEM (Boundary Element Method) calculations run on his second screen to simulate sound radiation. But development goes far beyond resistance to resonance. The waveguide, which contributes to the extraordinary directivity, was also created here. This significantly determines the neutrality outside the beam axis, thus providing for the interaction of the loudspeaker with the space. This is a very important factor that makes Neumann monitors sound so neutral even under the widest range of installation and room conditions. The elliptical shape ensures a wide listening range.