An analogy: the lively box

Is the idea of a mass density model that is direction and frequency dependent reasonable? Consider a rigid box, and inside it a weight suspended between springs and constrained so that it, the weight, can move only in the direction of the springs. To a person shaking this box in any direction orthogonal to the spring alignment it is just a simple massy object, not dependent on frequency. Shaking it in the spring direction is quite a different matter - the weight will be quite dependent on the frequency of shaking. Is this a good analogy? It has one thing in common with our model: at 0Hz it becomes isotropic. We want our dynamic model to have the same static properties as our previous model.