6
OPER ATION MANUAL
REFERENZ HIGH TECH GEL-ABSORBER
FUNCTION
GENERAL
High-end and hi-fi systems are a combination of highly precise and delicate devices. Perfectly attuned to each
other, they allow music to be played back in outstanding quality. So that all components can work without
interference, just like sensitive measuring equipment they need to be kept free of vibrations and shocks as
far as possible. Vibrations are caused in different ways and they can be transmitted by structure-borne and
airborne noise.
STRUCTURE-BORNE SOUND
This means vibrations that are present on a structure, e.g. the housing of a device. A good example of this is
the loudspeaker box. The membranes of the speakers are set vibrating in a certain manner. As they are me-
chanically connected to the housing of the loudspeaker, they transfer vibrations to the housing. The scale of
these vibrations depends on the weight and the insulation of the housing. They are transferred to the area on
which they are standing, i.e. the floor. Two things now occur: On the one hand the floor gives off a part of the
structure-borne energy as airborne sound and this results in the typical droning noise; on the other hand the
structure-borne noise is often transferred to the hi-fi rack and therefore to the hi-fi devices. We will find out
more on the effects on the devices later.
AIRBORNE NOISE
This means vibrations that are transferred through the air and that usually can be heard by humans (with the
exceptions of infrasound and ultrasound). Airborne noise not only excites the eardrum but also acts on all
other surfaces it reaches. This also affects the hi-fi components and the surfaces on which they are standing,
particularly if they are not very solid. As the primary purpose of a hi-fi system is to create sound, shaking of the
devices due to the sound they are producing is a natural by-product.
SUMMARY
The combination of airborne and structure-borne noise not only causes the glasses in the cupboard and exhi-
bits in display cases to vibrate mechanically but also the components of the hi-fi system itself. Experiments
have shown that the sound of the components is affected by the effects of vibrations. One reason for this is
the capacity values of components in relation to each other that change continuously due to the vibrations.
HELP!
The Reference Hightech Gel Absorbers from in-akustik form a solid sound basis that is available as a combina-
tion set for all weight classes. The Reference Hightech Gel Absorbers from in-akustik have a special gel at their
core that can take up or absorb vibration energy. They decouple loudspeakers and devices from the surface on
which they are standing. You could say that it is sufficient to decouple the loudspeakers. But, as described abo-
ve, there is still airborne noise that also acts on the surface on which the devices are standing. So it therefore
makes sense to decouple all of the devices from the surfaces on which they are standing. The same applies to
devices such as CD players or hard drives that produce mechanical vibrations themselves that need to be kept
away from other components as far as this is possible.
QUALITY NOT QUANTITY
While we are on the subject: The weight of the devices influences the effectiveness of the absorbers or the ab-
sorbent material. In particular the damping ratio alters depending on the frequency and the self-resonance. Th-
erefore it makes sense to adjust the absorber to the weight of the respective component. in-akustik performed
various measurements in order to find the perfect mix for the absorber gels for the different weight classes. This
involved placing gel mixtures on an agitation plate and then different masses (weights) were placed onto it.
The agitation plate was caused to vibrate with a noise signal (pink noise). An acceleration sensor measured the
vibrations of the agitation plate and the vibrations in comparison with the vibrations present at the mass. The
suspicion was that softer gel mixtures should be used for lighter devices and harder ones for heavy devices. The
