Q. Why does THIEL use cone drivers and cabinet enclosures
rather than panels, ribbons, or membranes?
A. When THIEL Audio was founded, designer Jim
Thiel experimented with several design types in order to decide
what type of speaker he wanted to make. He came to the conclusion
that while dynamic (cone) speakers were far from perfect, the
problems they had were not inherent, but potentially had solutions,
whereas membrane speakers had fundamental limitations that could
not be gotten around, especially in output capability versus
size versus bass extension.
Also, membrane loudspeakers, because of their large radiating
area, have poor dispersion of energy throughout the listening
area, especially at high frequencies. The dipolar radiation of
membrane speakers puts unnatural out-of-phase energy into the
room which makes room placement critical, makes bass and imaging
performance quite variable, makes placement near walls more problematic,
and obscures some imaging information.
In THIEL's opinion, natural spatial reproduction requires
creating a realistic sound field within the listening room by
mimicking the properties of natural sound sources. These properties
include wide area radiation and the absence of out-of-phase energy.
To meet these requirements, all THIEL speakers employ dynamic
drivers. Dynamic drivers have the advantages of providing a point
source radiation pattern with good dispersion of sound over a
wide area, great dynamic capability, good bass capability, and
a lack of rearward out-of-phase energy. Another advantage of
dynamic drivers is that their small size allows the multiple
drivers to be arranged in one vertical line. This alignment avoids
the problem of side-by-side driver placement which causes the
distances from each driver to the listener to change with different
The major potential disadvantages of dynamic speakers are
diaphragm resonances ("cone breakup"), cabinet resonances
and cabinet diffraction. Also, they share with other types of
speakers the potential problems of time and phase errors introduced
by multiple drivers and their crossovers. None of these problems
is a fundamental limit and all can be minimized or eliminated
by thorough and innovative engineering.