THIEL DESIGN PHILOSOPHY
All THIEL speakers are intended to be precision instruments that very accurately translate electronic information into musical sound. All
our efforts have been directed toward achieving extremely faithful translation of all tonal, spatial, transient and dynamic information
supplied by the amplifier. THIEL speakers are not intended to mask or mitigate shortcomings of the recording or other components in the
music playback system. We believe this approach is the only way to provide the potential of experiencing all the subtle aspects that help
make reproduced music a most enjoyable human experience.
Performance goals
Since quality of musical performance is a very complex issue it is helpful to objectively identify the aspects involved. We believe
musical performance can be described, with not much oversimplification, as performance in four areas.
Tonal fidelity includes overall octave-to-octave balance, the fidelity of timbres, absence of vowel-like colorations, and bass extension.
Spatial fidelity includes how wide and deep the performing space seems, how convincingly instruments are placed from the center to
beyond the speakers laterally, how realistic the depth perspective is, how little the speakers’ positions seem to be the source of the sound,
and how large the listening area is.
Transient fidelity includes how clearly and cleanly musically subtle low–level information is reproduced and how convincingly
realistic is the reproduction of the initial or “attack” portions of sounds.
Dynamic fidelity includes how well the speaker maintains the contrasts between loud and soft and how unstrained and effortless is the
reproduction of loud passages.
Fundamental design considerations
In our 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 line source designs which must place their different drivers side-by-side, causing the distance from each driver to the listener to
change with different listener positions.
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, allowing the possibility of a speaker system without significant fundamental limitations.
Technical requirements
The task of engineering a speaker system requires the translation of the musical performance goals into technical goals. Although there
are also many minor design considerations, the following are what we believe to be the major technical requirements that contribute to each
of the musical goals.
Tonal fidelity
• Accurate frequency response so as not to over or under emphasize any portion of the sound spectrum
• Absence of resonances in the drivers or cabinet so as not to introduce tonal colorations
Spatial fidelity
• Point-source, unipolar radiation
• Time response accuracy to preserve natural spatial cues
• Lack of cabinet diffraction
• Even dispersion of energy of all frequencies over a wide area
Transient fidelity
• Phase coherence to provide realistic reproduction of attack transients
• Very low energy storage to provide clarity of musical detail
Dynamic fidelity
• High output capability
• Low distortion
Design goals
The technical requirements result in the following major technical design goals:
1. Very uniform frequency response
2. Time response accuracy
3. Phase response accuracy
4. Low energy storage
5. Low distortion
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