The first version of Heresy acoustics by the American company Klipsch was released in 1957. In 1985, the second version, Heresy II, appeared, and 21 years later - "number three", released in 2006 in honor of the company's sixtieth anniversary.
Unlike the Heresy II with their polymer diffusers in the tweeter and midrange (a phenolic dome on the midrange and a rigid polyester membrane on the HF), the new version of the speakers is equipped with titanium diaphragms in both cases. Other crossover tuning frequencies gave a slightly narrowed band for the midrange (the previous version had 700 and 6000 Hz, respectively). Heresy III also has the possibility of bi-wiring connection. Both speakers are loaded with speakers: the medium frequency – with exponential, and the tweeter – with Tractrix. The horn made according to the tractris is shorter than the exponential one, because, repeating the behavior of the latter in the throat and in the first half of the length of the horn, it "bends" closer to the exit and fully opens faster than the exponential one. Generally speaking, this idea was first put forward by the engineer Paul Voight in 1926, and one of its specific implementations was patented by Paul Klipsch twenty years later and has been present in his company's acoustics ever since. As always, Klipsch uses compression speakers with a closed chamber installed on the back, which allows equalizing the load on the outer and inner surfaces.
The sensitivity of the new Heresy has become higher, albeit slightly, and the magnetic system on the midrange is said to be more powerful. Unlike the old Klipsch, with an Electro-Voice woofer, the latest version of the Heresy is equipped with 12-inch woofers of a different company, although it is still clearly of professional origin. For them, the manufacturer also indicates a large overload capacity. A light and rigid diffuser of a concentric structure made of paper pulp with the addition of directional fibers with a corrugated suspension (looks like a fabric with impregnation).
The cases are made of 18-mm MDF sheets. Beveled stands ensure the orientation of the emitters upwards, at the level of the listener's ear.

Specifications

Frequency response, Hz – 58-20,000 (+/- 3 dB)
Number of bands - 3 (LF - 30.5 cm, paper-fiber composite, microwave - 4.45 cm, compression, with a titanium diaphragm and with an exponential horn, HF - 2.5 cm compression, with a titanium diaphragm and with a Tractrix horn) ;
cut-off frequencies of 850 Hz and 5000 Hz
Acoustic design is a closed box
Resistance, Ohm - 8
Sensitivity, dB – 99
Dimensions of one column, cm - 60.5 x 39.4 x 33.7
Weight of one column, kg – 20.