When I try to listen to a low-power amplifier, I am so confused about what speakers to match. Although the bookshelf speakers will also show good sound quality, the sensitivity of most small bookshelf speakers is not so qualified. So these small power amplifiers are not allowed to show their potential, until I met the Klipsch Heresy IV horn speaker.

The Klipsch And Its Horn

Speaking of the horn, you will find that it is impossible not to talk about Klipsch in the United States. This brand, founded by Mr. Paul W. Klipsch in Elkhart, Indiana, the USA in 1946, has become synonymous with the horn. For more than 60 years, Klipsch has maintained a unique position in the field of horn speakers.


Mr. Klipsch is a pioneer in the study of horn technology. In the laboratory, he found that the unit diaphragm plus the horn can increase the efficiency of sound generation by 10-50 times! It means that to achieve the same audio output power, the use of horn technology can significantly reduce the amplitude of the diaphragm. So it can obtain lower distortion, more linear performance, and increase the dynamic range and control the level of diffusion.

Mr. Klipsch called the horn product he developed as Klipschorn. Because the efficiency of the horn is very high, even if you use a 7-8 watt amplifier, you can find the effect of the burst. For a long time, Klipsch has focused on horn technology, from professional theatres to high-fidelity speakers, from high-end home theatres to multimedia computer speakers. The success of home theatre systems, which has laid the dominant position of the company in the North American market.

The Evolution of The Klipsch Heresy Serise

The history of Klipsch Heresy IV speakers can be traced back to 1957, but the latest version ($ 2999) has been completely redesigned for the fourth iteration.

Klipsch heresy IV

The Klipsch Heresy IV Horn Speaker is the entry product in the Heritage Classic series. Heresy’s three-way speaker was first introduced in 1957 when the company designed it as a center speaker. The size of this center channel speaker is designed to be short so that it can be placed under the screen without blocking. And the effect focuses more on the accuracy of the midrange. At the same time, it is also required to obtain an excellent dynamic and low-frequency extension to better match the high-performance Klipschorn.

It wasn’t until 1964 that Klipsch officially named Heresy as the center-sounding speaker with an advanced concept. It is said that during the research and development process, Mr. Klipsch’s friends thought that he could not design this center channel speaker specially used with Klipschorn. However, it turned out to be a success, and even more, it was later found to be as outstanding as a stereo speaker and can be sold in a pair.

Heresy is the evergreen model of the factory. It was not until 1985 that the factory improved the speakers and the Heresy Ⅱ was born. It was only in 2020 that the fourth-generation Heresy, which had been renovated in all aspects, was launched.

Klipsch heresy IV

Klipsch Heresy IV, the Best So Far

The brand-new Klipsch Heresy IV is the latest improved product. The appearance still maintains the style of the old model. In terms of the size, the Heresy IV, which is only 63 cm high, can be classified as a large bookshelf speaker. However, Klipsch’s original design was used as a floor-mounted center speaker, so it was designed with a base that tilts the speaker back so that when the speaker is placed on the ground, it can also put the sound axis to the standard listening height.

Heresy IV uses a titanium diaphragm high-frequency driver, a K-704 Tractrix horn, which is installed above the new mid-range compression driver, and a premium high-fidelity network. Bass is provided by a 12-inch woofer. There is a brand new crossover and internal cable provided by Audioquest. The new design also has the rear port appear on Heresy for the first time, Klipsch claims that this can better extend the bass.

Klipsch Heresy

The hand-made cabinet is furnished with matching wooden veneers. They are taller and narrower than the previous generation, and the grille has also been updated. The base is removable to increase flexibility.

Heresy IV is the entry-level speaker of Klipsch’s flagship Heritage series. Still, it delivers super audio experiences and is available in American walnut, natural cherry, satin black soot and distressed oak.

Klipsch Heresy IV Finish options

Directivity And Efficiency

The horn speaker itself has relatively strong directivity. This so-called short-distance focus point is only relatively speaking. In the actual audition, it is found that the best listening distance of Heresy IV can not be too close, about 3-4 meters is most suitable, which also meets the conditions of use of most families. The benefit of strong directivity is that the sound energy is concentrated within a specific range, thereby reducing the sound reflection of the space environment.

Most of today’s speaker design concepts are pursuing small-diameter and narrow cabinets. The reason is that small-diameter speakers can get faster response speed, and small cabinets can get better sound field reproduction effects. From this point of view, the design of Heresy IV seems outdated. Still, an irreplaceable advantage of this horn speaker has made it eye-catching. That is, the sensitivity has increased from 96dB to 99dB comparing with the previous generation!

What does this mean? It means low-power amplifier players can also feel the power of that explosion. The 3dB increase means that the output power of the audio amplifier can be reduced by half. Relatively speaking, power is more abundant, and the distortion rate can be significantly reduced.

Klipsch Heresy IV Specifications

  • 3-way design
  • tweeter:K-107-TI 1” (2.54cm) Titanium diaphragm compression driver
  • midrange: K-702 1.75” (4.45cm) polyimide diaphragm compression driver
  • woofer: K-28-E 12” (30.48cm) Fiber-composite cone woofer
  • bass-reflex enclosure with rear-firing Tractrix port
  • frequency response: 48-20,000 Hz (±4dB)
  • sensitivity: 99 dB
  • nominal impedance: 8 ohms compatible
  • power handling: 100 watts continuous (400 watts peak)
  • weight: 45 lbs. (each)
  • maximum SPL:116dB Continuous
  • crossover frequency: HF 4500HZ, MF 850HZ
  • inputs: Dual binding posts/bi-wire/bi-amp
  • height:24.81” (63.01cm)
  • width:15.5” (39.37cm)
  • depth:13.25” (33.66cm)
  • weight:45lbs (20.41kg)