Review: Klipsch Heresy III


Mis à jour le 26 February 2019.

Test Klipsch Heresy III

This week we tested the Klipsch Heresy III ?compact? loudspeaker. This legendary three-way model created 60 years ago is equipped with 3 drivers and 2 acoustic horns and is designed to offer an ultra-realistic sound no matter which amplifier you team it up with.

Klipsch Heresy III: a little bit of history

Klipsch was created in 1957 as a result of Paul W. Klipsch?s desire to create a loudspeaker that could be easily transported by plane. Klipsch also wanted to promote stereophonic sound, as he truly believed in the potential of this emerging technology. The Klipschhorn loudspeaker was available from a large majority of hi-fi retailers at the time, but since monophony was the standard back then, each store had only a single model on display. Paul Klipsch then decided to use the Heresy to demonstrate the stereo format for loudspeakers (a Klipschorn with a Heresy). The Klipsch Heresy loudspeaker is a heretic more than in name: usually, designing and building a compact loudspeaker means not using horn enclosures for each driver. The bass driver is therefore usually placed in a sealed enclosure. For Paul W. Klipsch, this screamed heresy.

Test Klipsch Heresy III
The Klipsch Heresy III can be taken off its tilted stand to be transferred to a more conventional speaker stand or placed on a piece of furniture.

Klipsch Heresy III: technical specifications

The Klipsch Heresy III loudspeaker is a 3-way model fitted with a removable, tilting stand. Alternatively, you can place the loudspeaker on a different stand or simply set it directly on the floor. This model features three drivers, two of which are horn-loaded. The 12″ bass driver?s membrane is composed of cellulose pulp, with a small pleat surround and a remarkably lightweight set of mobile parts (it is therefore not designed for long cone excursion). Fitted within a sealed enclosure, the bass driver offers a frequency response ranging from 58 Hz (-3 dB) to around 800 Hz. Beyond 800 Hz, the 1.75″ horn-loaded titanium dome, equipped with a compression chamber, kicks in. From 5 kHz to 20 kHz, it?s the 2.5 titanium dome tweeter (which also encases a compression chamber and is mounted on a square Tractrix horn) that takes over the reins. The Klipsch Heresy III loudspeaker has a sensitivity of 99 dB for 1 watt of power supplied (measured at a distance of 1 m). That?s 2 dB more than the Heresy II and a feat made possible by an improved bass driver.

Test Klipsch Heresy III
The Klipsch Heresy III?s stand is equipped with four steel feet and is shipped pre-assembled.

Klipsch Heresy III: the advantages of acoustic horns

Klipsch has been using acoustic horns for its loudspeakers for decades, to the point that it even became its trademark. In the middle of the 20th century, a large majority of manufacturers had no other choice but to turn to horns in order to optimize their loudspeakers? sensitivity. The transistor had not yet been invented, and amplifiers were working with power tubes and their average power rarely surpassed’ 5 Watts. With the advent of the acoustic horn, each driver?s sensitivity was increased by a few precious decibels. Still today, Klipsch continues to equip its entire range of speakers with acoustic horns. While the brand no longer uses acoustic horns for its bass drivers, as this implies using folded horns (which take up an enormous amount of space ? see the Klipschorn, for example), Klipsch?s compression chamber tweeters are still horn-loaded. What?s the point? Well, by mechanically amplifying the sound produced by the tweeter ? whose sensitivity is naturally rather high because of its rear compression chamber ? the horn significantly reduces the amplifier?s power requirements. The loudspeaker?s electronic crossover filter thus drastically cuts down on the amount of electric current sent to the tweeter, bringing with it the advantage of a thermal compression considerably inferior to that of a traditional tweeter. As a result, distortion is brought to a minimum and the resulting sound is much clearer.

Test Klipsch Heresy III
The front of the loudspeaker is covered with granular resin (similar to plaster), which serves to eliminate sound reflections. The central horn is particularly deep.

Klipsch Heresy III: sealed enclosures and bass handling

The Heresy III?s bass driver comes in a considerable, 12″ format often reserved for subwoofers and thus rarely seen on hi-fi loudspeakers. But the Klipsch K-28E is not a P.A. driver, and its lightweight set of mobile parts makes it particularly comfortable in the higher bass and low-medium ranges. Placed within a sealed enclosure, the bass driver offers an excellent transient response, much superior to that of a bass-reflex enclosure. The only downside: Klipsch measured it at 58 Kz, which is a seemingly absurd number given the size of the driver. Moreover, this number pales in comparison to those indicated by the competition, whose much smaller drivers make for more compact loudspeakers. However, the Klipsch team knows what artisanally-crafted hi-fi is all about and is thus well aware that clean lows down to 58 Hz are better than diving down 10 or 20 Hz lower and obtaining a muddy delivery.

Moreover, Klipsch seems to have been compelled to set bass frequency response at 58 Hz for a host of other reasons. Notably, 58 Hz is the frequency at which a bass driver?s sensitivity loses 3 dB. Below this frequency, damping becomes more pronounced and steeper ? a combination capable of making bass frequencies imperceptible. Meanwhile, using a bass-reflex enclosure entails an extra-steep curve of 24 dB per octave ? which is twice as steep as that of a sealed enclosure.

In other words, the bass driver on Klipsch?s Heresy III continues to be ?efficient? well below 58 Hz. In addition, its natural resonance is set very low, at approximately 30 Hz.

Test Klipsch Heresy III
The Klipsch Heresy III?s acoustic cloth grill is furnished with magnets
Test Klipsch Heresy III
The grill, once slotted into place, sits flush with the front of the speaker

Klipsch Heresy III: cabinetmaking and finish quality

The Klipsch Heresy III loudspeaker is handmade in the USA, as are all the loudspeakers in the brand’s Heritage range. Each plywood board in the cabinet?s frame is approximately three quarters of an thick, and the front and back of the loudspeaker are covered with a black, granular resin that has damping properties. The top, sides, and bottom of the speaker, as well as its stand, are elegantly veneered with natural wood. The model we tested had a warm, walnut finish. The front of the speaker is fitted with a wide grill composed of highly-resistant acoustic cloth. In addition to being magnetic, the grill is decorated with the Klipsch logo bearing the initials of Paul W. Klipsch. A label glued onto the rear of the speaker informs the buyer of the unit?s serial number and bears the signature of its quality checker. A double screw terminal connection allows for bi-amplification. The LF terminal is destined to power the bass driver, while the HF terminal serves to power the two horn-loaded dome tweeters.

The Klipsch Heresy loudspeaker has a width of nearly 40 cm, a height of 61 cm (stand included), and a depth of 34 cm. Weighing in at 20 kg, it is a well-built speaker.

Test Klipsch Heresy III
The Heresy III?s Klipsch logo, bearing the initials of Paul W. Klipsch

Klipsch Heresy III: target audience

The Klipshc H3 cannot be labeled and delivers a truly unique sound. It was designed to offer an extremely realistic sound, close to a real live experience. Classical music, jazz, opera, electro, funk, rock, no genre if off-limit for this speaker. Initially designed for hi-fi, it is also very efficient – even excellent – in a home cinema installation. After all, speakers used in cinemas behind acoustically transparent screens are very similar to the Klipsch Heressy III, although capable of handling a much higher power level since they were built to play much louder. The precision and sensitivity of the Klipsch Heresy III make it a perfect speaker for film and series soundtracks. Since it is sold as a standalone speaker or as a pair, it is possible to use three models as front speakers. Given its technical characteristics, the Klipsch Heresy III can work with very low power amplifiers (2×10 W for example).

The Heresy III is particularly recommended for those who are looking for a clear and very dynamic sound, which can be massive and enticing while balanced and flattering to the ear.

Test Klipsch Heresy III

Klipsch Heresy III: test conditions

We spent a lot of time testing the Klipsch Heresy III with different amplifiers (Hegel H80, Pioneer SC-LX59, Denon DRA-100 and NuPrime IDA-8?) and loudspeaker cables Viard Audio Premium HP, Viard Audio Silver HD12, Audioquest Star Quad Type 4, Audioquest Rocket 88). As with the Klipsch RF-7 MKII, the Klipsch Heresy III allows the listener to fully hear all the differences between electronics, a convenient feature to fine-tune an installation.

Klipsch Heresy III: listening impressions

We couldn’t resist becoming immediately enamored with the Klipsch Heresy III?s sound. The soundstage is incredibly vast and solid; even the songs you love and have listened to time and again will provide a new delight for the ears as they reveal nuances you have never heard before. An ultra-quick loudspeaker which serenely conveys even the slightest shifts in rhythm, the Klipsch Heresy III is capable of bringing to light ? with great discernment ? details which are normally left in the dark by conventional loudspeakers. While the Heresy III?s use of horns might lead some to assume that the sound would be unnaturally projected, this is not the case. In fact, the listening experience stands in direct opposition to that stereotypical sound we might have feared would be produced by a model initially created some 60 years ago. The musicality of the Heresy III is unquestionable. Send it some jazz, and its sound will prove surprisingly warm, enhanced by the slightest shift in dynamics and by passages as rich as they are subtle. Even the most exuberant brass sections are generously and gracefully conveyed. Send it some rock, and the Heresy lets you enjoy those wailing electric guitar riffs like rarely before, making you feel like you?re in the front row of a live concert while benefitting from the comfort of your own home. Paired with a NuPrime IDA-8, the Klipsch Heresy III turns Muse?s concert at Saitama into a genuine fireworks display (which is exactly what it?s meant to be), continually surprising the listener while bringing the sound to a higher level of clarity than ever before. As the volume is turned up, the Klipsch H3 neither forces nor narrows the vastness of the soundstage. The result is simple: the more complex the sound, the more there is for the listener to enjoy.

Test Klipsch Heresy III

It would be pointless to expect to hear sound restituted in the same way as with several small drivers nestled into a bass reflex enclosure. The Heresy III won’t give you an all-out roar, but what it will give you is a nuanced bass which is also vigorous and tight. The large emissive surface of the 12″ driver (equivalent to two 8″ drivers) often makes for an impressive sound restitution. For example, using the Heresy III as a home cinema loudspeaker results in an exceptionally realistic dynamic range, even with a mid-range amplifier like the Denon DRA-100. Even though the loudspeaker is hardly functional below 50 Hz, it doesn’t need to be: its punch and mastery of bass frequency behavior guarantees that nothing gets left out.


Low-medium: these frequencies are restituted by the 12″ driver, and its lightning-fast reaction time is highly flattering to human voices and bass guitars, whose lines are easy to follow. Nothing drags and the sound is clear and intelligible.
Medium: Once the 1.75″ titanium dome takes over the reins, its presence is unmistakable and its articulation absolutely flawless. The listening experience remains clear even with the volume turned down.
High-medium: the 1.75″ dome and the tweeter combine their forces to render frequency ranges between 3000 and 5000 Hz.

Exquisitely fluid and energetic, no doubt thanks to the titanium dome which can be found on several of Klipsch?s 2-way loudspeaker models and on the Heresy III. The cutoff frequency of the dome tweeter is much higher that regularly seen on other models. The treble register brings more depth to the listening experience, without tainting or coloring it. The tweeter knows how to make itself discreet and only steps in at the most opportune moments.

Klipsch Heresy III 70th Anniversary Edition

Klipsch Heresy III: conclusions

What we liked

  • The reassuring sound
  • The wide soundstage
  • The right-on-the-money bass delivery
  • The overall sound articulation
  • The simplicity of the design
  • The visually-appealing acoustic grill
  • The wood finish

What we would have liked
Frankly, nothing comes to mind. But we know that others have regretted the fact that this loudspeaker doesn’t seek to achieve a realistic bass delivery below 50 Hz. Then again, you can’t have it all! Klipsch?s catalog also features the Klipsch Heritage Cornwall III, which has a 15″ driver and is significantly more imposing. For those who seek the ultimate home cinema experience, an effective solution would be to pair the Heresy III with a high-quality sealed-enclosure subwoofer fitted with a 10″ or 12″ driver. Alternatively, a subwoofer with a bass-reflex enclosure would do the trick on the condition that its driver is at least 12″. Since a pair of Klipsch Heresy III loudspeakers is capable of churning out 122 dB at a distance of 1 meter, we would even advise using a pair of subwoofers. To this end, why not choose Klipsch subwoofers?

In short, we found a lot to love in the Klipsch Heresy III and consider it to be a simply exceptional model ? and a real work of art. Graceful and delicate when the music calls for it to be so, and an unrestrained, brute force when given the occasion. The Heresy III dances around the acoustical traps set by many living rooms while knowing instinctively how to maintain an unfailingly pleasant sound balance, regardless of which amplifier you connect it to. Pay extra attention to the loudspeaker cables, and avoid silver-plated cables in order to eliminate the risk of overpowering the horn-loaded dome drivers. A truly one-of-a-kind listening experience.

One last word to remind readers that Klipsch is celebrating its 70th anniversary with a special edition ? made available for purchase in France only a few days ago ? released as the Klipsch Heresy III 70th Anniversary Edition. Drivers and filters are rigorously identical to the original: only the veneer has changed, along with the acoustic grill and the logo. Klipsch has manufactured a mere seventy pairs and only one of these is available in France. Where? You?ve guessed it ? this rare and outstanding model can only be found here at Son-Vidé

Test Klipsch Heresy III


  1. Thanks for the detailed review. I am tempted to grab a set of Heresy for my Elekit TU8200 running 6CA7 on ultra linear mode. There is no shop to try them and have to buy only online. The issue is I cannot return the speakers if I didn’t like. I am a bit worried of the ‘horn effect’ some write about klipsch speakers. I was using my decade old Jamo E855 towers. They were good but sold them off to make space for new ones. unable to make a decision if to risk my money. Don’t want to go again for a tower with 5″ to 6″ mid woofers and sub 89dB.

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