Klipsch Heresy IV Floorstanding Loudspeaker Review

Posted on 16th December, 2021

Klipsch Heresy IV Floorstanding Loudspeaker Review

Rafael Todes auditions the latest version of this iconic American floorstander…


Heresy IV Floorstander


Klipsch Heresy IV Review

Klipsch was founded in Hope, Arkansas, USA, in 1947 by Paul Klipsch. He lived to the ripe old age of 98, and the Heresy range has been in production since 1964. It’s so-called because, in the beginning, the company’s speakers were corner placed and triangular; when Paul came up with this more conventional-looking oblong box, his employees called it a heresy. The name has stuck and remains a feature of the range. Klipsch Heritage Series products are built to order, with cabinets that are still handmade in the factory with a lead time of typically six to eight weeks.

The latest Heresy IV version of this classic speaker remains a three-way design, rear-ported in this recent revision and mounted on a pedestal that throws the speaker up at an angle or around ten degrees. Klipsch uses its celebrated Tractix horn throats as a bass port, for both the tweeter and midrange drivers. The shape is close to that of an equilateral triangle but with some curvature. A well-designed throat will typically increase the dispersion angle, giving a large area of listening ‘sweetspot’ in a room, as well as reducing internal resonance.

The IV’s tweeter has a titanium diaphragm and a newly developed phase plug with better high-frequency dispersion. The midrange driver is the polyimide diaphragm K-702 compression design; the driver compresses air in a small cavity before passing through the horn. It is inherently more efficient than a conventional driver and offers better dynamics and fidelity. The woofer is a pleated coated cloth suspension affair; the Klipsch K-28-E12 bass driver measures 305mm, quite a substantial thing for a unit of this size.

Klipsch Heresy IV Review

Round the back, the aluminium input panel can accommodate large, high-quality speaker cables. Strong and solid binding posts provide the capability for bi-wiring or bi-amping. Internally, the Heresy IV utilises Audioquest Type 4 wiring with Star-Quad Geometry, carbon-loaded insulation, nitrogen-injected PE and solid long-grain copper conductors. This is said to ensure the purest signal transfer from input to crossover network to drivers.

The speaker comes in a range of finishes, comprising Black Ash, Natural Cherry, Distressed Oak, and American Walnut. Together with the retro-looking front grills, this makes for an iconic nineteen fifties Americana look – as classic as, say, a McIntosh amplifier. There’s no doubt that this loudspeaker has a real physical presence in any listening room, and that’s before you play any music!

For this review, my main reference system comprised VAC Phi 200s tube power amplifiers, a Townshend Allegri Reference preamplifier, a PS10 power regenerator, and a dCS Bartok streaming DAC. As soon as you start playing music, it’s very clear to hear that the Heresy IV is exceptionally efficient – which is, of course, what Klipsch is famous for. The manufacturer claims 99dB sensitivity, and I have no reason to question this. Although I normally use high powered 200W tube amplifiers, this loudspeaker could be driven with a fraction of this wattage – making it ideal for tube fans.

Klipsch Heresy IV Review


This is a big speaker, in pretty much every way. It has a large, capacious sound that’s up and at you with no messing around. It captures the vibrancy of music as well as its physical heft. You get a lot of sound over a wide expanse of your listening room, and the Heresy IV brilliantly articulates the scale and power of the music. It has a great ability to pick out percussion with life-like realism, too. Indeed, musically the performance is thoroughly engaging. I love its fast and dynamic nature that almost ‘throws’ the sound out at you.

When I first unboxed my review pair of Heresy IVs, I initially found them to be quite shouty at the top end. Live FM radio broadcasts of classic concerts sounded good, as did vintage vinyl, but digital sources sounded excessively bright. With the passing of a few hours break-in, this changed, and digital sources became far more palatable – very good in fact, and certainly not bright. Indeed by the end of the review period, I was most pleased by how smooth they sounded.

Klipsch Heresy IV Review

I was most impressed by the width of the soundstage upon hearing Messiaen’s epic Turangalila Symphony, with the Finish Radio Symphony Orchestra conducted by Hannu Lintu. The Klipsch threw out a generous recorded acoustic with a great sense of presence. Bass was solid and well-formed, and the overall sound was tight and taut. This said, I was left wanting a bit more detail within that wide soundstage. This speaker captured many aspects of the recording well, but I wouldn’t quite describe the sonic picture as holographic – in the way you’d get from an electrostatic design, for example. Instead, it gave me a fine general gist of what was happening on stage; there was some lack of image precision compared to more conventional floorstanders, and its tonality wasn’t as neutral as many. For example, I heard a slight lack of body to the piano in the midrange.

Klipsch Heresy IV Review

Although left-to-right soundstaging is excellent, the Heresy IV doesn’t do stage depth as well as some similarly priced speaker rivals. Sir Simon Rattle conducting Haydn’s eccentric Sinfonia Concertante played by the Berlin Philharmonic, showed me that the wide spread of the recorded acoustic didn’t extend forwards and backwards quite so well. Here the sound proved surprisingly warm and pleasant, but it didn’t quite differentiate between players at the rear of the hall, and at the front, as well as some. This tended to be far less apparent on pop and rock music, where stage depth is less of an issue; here I rather enjoyed the Klipsch’s very intimate, ‘next to the stage’ approach.

I also found that changing my power amplifiers lessened the effect. I substituted another valve amplifier in my collection – a restored Marantz 8B running EL34s, and dating from 1962. This was one of the finest amplifiers of this period and would have been a regular partner for Klipsch loudspeakers back in the day. What a combination! Those sweet little EL34 power valves brought more air to the proceedings than the KT88s of the VAC, and I heard an energy and life to the recording that jumped right out at me. I’ve never heard the Marantz sound so good; it was as if it had found its life partner. The rhythmic tension was excellent, as it delivered fast and accurate transients with toe-tapping drive.

Klipsch Heresy IV Review

Listening to Colin Davis conducting Stravinsky’s Dumbarton Oaks, the synergy was obvious. Referring back to the Haydn piece, I was impressed by the more fluid sound than the VACs could muster. There had been a slightly mechanical quality to the strings, but they were now far more fluid. As someone who teaches the violin, it reminded me of when I had a pupil who was seemingly of modest ability. Yet one day, I saw him perform in a concert and was blown away by his ability to communicate. That’s not what he did in lessons, it’s what he did in concerts! Similarly, the venerable Marantz 8B has an uncanny ability to draw from the Klipsch something that a more skilled, sophisticated and muscular amplifier cannot.

Properly matched, the Heresy IV really began cooking on gas. You Look Good to Me by the Oscar Peterson Trio sounded great, the double bass pizzicati stinging and ringing authentically, and the rhythm section staying tight and utterly believable. The whole track rocked along and swung, really giving the sense of three great players having spontaneous musical fun together. The boogie factor was back!

Klipsch Heresy IV Review


Klipsch’s latest Heresy IV is an iconic loudspeaker, one that has been developed and finessed over many decades. Think of it as the Jack Daniels of the speaker world due to its quality, classic styling and constant presence over such a long time. Many people love the Klipsch sound, and I can see why. It’s not as delicate and nuanced as some modern designs, but its strengths are many and highly apparent. That big-hearted visceral sound – with its puppy-dog enthusiasm for musical timing – is hard not to like.

It’s also why Klipsch loudspeakers can be found in the second largest chain of cinemas in the USA. The ability to conjure up such a big sweet spot where there is a large audience sitting in a wide variety of places really counts for something. Picky audiophiles might not warm to it, but I think that when properly matched to the right amp, the Heresy IV makes a great case for itself. Also, the way it makes low power amplifiers thrive is something that needs to be heard to be believed – and a huge and oft-overlooked bonus. Properly partnered, this is one hell of a speaker!

For more information visit Klipsch

    Rafael Todes's avatar

    Rafael Todes

    Gifted violinist Rafael is one quarter of the Allegri String Quartet, playing second fiddle. Once a member of the CBSO under Sir Simon Rattle, he now teaches at London’s Junior Royal Academy. A long-time audiophile, he’s still on a quest for the perfect sound.

    Posted in:Hi-Fi Loudspeakers Floor Standing Applause Awards 2022
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