Diptyque Audio 140 Mark II Isodynamic Loudspeaker Review

Diptyque Audio is a name few Americans know—Diptyque plans to change this. In 2022, they partnered with Fidelity Imports to expand their dealer base in the USA. The 140 Mark IIs sit in the middle of a five-product range from the company and utilize the latest in design prowess from the engineering team. At $17,000 per pair, they are in the arena of a high-end loudspeaker, yet are still attainable in a world in which $250,000 loudspeakers are available.

Diptyque Audio developed its first prototype loudspeaker in 2001. It was orchestrated by Gilles Douziech and Eric Poix, both of whom have extensive training at places like Douziech’s tenure at the acoustic laboratory of Toulouse University, Hewlett Packard, Siemens, Philips, and General Electric (Gilles Douziech studied at Toulouse for 10 years alone). Poix brought with him his expertise in mechanics and ironwork. Both had (and still have) a love of music and wanted to bring to the world their vision of the ideal music makers. There is no better path to success than combining talented people with endless passion.

Their relentless pursuit of quality is evident when experiencing these speakers in person. They may look a bit frail in pictures, but when one realizes that over 65 percent of their 85-pound weight is high-strength steel, and when carrying each speaker, getting the feel that they are ‘not bendable,’ the strength of their design becomes evident. All work is either done in-house or by companies local to Diptyque’s headquarters, where quality control is paramount.

The 140 Mark IIs are not called ‘Mark IIs’ for marketing purposes. During the Covid shutdowns, Mr. Douziech and Poix decided to continue to work on an ultimate speaker. This speaker is now known as the $50,000 Reference. The Reference introduced significant improvements to the Push-Pull/Isodynamic designs at Diptyque. Two years after COVID-19, these improvements were incorporated into the 140/160 loudspeakers, thus the Mark II designation.

It is the 1950s, and high-end audio is in its infancy. Klipsch, JBL, and Electrovoice are known for their highly efficient horn-loaded loudspeakers. They were massive designs that required great care in room selection and setup. Acoustic Research popularized a much smaller electro-dynamic speaker based on a sealed ‘acoustic suspension’ design. Their speakers required more power than did their horn-loaded counterparts but at a fraction of the size. With the advent of both stereo systems and higher-powered amplifiers, they quickly became huge sellers. It would not be an exaggeration to suggest that Acoustic Research is one of the primary drivers that made the in-home stereo a popular item.

There was, apart from the electro-dynamic design, another concept in speakers: direct diffusion. The first widely available direct diffusion loudspeaker was the Quad ESL-57, which remained in production for almost a quarter century until the ESL-63 replaced it in the early 1980s.

Direct diffusion loudspeakers require large panels for wide bandwidth reproduction of music and have been firmly entrenched in high-end audio since the introduction of the Quad ESL-57 over 60 years ago. The Quad design is more specifically an electrostatic speaker which has also been used quite successfully by Martin Logan. Both company’s designs require an electrical field to operate, and refinements over the decades have brought both to exceptionally high standards in audio reproduction.

Other directions taken in direct diffusion designs are from Apogee with their wideband aluminum ribbon and most famously, Magnepan with their Isodynamic line of speakers. It is with this Isodynamic loudspeaker from Magnepan that Diptyque has the most in common. Both companies are quite well versed with each other, and they share a friendship and common ground, with each acknowledging the other company has a tremendous product.

The Diptyque ideal was its development of the PPBM (push-pull bipolar magnet) which the company claims is a major evolution of Magneplanar technology. The complete lack of a box resonator (which most speakers have) is one of several design choices that lead to the performance as delivered.

The bass modules each are similar to those in the Reference speakers. Each consists of a large surface membrane which is flat, rectangular, and lightweight in Mylar. Each panel is covered with a quality conductor and then placed in front of a magnetic circuit of the same dimensions. This gives the 140 Mark II’s a large emission surface and high speed over the entire bandwidth, without the coloration of a box enclosure. As the Isodynamic design is known for its increased directivity as frequencies increase, Diptyque solved this issue by placing magnets on both sides of the membrane, which strengthens the bass and accelerates the transient response. In their testing of this development, it was discovered that this not only made for what we perceive as a ‘faster’ speaker, but it was also more linear across the bandwidth, which will lead to not only better bass extension and definition but less distortion at any level of SPL up to the speaker’s limits. Each tweeter (located on the right side of the right speaker and left side of the left speaker) is a similar design, with a 55 cm long Mylar tape anchored between dual magnets. Each tweeter is mounted on its own plate, and the plate is precisely fitted into birch plywood, allowing for a decoupling of the tweeter.

The strength of the enclosure itself combines with the open, dipolar design to give the listener an audio experience that completely avoids the resonances that are inherent in all box-style speaker enclosures.

A pair of Diptyque 140 Mark IIs comes in a remarkably simple package. Both speakers are packed in dense foam and placed in a cardboard box. The cardboard box then is placed in a wooden crate to keep everything safe for shipping. The speaker assembly is about a five-minute job for two people. The stabilizing foot comes with two bolts and an Allen wrench. Secure the foot to the speakers and screw in the included spiked foot on the other side of the speaker and you are ready to go.

The speakers were placed in the normal location for all the high-end speakers we test here, with about 10 degrees of toe in. Each speaker is about 12 feet from the listening position and nine feet apart.

We have a wide variety of pre-amps, power amps, and integrated amps from which to choose. For this test, the well-known NAD M33 integrated was selected for its simple elegance and excellent reputation. The source for all listening was a Yamaha CD-2100S SACD/CD player. Several months ago, we upgraded our cabling and power distribution to Clarus products. For the NAD Integrated and the Yamaha disc player, a Clarus Concerto power distribution component anchored the source of electricity. This added the additional benefit of knowing the NAD was receiving the full 120 volts it needs to perform at its best. For power cords, the Clarus Aqua II cords were used. XLR from the Yamaha to the NAD were Clarus Aqua II and the speaker cables were also Clarus Aqua II.

This entire system as driven is about $35,000 for Diptyque speakers, NAD amplifier, Yamaha source and all upgraded Clarus cables and power conditioning. As I type this, I am looking at a pair of speaker cables for $55,000. This simple system does bring up a point for audiophiles who are seeking high value. An integrated amp can give a lot of bang for your hard-earned dollar. Not only are there countless examples of powerful integrateds with state-of-the-art sound, but the cost savings extends beyond having a single chassis versus two with a separate pre-amp/power amp style system. When upgrading cables, it’s one less power cord, one less interconnect, and possibly even one less power distribution center.

We have everything set up and are now going to run sine waves through the speakers while I get caught up at work. I will be back in a few days, but it will feel like mere seconds to you. Ok – I am back. Let’s do some listening!

Associated Equipment:

Power Conditioner: Clarus Concerto, Clarus Duet
Power Cord: Clarus Aqua II
Interconnects: Clarus Aqua II XLR Balanced
Speaker Cables: Clarus Aqua II
Source: Yamaha CD-S2100, Bluesound Node X (Qobuz), OPPO 105D
Pre-Amplifiers: Marantz AV10, Michi P5, Cambridge Audio Edge NQ
Power Amplifiers: Michi S5, McIntosh MC303, Marantz AMP10, Cambridge Audio Edge W
Integrated Amplifiers: NAD M33, Rogers High Fidelity KWM-88, Cambridge Audio EVO150
Speakers: Legacy Audio Focus XD, Diptyque 140 Mark II, Sonus faber Maxima Amator, Vaughan Line Array Major, Ohm Walsh SSC-4900, DALI Oberon 9, Heretic AD612, Harbeth SHL5 Plus XD, Definitive Technology Dymenson 5.0 system, Starke Sound IC-H2
Subwoofers: MJ Acoustics Kensington (2), Sonus faber Gravis VI (2), Axiom Audio EP600 (2), Starke Sound Sub 35

Track 2 is ‘Rubberbandman,’ which opens with fast percussion leading into a frenetic singing section steeped in baritone. There is an abundance of what can only be described as ‘let us test these speakers’ noises. Examples include a swoosh of wind across the sound stage and a chorus well behind the lead singer. The overall feel is of a deep and wide soundstage with the ability to almost disappear.

Track 3 is Dede Priest treating us to ‘Blues Wine.’ The opening kick drum comes through in a manner that cannot be a planar speaker. It is tight, tuneful, and welcomes Dede’s lovely voice with ease. The see-through quality of these Diptyque speakers is again some of the best this reviewer has experienced. The sound of a drumstick on the rim, the laid-back guitar work, and her vocals are nothing short of completely engaging.

Let’s explore Track 6 before wrapping up this disc. The presentation is Marcus Miller’s ‘Power,’ which is performed live. A toe-tapping bass track leads to lots of percussion, more guitar, and lots of brass. It’s a massive sound and requires a lot of effort for any speaker to handle all these instruments with credibility. Once again, the 140s were more than up to the task. It was in this song that another notable trait emerged. These speakers are so clear and so distortion-free, that adding to the equation their lightning-fast reflexes, one might think it isn’t loud. My wife stopped in the listening room and started to talk. It was at that moment that it became clear these speakers have a lot of capacity for SPL. I could not hear her voice at all.

Some final words on Extended Dynamic Experience 4 with the Diptyque 140 Mark IIs; these towers delivered on every track. The bass was tight and potent to below 30 Hz. The soundstage is immense. One can be outside the left or right speaker and still get an excellent sound stage. The only caveat on this is the listener cannot have their ears more than 50 inches off the floor if one wants the full experience. Physically, that is about the top of the high-end transducer which excels in horizontal dispersion, with vertical dispersion intended to be primarily within the bottom and top of the high- frequency driver.

The guitar soars well above one’s listening position, and when the sax chimes in, it is with such speed and fidelity that it becomes apparent that this is a special loudspeaker.

‘Learning to Fly’ is a departure for Pink Floyd. It has an almost Reggae style to the bass track at the beginning of the song. Honest. It’s a Pink Floyd song to which you could actually dance. The sound quality remains impressive and brings that intense ‘you are there’ feel to the performance.

‘Another Brick in the Wall, Part II’ is the real star of the show, in terms of showing off the 140s. Opening with the British-style phone ring at a distance, the famous helicopter then does its flyover, leading into the guitar work with which any Pink Floyd fan is familiar.

This presentation continues to build until the full chorus and band present a crescendo, and the Diptyques push one back with an almost limitless soundstage of width and depth. Once one hears a huge sound like this, going back to a monitor speaker won’t be easy. Each female chorus member is easily discerned, and the entire song is awe-inspiring through these towers.

‘Time’ begins with those alarms going off, and again we have it presented as this larger-than-life (or at least my listening room) feeling of intense power. This transitions to the percussion and guitars, and one can clearly ‘see’ where each is on stage. Of particular note is the incredibly adept manner in which these Planar speakers deliver the ultra-fast drum work on skin. Each leading edge is instantly heard, then released, only to present the next in perfect pitch and timing.

Every track on ‘Pulse’ is outstanding, but brevity prevents one from writing about each one. With that in mind, let’s wrap this up with a gut-wrenching version of ‘Run Like Hell.’ The guitar effects spanning across the stage are goose-bump worthy and when the bass guitar and percussion kicks in, we are treated to yet another danceable Pink Floyd song. It is hard rock combined with high fidelity that needs to be heard on these speakers.

The Diptyque 140 Mark II speakers have handled two discs that excel in macro-dynamics. How will they fare with material that requires delicacy and finesse first, and crescendos second?

On soaring numbers like ‘Sonata for 4 Hands’, we are hit with some powerful keystrokes and frenetic playing that will test any speaker’s ability to deliver credible crescendos. It’s the type of performance that makes one lean back a bit, as it is so powerful and in one’s personal space.

‘Dolly Suite Op. 56: IV Kitty Vaise’ lets the 140s stretch their legs with a combination of very delicate notes that hang on with wonderful air to more demanding strikes that test the output abilities of the French towers.

The well-reproduced piano is as difficult a task as can be handed to any audio system, and the Diptyque’s rendition of each piece was natural and capable of delivering the softest single stroke to mass attacks in which one can feel the passion (and perhaps anger) of the pianist.

Pure piano as is demonstrated on this disc is not my normal listening material. The 140 Mark IIs are so natural and capable of bringing the performances home that I was quite able to just enjoy each piece without interruption. My daughter is an accomplished performer who loves playing piano and singing opera (she also has been in over 40 theatrical productions), so I often get to hear the natural sound of a properly played piano.

The 140s were again impressive with their ability to make a piano sound like a piano. While this may seem like a simple task, it isn’t. Most pianists loathe hearing piano reproduced on an audio system. For fun, I had her sit in for about 30 minutes of this performance. Her assessment as someone who does not like large speakers is these ‘Audio Truffles’ (her phrase – I am not that adept) might just change her mind about having an edge-of-the-art audio system in her house someday.

The performance was so engaging that I ended up listening to over two hours of various tracks with amazing results. The Flute was rendered so beautifully that relaxing and listening became of utmost importance. The orchestra’s crescendos would come in large waves, with the 140s bringing me into the concert house with authority.

Valeria Kafelnikov’s harp would then ease its way into the performance with startling realism, and the harp and flute would work with each other with a style and sophisticated ease that made the two hours go by all too quickly. There was no care about ‘which track is this.’ I was strictly enjoying music in the listening space without a care in the world.

This was the polar opposite of the approach taken by ‘Extended Dynamic Experience 4,’ which requires intense concentration to ascertain how accurately a speaker reproduces each track.

These two ladies, and the orchestra accompanying them, made the world stop for a while. It was music and nothing more. It was also the revelation that the Diptyque 140 Mark IIs are nothing short of machines that can deliver music in all forms into a listening room with accuracy that seems impossible yet without a hint of harshness. They can go toe to toe with any audiophile speaker on the planet, all while making one forget that one is listening to an audiophile speaker pair. This is the ultimate goal for any loudspeaker, to present the music and then get out of the way.

It was almost a sad moment when the performance stopped until I remembered that the concert was available again at the press of a button.

Planar speakers are often characterized by wildly fluctuating response curves and limited output, especially those using the various magna-planar technologies. The Diptyque 140 Mark IIs continued to deliver surprising results in the measurements they delivered in our listening room.

Starting with the response curve, let’s look at the curve where a linear response curve is at its most important: 100-10,000 Hz. The French Planars managed to be within a window of +/- 3.5 dB from 100 to 10,000 Hz. This is an extraordinary response curve for a monopole speaker, and I don’t know of another Planar speaker that can claim such a linear response curve in a listening space. This curve matches up quite well with our listening sessions. Every instrument and vocal was as if one had a window to the live event, and the measurement of this response curve backs this up nicely.

From 150 Hz and down (the overlap from 100 to 150 Hz was intentional), we see an equally adept response curve with the added bass response from our listening room’s gain in that 30-40 Hz range. The useful response was surprisingly robust, hitting just below 30 Hz with more authority than one would expect out of a relatively modest-sized magnetostatic loudspeaker. Objectively speaking, the Diptyque 140 Mark IIs deliver bass at a level that will satisfy most music lovers without the need for a subwoofer. Subjectively, should you wish to add a subwoofer, I recommend looking for a proper sealed design and seeking the dealer’s help in set up for one’s room. Without careful placement and tuning, a subwoofer might be detrimental to the performance.

Finally, let us look at the THD numbers. This curve was taken at 75 dB at a distance of 4 meters from the speakers, which translates into about 95 dB at one foot. As with the response curve, the 140s managed to keep distortion levels quite low:

30 Hz measured @ 3.37 %, 40 Hz @ 1.87%, 50 Hz @ 0.98 %, 60 Hz @ 1.19%

70 Hz @ 0.83% and 80 Hz – 10,000 Hz: Under 0.8 %

This again shows excellent performance from the Diptyque towers. If one were to do some research on other highly regarded Planar speakers, one would find that the response curve and THD levels were more widely varied on the response curve and with much higher THD levels. The 140 Mark IIs are competitive with many highly regarded, high-end dynamic speakers, in terms of distortion-free output at most listening levels and a wide, flat frequency response.

While expensive at $17,000 a pair, the Diptyque Audio 140 Mark II Isodynamic Loudspeakers deliver the clarity and precision of far more expensive models.

In November 2022, our Editor-In-Chief, Carlo Lo Raso, invited me to attend the Capital Audio Fest in Rockville, Maryland. This was nearing the end of my second year with Secrets of Home Theater and High Fidelity, along with 45 years as an audiophile and 20 years as a freelance writer on various audio forum sites. This would be the first show of its type that I attended as a writer.

It was at that show that I experienced Diptyque speakers for the first time. Steve Jain, the USA importer, had a pair of the DP107s set up in the typical hotel suite turned listening room. Steve mentioned to Carlo that they had bass. Carlo asked to hear ‘Cousin Dupree’ from Steely Dan. There was bass in abundance! It was not quite as deep and powerful as a pair of high-end subwoofers would deliver, but it was deep and SO tuneful, with no overhang. The clarity was excellent, and the depth and width of the sound stage were astonishing.

At the 2023 Capital Audio Fest, Jain and Company brought the latest model, the 140 Mark II. After discussion and adult beverages, I was able to wrestle the show samples for this review. After the show, we loaded them into my 2023 Jeep Grand Cherokee 4XE Hybrid, and it was off to my listening room with the French towers.

Over the last six weeks, these speakers have done nothing but make me love music even more. They have turned me into a classical music aficionado, yet my normal affection for rock and jazz has not abated one iota. The Diptyque 140 Mark IIs are an outstanding loudspeaker with few limits from 30 to 20,000 Hz and at levels that, while not rock concert level powerful, are everything I could ask for in terms of spending hours listening.

Their sound stage, accuracy, and ability to transport the listener into the performance place them in that arena of an exceptional high-end transducer. The only possible issue I found in this review for potential purchasers is they won’t play as loud as some other speakers in their price range. This was never an issue in our listening room, but if your taste in music and preferred sound pressure levels approach rock concert levels, these might not be your thing. If you value perfect pitch, the ability to bring instruments and vocals to life, and you want to experience a window into the performance, you will want to audition a pair of these speakers immediately.

The Diptyque 140 Mark IIs were designed to be an affordable loudspeaker that can deliver edge-of-the- art sound. The company has succeeded at every level one could ask for, especially for the asking price. While $17,000 is not inexpensive, the investment in a pair of these Fabulous French music makers might just last a lifetime. This reviewer has decided to make this investment, and the Diptyque 140 Mark II towers are now part of our reference system.