Home » Reviews » Earphones » Lime Ears Pneuma Review – Thunderstruck

Lime Ears Pneuma Review – Thunderstruck

Pros –

Gorgeous and highly isolating design, PWAudio cable included, Practical bass boost, Resolving yet dynamic bass, Revealing yet natural midrange, Clean and well-separated presentation, Source agnostic

Cons –

Bass lacks some coherence at times, Breathy vocal presentation won’t suit all, Bulkier uni shells, Average technical performance in-class

Verdict –

Lime Ears new flagship provides a thoroughly engaging, insightful yet versatile listen with gorgeous artisan design and custom PWAudio cable on top.

Introduction –

Lime Ears is a Polish CIEM manufacturer who really made a name for themselves with their original flagship, the Aether. This in-ear was lauded for its gorgeous tonality, and Lime Ears have been subtly tweaking this formula ever since. Emil, the man who started the operation, also takes a unique approach to acoustic design due to his background designing studio monitors. In turn, he creates in-ears with perhaps different goals to many competitors. The Pneuma is their latest creation and the first hybrid from the company. Many similarities are to be found, the same uni shell, the same bass switch permitting some adjustment of the sound based on the Fletcher-Munson law. Lime Ears are also targeting a slightly different style of sound, that being more lively than the Aether models. The Pneuma is the new flagship in pricing but is marketed as an alternative to the Aether in turn.

The Pneuma is available for 1800 EUR, you can read more about it and purchase one for yourself on Lime Ear’s website.

Disclaimer –

I would like to thank Pawel and Emil from Lime Ears very much for their quick communication and for providing me with the Pneuma for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.

Specifications –

  • Drivers: 1x DD Sub, 2x BA Mid-bass, 1x BA Mid, 1x BA Tweeter
  • Crossover: 4-way passive hybrid
  • Switchable Subwoofer Dynamic Driver

The Pitch –

Fletcher-Munson Law (FML)

Similar to past LE flagships, the Pneuma implements a bass-boost switch that increases the versatility of the sound. In particular, Lime Ears are addressing the FML, whereby, listeners perceive bass as being softer at lower volumes and louder at higher volumes relative to the rest of the sound. As such, low-volume listeners may prefer a slightly fuller sound with bass boost on while higher volume listeners may prefer the neutral setting. Of course, this also appeals to different sound preferences. With the introduction of a hybrid driver setup, the switch now controls the DD exclusively.

Passive hybrid crossover

The Pnuema designates driver duties in a different way than most IEMs. The DD exclusively handles sub-bass with 2x BA drivers also dedicated to the low-end, theoretically combining the agility of BA with the extension of a DD, even within the bass itself. We then observe 1x mid and 1x tweeter BA drivers. These drivers are united with a 4-way passive hybrid crossover.


Each bore features a varying diameter to enhance the frequency range covered by the connected drivers. In this instance, we observe a 1mm bore for the low-end and 2mm bores of the mids and highs. In theory, this enables a tighter low end and lower resonances of high-frequencies enabling greater extension and resolution.

BAM (Backfire Acoustically-damped Membrane)

A new technology introduced by the company to control back-pressure from the dynamic driver and reduce resonances. It is inspired by bass-reflex enclosures of studio monitors, giving Emil finer control over impulse response. In addition, open-cell memory foam has been implemented to reduce resonances and provide the most controlled bass possible. It appears as well that the Pneuma is a fully-sealed monitor, so this is a very interesting DD implementation.

PW Audio Cable

The Pnuema comes with Peter Wong’s famous No.10 cable out of the box. Though I would not argue that the Pneuma, like all flagships, is a value-orientated product, this cable does sweeten the deal with excellent build quality from one of the greats in custom cables. The wiring material is confidential, and it has been outfit with custom Lime Ears chin slider. It retails for $259 SGD.

Behind the Design –

The Pneuma is the first new flagship following the original Aether in over 3 years and also the first hybrid design from the company. Emil was kind enough to walk me through the design process and future plans for the company moving forwards. I thank the team at Lime Ears for accommodating my curiosity especially during this difficult and busy year, Emil’s thoughts follow:

Does the Pneuma replace the Aether R?

Since term “flagship” has several definitions (being the most expensive, most technically advanced and or most up-to-date construction), Pneuma checks all these boxes. So yes, from this standpoint it is higher model than Aether R. We have spend a lot of time and energy in this obviously difficult year to come up with something new both in terms driver selection, tuning technology, shell design and cable selection.
I’d say that Aether R is not the youngest construction on the market and I felt that it is time for him to give some space to some younger siblings. I try to make pretty contemporary sounding monitors and I’d be hesitant to call Aether R obsolete (what would we say about about tape recorders or tube compressors used on our favorite recordings, not to mention vintage guitars, amps and mics) but maybe we can say that it received some younger company in our portfolio.

What challenges are involved with designing a hybrid? Why hasn’t LE used a hybrid design before?

I was discouraged by several hybrid constructions I have listened to years ago where there seemed to be hardly any coherence between drivers of different types. It seemed like you have bunch of drivers and every of them is playing a different song. But it started to change gradually and I think that one of the turning points was listening to Elysium by Vision Ears. It sounded beautiful and coherent, even with such an extraordinary driver setup. It was clear evidence that dynamic driver could be implemented in way that really serves whole construction. I also noticed that industry came to the point where there is such variety of dynamic drivers that it would be possible to find some that suit my ideas.

The discouragement was gone and it helped to overcome my laziness. Balanced Armature drivers are much more similar in character to one another, and that makes them much more predictable. You can do a lot of designing through measurements since the changes you see on the measurements are close to the changes you will hear. Dynamic Drivers are another beast. You have different diameters, diaphragm geometries, diaphragm materials. There is much bigger variety in character between them and in way they blend with Balanced Armatures. So you have to do a lot of prototyping and listening. Like much more than in BA-only constructions (if you want to get it right).

It’s proper to listen to drivers alone, the same drivers in conjunction with one BA, two BAs and so on. It creates need for dozens of listening sessions. But thankfully, each listening session gives some experience (even when the driver tested will never make to any final construction). There is no doubt that this experiences will fuel incoming designs one way or another.

The bass driver setup is quite different on the Pneuma from existing designs (using 2xBA for mid-bass), why was this chosen?

Technically, the bass 2xBA driver handles range from about 100Hz to about 1000Hz. So it covers the bass and lower mids. And since Titanium-diaphragm DD (which is naturally on the warmer and slower side) was used for sub bass I felt it needed to be accompanied by highly-textured BA driver. Double drivers have smaller, faster-moving diaphragms and since there are two of them, their effective surface is pretty big. So by using double BA we can get pretty fast and textured bass and mids. Maintain the weight and body of the sound while being pretty accurate as in replicating body of many instruments and vocals.

Many companies mention that the most difficult part of designing an earphone is knowing when to stop! What are some things Lime Ears would like to work on in future?

Oh, this actually is the best part. You can’t really stop! I see earphone design as an evolution – an infinite process breeding different species being in relationship to each other, being part of bigger of ecosystem including driver manufacturers, cable manufacturers, DAC/DAP designers and naturally listeners.

Or it’s like some sort of saga. With another constructions being simply another chapters that evolve from previous ones and give beginning to next ones. The difficult art would be to make each design some sort of closed chapter. So the reader feels that they went through certain part of the story that is now complete.

But then another chapter is awaiting. And even when the novel is over, there is still plenty of room for another volumes.

That being said, we’re working on several projects and will be happy to share them in the future. 🙂

What are your thoughts on new driver types such as Estats?

I really, really like well implemented Estats. Their technical capabilities of expanding space and super-high end of the spectrum are wonderful. It’s great to observe all these new technologies emerging: Estat, planar magnetic, different types of DD, MEMS, you name it. Engineers are trying to push the boundaries of audio reproduction (which is not an easy thing and happens rather by evolution than revolution). But yeah big steps in this evolution are clearly noticeable and I would point Estats as one of them. I’m really happy to fiddle around with several new technologies and, when right time comes, I’d be happy to show the results it to the world of audio enthusiasts!

Next Page: Unboxing, Design & Fit



Picture of Ryan Soo

Ryan Soo

Avid writer, passionate photographer and sleep-deprived medical student, Ryan has an ongoing desire to bring quality products to the regular reader.


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