⌈ LIME EARS is a Polish company founded in 2012 by EMIL STOŁECKI and KAROLINA ROMAN in Wrocław. It specializes in designing and building "personal monitor systems", ie headphones used by musicians on stage. We are testing the company's top model, PNEUMA. ⌋

IME EARS IS A SPECIALIST COMPANY focused on one type of product: in-ear headphones designed for professional use, as the so-called "personal stage monitors". It offers headphones from the top shelf in terms of quality and price. Lime Ears is also one of those Polish companies that are equally known locally and globally. On stage, her characteristic, "customized" headphones can be seen in the ears of members of such bands as Katatonia, Decapitated, Happysad, Bokka, Lao Che, and also Dawid Podsiadło.

Headphones of this type are called IEM, short for In-Ear Monitor. They actually are in-ear headphones, used by musicians as personal monitors during performances. Such monitors makes the stage is much quieter, which in turn allows producers to precisely set the volume, as well as the proportions of individual musicians, adjusted only to them. Other companies offering IEM headphones both for the stage and for the home use worth mentioning are: JH Audio, Sensaphonics, Etymonic, Campfire Audio. Classic microphone and stage headphones manufacturers such as Shure, Sennheiser, Audio-Technica and Mackie complete the offer.

My first contact with the Lime Ears product happened during the test of the second Aether R model from the top and it was then that EMIL STOŁECKI, its co-founder, briefly talked about the company's roots. Let me remind you that the business started as a two-person manufacture in Wrocław, and the official start of its activity was in September 2012. Mr. Emil is an acoustician by education, so he took on the issues of developing the sound of headphones, and KAROLINA ROMAN, with whom he founded the company, took up the art of producing "custom" bodies tailored to the listener's ear.

Yes, that’s right - "custom" ones. Before we move on to the technical description of the tested model, we must focus on what the Lime Ears headphones look like. This is a super important element of this offer, because it defines not only the company itself, but also the user. One can choose the type of finish, it can be - for example - gold flakes or silver mica points - one can apply one’s own logo, or use one of the decorative motifs proposed by the manufacturer. As the boss of the company said in the aforementioned test, as a musician, a bassist actually, he wanted to make monitors for himself, and as a sound engineer he wanted them to be both technically and aesthetically great (see HERE | PL |).

This is a "designer" stage of customizing headphones to one’s own needs. The second, perhaps more important, stage is the "sonic" stage. It's about matching the earphone outlet to one’s ear. Classically, rubber, silicone or shape-remembering foam ear tips are used for this, and these are quite good solutions.

Professionals, however, prefer to fit the tips to their own ears - and each of them is different. Instead of a soft tip, the company fixes a plastic element that repeats the shape of one’s ear. To do this, first one has to go to the audiologist and order an impression of inner part of the ear, which is than sent to the Lime Ear. There, on its basis, they make the final element, which is put on instead of silicone tips.

▌ PNEΠMA

THE LIME EARS LINEUP IS QUITE SMALL. The company offers five models: Λ lambda, Ψ psi, Model X, Aether R and Pneuma (the manufacturer uses the Greek “Pi” instead of the letter 'U'), costing in the basic version from USD 480 for Λ lambda to USD 1,800 for Pneuma. The latter is therefore the manufacturer's top model and one of the newest ones. It was introduced end of 2020.

These are IEM type in-ear headphones with a hybrid design, i.e. with four armature drivers and a dynamic bass driver with a titanium diaphragm. The company materials read:

Thanks to the 7mm titanium dynamic driver responsible for sub-bass frequencies, the low tones are clearer and stronger than in other Lime Ears headphones. […] As it is a hybrid design with a dynamic driver, we focused on dynamics. We came up with an idea that a shimmering red is to be the color of dynamics (a bit like molten lava), combined with the Seed Of Life symbol representing creation.

⸜ Pneuma – Custom-Fit, LIMEEARS.com; accessed: 10.09.2021.

The body is made of acrylic and the outlet is made of ruthene-plated brass. The IEMs are therefore light and rigid. There is a bass boost switch near the bottom edge - it is discreet, but quite easy to use. On their surface there is a symbol of "sacred geometry", which was - as the manufacturer points out in his materials - the inspiration for this model.

Sacred geometry is considered an ancient science that uses the "energy" of specific geometric patterns. Let me remind you that the American company CARDAS AUDIO, a cable manufacturer, also uses esotericism - one of their basic construction principles is the so-called "golden ratio".

⸜ DRIVERS The design is based on four armature drivers supported by a passive crossover. Two transducers are used to reproduce higher bass (above 100 Hz) and lower midrange, one, wideband one, reproduces the midrange, and the other one, high tones. A separate, dynamic driver with a titanium diaphragm with a diameter of ø 7 mm reproduces the lowest tones and can be turned off with a small switch. It can compensate for the non-linearity of the human ear, which is described by the Fletcher-Munson (FML) curves. The adjustment in the Pneuma model ranges from +3 to +6 dB, depending on the loudness level at which the measurement is taken.

⸜ VariBore The crossover is, as the manufacturer says, a "hybrid" design, which means it is probably a combination of acoustic attenuation - a combination of the natural drop of the diaphragm's frequency response and the chamber in which it is placed - and electronic components. Part of their tuning is the proprietary VariBore technique, present in this manufacturer's headphones since the Model X, i.e. from the beginning of 2019.

When we look at the headphone outlet, without the tip, we can see three holes. The smallest, with a diameter of ø 1 mm, is the outlet for the low-frequency chamber, and the next two, 2 mm each, are the outlets for the mid- and treble chambers. In the case of high frequencies, its diameter, combined with internal acoustic attenuation, provides, as we can read in the company materials, "open sound and smooth treble".

⸜ BAM In the description of Pneum we find one more proprietary solution, called BAM. Backfiring Acoustically-damped Membrane is a development similar to a bass-reflex system in loudspeakers. It uses the energy radiated from the rear of the driver's diaphragm to enhance the bass efficiency. Let us add that the dynamic woofer was damped by carefully selected open-cell shape memory foam element, which allowed to reduce the acoustic resonances inside the body.

⸜ ACCESSORIES The Lime Ears headphones are packed in a very nice cardboard box with a magnetic clasp - similar to what Sephora uses to pack cosmetics for a gift. Inside you will find another nice box, the travel Pelican Case 1015. The whole thing is supported by pieces of paper and among them one finds some candies - fudges.

The case contains headphones, a cable for them and SpinFit silicone ear tips in four sizes, as well as a set of foam tips (three sizes). There is also a small VariBore hole cleaner. The demo sample that arrived for the test did not include a 6.3 mm → ø 3.5 mm mini-jack adapter.

The cable in question was produced by PW Audio and it is quite thick and stiff. Its design is much better than that used in the Aether R model, but it also isn’t too soft and is a bit heavier. The PW Audio (Peter Wong Audio) is a Hong Kong-based company. The cable used in the Pneuma model looks similar to the "Anniversary" No.10 model and it features, if I am not mistaken, silver-plated copper conductors.

⸜ BUILD QUALITY The Lime Ears headphones were made with attention to details. Each element of their design looks well-thought-out and worked out. Their appearance is simply stunning, and the possibility of making "custom" versions is a guarantee of a unique look and the exact fit of the IEMs to customer’s ears.

▌ SOUND

⸤ HOW WE LISTENED Lime Ears PNEΠMA headphones were listened to in three different systems, against two different references. The basic system was a mobile set consisting of a Samsung A41 smartphone equipped with an external ALO AUDIO PILOT digital-to-analog converter, with the USB AUDIO PRO app.

This American DAC / headphone amplifier is a small but excellent device featuring the ESS Sabre ES9281C PRO chip, which supports hi-res files - PCM digital signal up to 32 bits and 384 kHz and DSD up to DSD128 (5.6 MHz). It also decodes the MQA signal. The latter feature was important as I spent many hours listening to music from Tidal Master (FLAC and MQA).

And the aforementioned application helps with that. It is inexpensive, and it works wonders - it become a driver for the USB. It allows you to play files in a native format up to 32 bits and with any sampling frequency, including MQA. Normally the smartphone converts everything to 48kHz, no matter what the original sampling frequency is. And it doesn’t do any favors to the sound quality... I was persuaded to buy this app by one of the HF readers, who showed me the source of the problem and I’d like to thank him so much !!!

For comparison in this part, I used two pairs of portable headphones that I have been using for years, meaning the FOCAL SPHEAR ($ 179; test HERE) and the AKG K3003 (4190 PLN; test HERE).

The second system served as a reference for me. It consisted of the LEBEN CS600X tube amplifier (PLN 25,900, test HERE) and planar-magnetic headphones, HiFiMAN HE-1000 v2 (PLN 15,000, test HERE) and Audeze LCD-3. In the latter case, the Ayon Audio CD-35 HF Edition SACD player was the source of the signal. I used a separate listening session to compare the tested Lime Ears headphones with the HiFiMAN HE-1000 v2 using the headphone output of the MYTEK BROOKLYN BRIDGE.

One of the most important functional properties of the tested headphones is a switch that activates the dynamic subwoofer diaphragm, thus enhancing the low tones. Contrary to the Aether R model, it was set to the "OFF" position for a larger part of the listening sessions. All jazz recordings from Blue Note, Prestige, Atlantic etc. from the 1950s and 1960s sounded cleaner this way, and the bass was just right. Although sometimes I wanted to add some "meat" to the music and then I turned the "subwoofer" on...

Recordings used for the test | a selection

→ SUPER AUDIO CD/COMPACT DISC
⸜ ELLA FITZGERALD, Like Someone In Love, Verve/Esoteric ESSO-90143, SACD/CD (1956/2016) w: 6 Queens of Jazz Vocal, „MasterSoundWorks”, Esoteric ESSO-90143/8, 6 x SACD/CD (2016).
⸜ PATRICIA BARBER, Companion, Premonition Records/Mobile Fidelity Sound Lab UDSACD 2023, SACD/CD (1999/2003).
⸜ SONNY CLARK, Cool Struttin’, Blue Note/Esoteric ESSB-90124, SACD/CD (1957/2015) w: Blue Note 6 Great Jazz, Blue Note/Esoteric ESSB-90122/7 (2015).
⸜ YES, 90125, ATCO/Warner Music Japan WPCR-15914, „7 Inch Mini LP”, SACD/CD (1983/2014).

→ FILES
⸜ JEAN-MICHELE JARRE, Amazônia (Binaural Version), Columbia Records/Tidal, FLAC 16/44,1 (2021).
⸜ MARIA PESZEK, Ave Maria, Mystic Productions/Tidal, FLAC 16/44,1 (2021).
⸜ NATHANIEL RATELIFF, Red Rock 2020 (Live), Stax/Tidal Master, MQA FLAC 24/48 (2021).
⸜ SUPERTRAMP , The Very Best of Supertramp, A&M Records/Tidal, FLAC 16/44,1 (1990).

»«

ALTHOUGH IT MAY APPEAR ILLOGICAL and technically incorrect, the headphones differ not only in tonality, dynamics, resolution, selectivity, but also the way they present space. This can be explained by a different angle of inclination of the drivers in relation to the ear cup, as well as the basic difference between classic around-ear headphones and IEM designs that deliver sound directly to ears’ interior. But how to explain the differences between headphones with very similar geometry? How to explain the differences in the location of instruments between different IEM models?

And comparing the Lime Ears Pneuma with any in-ear headphones, we come to the conclusion that Polish IEMs “see” space in a completely different way, shape it differently. They seem to be much closer to the sound source than other headphones. I would say that they reproduce the real situation better, that is, they put themselves in the place of the microphone. I would say this if it were not for the fact that with "constructed" recordings, and not "documents" - and these are the dominant ones and we are used to them - the setting of the microphone is only the beginning of the creation of space, because then there are reverbs, compression, effects, etc., which are equally, if not more important.

In any case, the Pneumas perform sort of "approximation". They're a bit like a magnifying glass - but not quite. Listened to for an extended period of time, they turn out to be something more. The feeling of zooming in disappears, and we begin to understand that it is not about physical approximation of the sound sources, but about their better definition, that we can better - let's stay with visual comparisons - „see” them. They are one of the most resolving headphones I have heard, regardless of a design and purpose.

All I needed were the few bars of Michael Arnopol's double bass from the second track on the PATRICIA BARBER’s Companion, the Use Me track, the first few words sung by ELLA FITZGERALD on the Like Someone In Love, beautifully remastered in DSD and released on SACD by the Japanese company Esoteric, to hear a wealth of information, lots of details, which I have not heard in such a clear way with any reference model, that is neither HiFiMAN HE-1000 v2 headphones, or Audeze LCD-3. And yet they are ultra-resolving planar-magnetic designs!

But it is not the case that the Pneumas break the presentation down into tiniest information - it is exactly the opposite, other headphones seem to do it, at least in direct comparison to the Lime Ears. The latter seem almost warm, silky smooth. In terms of timbre, they are closer to the Audeze headphones and - when it comes to dynamic designs - to the AKG K701 and Beyerdynamic DT-990 Pro (600 Ω) rather than to the HiFiMAN and Sennheiser HD-800.

The timbre I am talking about results not from the saturation of some sub-range, that is from coloration, but from delivering such an amount of information which allows for a trouble-free "reconstruction" of the sound inside one’s head. And less effort means less fatigue and, as a result, a relaxed presentation. And that's what these headphones sound like - in an incredibly relaxed, incredibly saturated and at the same time accurate way. They also show very well various types of recordings, masters and remasters, perfectly catch the transition from CD-quality recordings to the "Master" files from Tidal encoded in MQA.

The latter is important because Pneuma IEMs will probably be used most of the time with portable devices. While in the case of CDs and SACDs the switching from one version to another was audible, but ultimately not "significant", in the case of Tidal it was critical - hi-res files do not just make sense in this case, but become a "to be, or not be." type of question Everything is improving. The most important thing, however, is that the recordings sound much more natural and real.

That is why I was surprised to hear about the form of release of the long-awaited MARYSIA PESZEK’s Ave Maria album, which the label presented in a regular FLAC 16 / 44.1 file. At the time, when the biggest services give up lossy compression forever and talk about hundreds of thousands of hi-res files, the "CD" version on an audiophile service focused on sound quality seems to be an anachronism.

The more so, that the Pneuma are so resolving and present such differences so clearly. Interestingly, they do not massacre the lower quality recordings, but rather reward the better ones. Their timbre is quite warm and there is no trace of a hardened attack in their sound, which often results in a shrill sound or hard-to-bear urgency. Limea Ears are like aristocracy, at least the one imagined by us, descendants of peasants (by saying 'we' I mean, obviously, myself, not you :). Shiny, colorful, ruch, without any mundane problems.

The bass with the tested headphones is not as fast and as resolving as with planar-magnetic designs, but on the other hand it seems more colorful, better filled. This is why the voices of the singers were so incredibly natural, whether it was the aforementioned Fitzgerald, or Rick Davies and Roger Hodgson from the 1990s compilation with the greatest hits of SUPERTRAMP, or finally the perfect NATHANIEL RATELIFF from the concert album Red Rock 2020 (Live). In neither of these cases I needed the support of a "subwoofer" driver.

I sometimes reached for the switch when dealing with electronic music. However, using the "subwoofer" blurs the presentation a bit. It gives a "kick", but at the same time shifts our attention from spatial relations to timbre. And these are headphones that, without imposing a bright timbre - because they are not bright - go deep between the sounds, between the instruments, so you do not need to help them in this way.

▌ SUMMARY

The AETHER R MODEL BY LIME EARS surprised me in every respect - when it comes to the idea, artistic design, make and finish and finally the sound. This is a model that puts the vast majority of other IEM headphones in a difficult position. Not because it is absolutely the best, but because it is so versatile, so well “arranged”, so pleasant to listen to.

The top model is better, even much better, that is, it belongs among the absolute top models. It can compete not only with in-ear headphones, but with any headphones, including planar-magnetic ones. But it is different in its character than a large part of the high-end headphones, including the Aether R. While the latter are very effective, dynamic, even "lively", the Pneuma model doses everything in a better way, more carefully. It does it like a pro who doesn't have to prove anything.

Their tonal balance is incredibly well set, and the resolution is above average. They seem to sound in a dark, warm way, but this is an illusion to which we succumb due to what we are used to by listening to music with other headphones. The space with them is incredible in its density, but they also show the sound close to us - although in fact they bring US closer to the sound. This makes binaural recordings better than with any headphones I have heard, and the classic ones, including mono ones - extremely pleasant.

It is worth knowing, however, that large around-ear headphones create larger phantom images with a better defined shape. They also show events farther away from us, which makes them sound more like what we hear through loudspeakers.

Ultimately, the Lime Ears Pneuma are one of the best headphones I have ever heard, regardless of their design or price. And all that with standard, silicone elements that couple them with our ears. Having said that, I already have an appointment with the audiologist to make an impression of my ears. I can't live without these headphones - that's why I ordered them for myself. ■