Colibri Labs Electrum SE Signature review

I’ve already reviewed Electrum loudspeakers and their performance was really inspiring. They received Mono & Stereo Highly Recommended award for their unique ability to render music with massive, thunderous attacks and captivating sound performance. 

Siniša Kraljić is very intriguing person and one of the most recognized Shiatsu-Master with impressive clientele extending from who’s who in the Croatia’s musical world, entertainment business, sports and politics. He’s among the most determinate person I’ve had pleasure to meet and his positive energy radiates with unique and highly potent aura.

Colibri Labs was established in 2007 after the years of experimentations and research in ultra high-end audio concepts. Siniša managed to transfer his experiences from the healing and understanding of the energy transfer into his speakers and cables. On my last visit I’ve also had a chance to hear Guru Extreme of audio cables that are made from copper, silver and combination of gold/silver with special geometry and quite few unique design approaches. They are something special, but more about that in due time…


Colibri Labs Electrum SE Signature pushes the boundaries even further then the revised Electrum. It clearly took a lot of experimentations with materials and voicing of the speakers to design and finish these speakers. Result is above my expectations….

New Electrum SE Signature vividly reflects Siniša persona. Unaltered, pure energy transfer that goes beyond its size. They acts like a bigger three way floor stander speakers with the one of the kind ability to handle dynamic shifts. Due to the special construction of the speaker enclosures, that hides special modular compartments Electrum SE Signature acts like a fine tuned musical instruments that can handle thunderous attacks and minute changes with utmost ease. I like and love to play loud and push the gain to the max, especially with acoustical, live recorded music. Such projection of micro and marco dynamic is not easily handled by any usual dynamic speakers and Electrum SE Signature stands out by far. 

Almost mystical Kastal where Colibri Labs reside
Each of the speaker is coated with twelve layers of special coating, that is used for the luxury boats and yachts. This process adds to the already rigid chassis and deals with the unwanted resonances in a highly controlled way. 

The review model was finished in beautiful black piano color that really gives a luxurious feeling and multiple layers of lacquer create a stand out effect.

It takes two and half month to finish each pair of the Electrum’s. Special type of fiberglass rowing mat is combined with unique wooden mixture construction, that gives the speakers extreme rigidity. 


I really didn’t expect such a performance shift from this upgraded version. Sonic performance puts Colibri Labs Electrum SE Signature speakers on the plane of much bigger there way floor-standers with sound being reproduced with the fanatical, dynamic extremes. This are by no means typical dynamic speakers. Period! 

The way they can transcribe the music and especially classical and acoustical recordings put these gems on the throne of big boys. Electrum SE Signature ability to render pure, raw musical energy was impressive to say politely. 

I was really inspired by Siniša’s collection of reference discs being used for the fine tuning and even more with the music selection, closely correlating with my taste. Each new speaker prototype must undergo painstaking listening test with more then 70 selected albums!

One of the instrument Siniša is using to test the high frequency
You can only assure the reality check with one and only true reference musical material and this is un-amplifed, acoustical instruments being recorded in natural spaces. All other produced attempts simply falls into the realms of unknown. Electrum SE Signature speakers can handle all the music, but especially with classical and acoustic music they acted more like a mixture of horns, ribbon, dipole and electrostatic speakers then typical dynamic speakers. Distinctly this Siniša’s creation expose both legendary and contemporary musical twist and manage to highlight the the almost forgotten art of discovering hidden elements in beloved music albums.


As mentioned above, Siniša uses impressive collection of music to fintune his speakers. Each speaker must perform over the wider scope before making it into the working concept. 

This is where one of the most important processes happens. In order to get the voicing right, Siniša literally spends hours, days and weeks in finding right combination of materials to ensure the right sound. It might be easy to achieve a certain aspect of the sound, yet creating the loudspeakers that can play full range of musical genres is never an easy task. 

There are different type of materials, that can be used for speakers enclosures, yet wood still dominate when it comes to the natural tone, timbre and color.  And still! Its not at all easy to get everything right properly balanced with wood and mixture of materials. In theory, for example, the aluminum speaker enclosure can easily ensure rigidity and stiffness that might not be lightly to achieve with wooden structure. Wood by default is a resonant material and getting things right pushes speaker manufacturer into the realms of luthier, where selection of the wood and “tuning” plays the utmost important roles. 

And this is where Siniša crazy attention to detail, unusual determination and focused mind comes to play. 

There is no place for brutalist audio architecture in Electrum SE Signature. But, they can take the brutal audio force with firm elegancy. Dealing with massiveness of complex and loud musical material demands different takes and this is where speakers from Kastel shine…

One thing I usually instantly spot with typical dome tweeter in use is the inherited distortion signature, that sadly even our industry seemed to have embrace as de facto. With Electrum SE Signature there was an absence of such imprint and that was more then a pleasant surprise. 

I’ve told Siniša how normally typical tweeter would melt under such sound/power pressure when he played music extremely loud. He just smiled, while mentioning quite few of the “kaput" twitters. Yes, Electrum SE Signature tweeters are modified in such way, that even prolonged and powerful signal cannot destroy them. 

Any wrong do within tweeter range is at once evident with any type of metallic instrument, hi-hats rides and cymbals. Ribbon is still the king when it comes to the utmost rendition of highest spectrum, with compression waveguide tweeters coming close and with few exceptions (like with Elctrums under the test) even dome tweeter can show their real potency. 

My best friends with any review are my listening notes. Going through them always helps with the needed red line focus that can establish a safe ground for any objective conclusions. So…

Electrum SE Signature managed to reveal music in un-forcing, sublime and engulfing way where tempo was never sacrificed for the sake of sounding pleasant or fake. Their ability to lock with music is unique and SE Signature’s never failed to loose authority at any given musical material. Even with the enormous crescendos everything kept in control and well paced. 

Keeping the movement in classical music spot on without going into overexposure of particular attributes is something that many of the speakers are struggling with by default. This calls for much more investigated behavior of the materials and their reaction to resonances and micro vibrations. In reality this means heck a lot of R & D and unavoidable HOURS of listening time before getting it right. Back in the golden era of speaker designing such process was mandatory even for such giants as Altec Lansing and their engineers. These day, sadly many speakers are designed with help of CAD and then just quickly checked via signal waveforms. How can one expect the believe sound outcome from such scenario? Its an illusory patch that is killing our industry rather then help out…

Colbiri Labs Electrum SE Signature moves away from the trend of hyper open sound, where artificial detailing become an epicenter of performance. At the end of the day, I can understand that this could address particular audiophile daydreaming, but it really cannot relate with the way that music actually sound like.

SE Signature correspond to the natural sounding bass, mid and upper midrange as it does with the highs. Nothing is overblown. Sonic outcome is a result of strict orientation from the start. Siniša managed to infuse the coherency/linearity as primary focus where nothing sticks out of the frequency spectrum. SE Signature speakers are acting in preserving way rather then dissecting it. That is a compliment worthy of highlighting for good!

For example Some of the ECM recording are not the easiest material to reproduce. You’ll even find people that think they carry to much of Mr. Manfred Eicher DNA. I beg to differ. My inner sensors light green with some of the familiar ECM material where I could easily sense the atmosphere, acoustical space and most importantly being affected with the music in a grand way.

Siniša loves the music and keep his reclocking always at femto second importance by visiting live musical events and inviting real musicians into his home. This is part of his modus operandi and it shows when the music start flowing out of his beloved creations. 

Colibri Labs Electrum SE Signature speaker are not speakers that would bow down to any particular genre, but will show their real mojo with acoustical and live un-amplified music. At the reference level, this is what matters and can be called upon objectiveness.


Electrum SE Signature radiates with the positive energy exchange and points towards clear synergy between the Siniša Kraljić mindset and his beloved speaker creations. I’ve gave the pun intended remark how Electrum SE Signature vividly represents the man himself in a complete same way. Small, and of pure sumo force embraced with the timeless Zen wisdom :)…

Electrum SE Signature reflects with something special. Not too often product like this comes across. I’m always trying to stress out how the end creation mirrors the persona behind the product, his values, understanding of the music and non the less passion and love. 

Electrum SE Signature encapsulate Siniša’s close connection with the understanding of the energy on a bit different level, that we’re used to. His unique nature and given talent helped him with the creation of these rare speakers, that manages to carry subtle musical message and energy on the very different plane. 

I can lay down my listening experience only to some degree. In order to fully appreciate the Electrum SE Signature one must  hear them playing and meet the person behind. Those in a search and on the quest for normal size dynamic speakers, that can transcribe music for what it is, should put Electrum SE Signature on the short list. They can really bring something special. Electrum SE Signature emits pure energy transfer, that in right system instantly lock one into the music. They also act like bigger boxes and without trapping the sound inside of them. Sound/energy should always be distributed proportionally and Siniša’s loudspeakers are designed from ground up in such way.   

In the era where more and more people are searching for something different, unique and bespoke, Electrum SE Signature’s comes as a very different players. They embodies Siniša’s life longs passion and almost obsessive quest for perfection. Coming to the level of such is no quick plan and it takes years of determination and focus.  

It was impossible not to get hooked by the sound and performance of Colibri Labs Electrum SE Signature speakers. From what I’ve been exposed to ensured them the Mono & Stereo Upper Echelon Award for the one of the kind ability to render music with the grand portion of reality and especially with emotional impact that still lingers with me.  

Colibri Labs Electrum SE Signature speakers are not for everyone. As usually envious minds and ever wise certain audiophile type of commenters will never managed to appreciate the creations. True gems are usually hidden from the public eye and cherished by those for whom music represent something more then just ordinary mortal audio transmission. 

Text: Matej Isak


TYPE: 2 way - bass reflex
IMPEDANCE: 8 ohm-minimum - 6,7 ohm 
FREQUENCY RESPONSE: 40 hz - 30.000 khz, 
WEIGHT: 56,5 kg/per speaker
CROSSOVER: Jupiter/Duelund capacitors


Colibri Labs
Rubeši 137