Exclusive interview with the Soul man - Miro Krajnc of SoulSonic Speakers

Tell us a bit about your background. 

My father was into music a lot, he played a few instruments and had quite a large collection of reel-to-reel tapes and phonograph records and I was into music ever since I can remember as well. When I was young I would order many records from the USA, I was mostly into progressive Bluegrass back then (banjo players like Trischka, Fleck and Cloud or guitarists like Tony Rice and Mark O`Connor), but eventually I started listening to other forms of music as well, classical and jazz, or some acoustic guitar fingerpickers like Kottke, Hedges, DeGrassi or (Slovenian guitarist) Bojan Drobež, all of them are among my favorite musicians too. I really enjoy Tango music as well. My son Timi plays in one such band, honoring the music of the late Astor Piazzolla. 

My first "serious" system was built around a Kuzma Stabi/Stogi turntable, Yamaha integrated (I don`t remember the model, but it was later replaced by a Musical Fidelity B200 amplifier) and Sony APM 22 Esprit speakers.

While trying to find the source of hardness in the sound at higher SPLs, I checked the crossover parts in the Sony speakers and noticed that they had used some small ferrite core coils. At that time I had already read all the Speaker Builder and Klang & Ton magazines with great interest and decided to build myself new speakers from the ground up, using better crossover material and drivers, if possible. The first speaker I actually built was a WHD B410 subwoofer, in accordance with the Stereoplay plans, but after that I went on to build some freestanding two way speakers. I purchased some books about loudspeakers (Martin Colloms, Vance Dickason, etc), CAD software like CALSOD and AudioCAD and one of the first affordable measurements systems, Liberty Instruments' IMP. Equipped with all these goods I began experimenting like mad. Apart from the WHD sub, I have never built anything according to someone else's plans because I`ve always wanted to make everything my own way.

Throughout the years, I have analyzed thousands of commercial and DIY loudspeaker systems, observed the measurements, listened to the loudspeakers and tried to find some correlation between objective and subjective. I really came to my conclusions and preferences after listening, but many times theory would support my listening impressions.

I have tried to understand the engineering principles behind the most popular high end speakers and have learned from many renowned loudspeaker designers and their differing philosophies. 

I tried all the prevailing approaches regarding crossovers (series, parallel, steep, shallow XO orders), low frequency loading techniques (closed box, bass reflex, passive radiator, various bandpasses, various transmission lines, horns, aperiodic damping, open baffle), monopole, dipole, bipole and omnipolar radiation patterns, various driver materials like aluminum, magnesium, titanium, Beryllium, carbon fiber, glass fiber, Kevlar, polypropylene, various paper mixes (my favorite cone material), planar magnetics, ribbons, AMT , plasma (ionic) drivers, you name it. 

I spent a lot of time trying to nail down the culprit of all those nasty box resonances, but the turning point came when I experienced the sound of the Apogee Diva, the legendary planar magnetic/ribbon dipole speaker.

I knew the sound of the many great boxed speakers of that time, but this was something entirely different - I was actually shocked by their sonic realism. 

Later, I have heard some great line source (Magnepan) as well as plane source (ESLs) speakers and was convinced this was the way to go. These types of speakers seemed always much more capable of "pulling my strings" than anything else, even though I did noticed some weak spots.

To this day, the most memorable experiences I have had with any speaker types were those of the Apogee Diva, Acoustat Monitor 4, Martin Logan Request and the bigger Soundlabs. For a few years I was hooked by the sound of spherical horns and spent a lot of time building and developing them. Somehow, horns are still on my horizon.

Years ago I thought I have learned something, but after a while I`ve realized there are more questions in this field that need to be addressed. At least with speakers and recording techniques it seems we`re all still in the dark ages but the progress is evident, of course.

Why SoulSonic Speakers?

Well, for the past twenty-some years I was actually searching for a loudspeaker principle that would bring me the closest to the original event, that would, technically, be as good as it gets, that would reveal all the quality differences in the recordings, but still wouldn`t force me to prefer my music selections based on the sound quality rather than music quality. In short, it would have to enhance my listening pleasure with almost all recordings – which is quite difficult to find these days. 

So, in essence, I was completely open-minded and let myself be surprised by all these different loudspeaker technologies and I`ve put aside everything I knew from the theory, only the listening results would matter. 

The way I see it, all components should be built with the aim of achieving the highest possible transparency, but in a linear manner, without emphasizing any portion of the spectrum and by preserving the dynamics as much as possible. The natural harmonic content of instruments and voices should be preserved as much as possible too.

If there was one thing that seemed most crucial for achieving the sonic grandeur and realism, it was the fact that there is no substitute for the active (drivers) and passive (baffle size) surface area (I call it: "sound torque").

Of course, this meant my speakers would inevitably have to be large and I would have to put some effort into making them less obtrusive, visually.

At the end, of course, I don`t think my speakers are perfect, far from it, we all still have a very long way to go, but I believe they do possess a high musical involvement factor and look attractive, among other things. 

Do you feel there is a certain aspect of your speaker designs that sets it apart from the traditional planar dipoles? 

One thing I wasn`t completely satisfied with was the bass performance of the majority of planar magnetic or ESL speakers, which mostly seemed somewhat softer and lacking in dynamics. 

I have built a two meter tall planar magnetic woofer in the style of the biggest and oldest Apogee and although it sounded good, it was no match for the four 12 inch woofers in the dipole/open baffle mode. The efficiency was much lower (6dB less), with less SPL potential as well. I wanted my speakers to be pretty robust, dynamic sounding, with higher sensitivity and have therefore decided to use very light paper cones with strong motors.

What is the story behind your decision to use the ribbon, for the mid high range? 

Ribbon is one of the oldest and simplest driver working principles and it dates back to 1924 when Walter H. Schottky and Erwin Gerlach co-invented the first ribbon microphone. By turning the signal path in the opposite direction, the first ribbon tweeter appeared. This early invention was the basis for all later planar transducers like planar magnetic, air motion transformer and other Heil types that are now being developed. So, in effect, I owe much more to this early invention than to the later commercial products that evolved around it. 

As much as I loved the sound of the old tall ribbons (and newer ones), I still felt there was room for improvements. For one thing, I was really concerned about the diffraction issues of the deep cavities found in the existing ribbon designs. My ribbon construction is a very shallow, low diffraction type, with great dispersion characteristics in the horizontal plane. Additionally, I have developed a simplified type of ribbon clamping that makes ribbon replacement a very easy task. 

Do you think your current speaker range has only advantages, with no shortcomings compared to other speaker types? 

Well, the most obvious disadvantage would be of course their size and the required minimum distance from the back wall to show all their potential. Depending on the model size,I think they`re not suitable for any rooms with less than 25 square meters available. The distance to side walls isn`t critical, but the distance to the wall behind the speakers is. In regard to the bass reproduction quality, one meter seems minimum and in regard to the ribbon, some absorption/diffusion behind them is welcome. 

SoulSonic speakers aren`t efficiency champions, but even in this regard they are above the majority of planar speakers, at least a few dB, I would say. 

Of course, the new Hologramm-X is much more efficient and easy to drive, with its 95dB efficiency.

Moving on, the dipole speaker approach has one specific characteristic that I really favor over the monopole approach and that is the »sound velocity« radiation characteristic as opposed to the »sound pressure« characteristic of boxed (monopole) speakers. In simple terms, the dipoles don`t pressurize the room and ears in the same way as boxed speakers do. Their sound is much more connected with the listener through the air than through the floor and walls for instance, if you get my point? 

I think this the major difference compared to all other boxed speakers and not the »enhanced ambience« that is supposedly created by the sound bouncing of the walls, coming from the rear of the dipole speakers, like some people think. 

Another advantage is the line source characteristic of the ribbon mid/high frequency unit and although this is effective only above a certain frequency (speakers are all about compromises, remember?) and up to certain distances, it nevertheless helps to maintain a very desirable characteristic and that is the SPL from an infinitely long line source falls off at a rate of 3 dB per doubling of distance, while the SPL from an ideal point source radiator falls off at the rate of 6 dB per doubling of distance. With line source ribbon, the nearfield extends up to three times of its longest dimension, while with a point source speaker this nearfield extends only to a couple of inches or centimeters, if you will. In practice this means that with a ribbon that is 2m tall, it will maintain its nearfield characteristic up to 6 meters ( the SPL will drop only 3dB for each doubling of the distance). 

The net result of all this is no listening fatigue, even after prolonged, very loud listening sessions. 

Tell us something about the outstanding aesthetics of SoulSonic speakers. 

In the beginning, I was inspired by some historical designs, but I wanted to create something different, something that would fit into all environments and that would act as a work of modern art, to be environment friendly, so to speak. The IMPULSE and WAVE models reflect this, I guess. However, with the IMPACT and BEAT, I wen`t into uncharted territories but both speakers were still primarily built upon the acoustic ideas. I wanted a controlled room power response, with less side wall excitation. 

With the Hologramm-X and smaller Hologramm-S, I wanted to create something fresh and elegant, parting with the past, while still retaining a strong acoustic foundation.

My first speakers weren`t all that elegant, but eventually I have improved my designing skills and the results speak for themselves, I think.

As soon as I decided to use cone woofers and knowing that I need a certain baffle to prevent too early dipole cancellation, I decided to make the speakers a little less bulky by utilizing a stained glass baffle, which is being supported by the ribbon pole and doesn`t have a direct contact with the woofer baffle.

I don't like square shaped speakers, smooth curvatures speak to my sould much more intensively and all this shows up in my speakers. Since I have no formal education from this field, I have no deep theory behind it, it is just the way I see speakers. 

Usually, people tend to hide their speakers or integrate them into the walls, but my speakers actually don`t need any excuses for being put right there in the middle of the room...OK, just kidding. 

Regarding the visual aesthetics in general, I believe nowadays, a product should be as good as it gets in every aspect. I know the majority of audiophiles are only concerned about the sound performance which is of course the main factor in regard to musical enjoyment, but if the product could be made refreshingly good looking and (!) good sounding at the same time – why not make it aesthetically pleasing? Does it have to be ugly to suggest serious performance ? 

I would like to help change that old prejudice that if a piece of audio gear looks beautiful, then the manufacturer must be covering some serious performance flaws, compensating them with visual aesthetics. 

I mean, these things aren`t mutually exclusive and there is an increasing number of components that prove my point. 

Tell us something about the IMPULSE model. 

The IMPULSE was the first model I came up with. It was the result of my quest after the speaker that would satisfy me personally in every possible regard. 

Perhaps at this point I should mention my listening preferences: I love the sound to be immediate, alive, dynamic, spectrally balanced, with tall soundstage and great transparency. I dislike the pin-point focus of small point source type bookshelf speakers but I do like a holographic type of imaging and the difference between these two are huge. Life-sized and pin-point sized are not to be confused. To enjoy live musical events in terms of audiophile vocabulary, would be missing the entire point of the musical message anyway. Spectral balance, natural harmonic content and micro/macro dynamic behavior are much more important, I think and when present, the musical involvement becomes much deeper and stronger.

So, in absolute terms, I prefer the sound of bigger speakers, simply because they are more able to move the necessary amounts of air that live music events demonstrate to us so effectively. In this regard I consider even my speakers too small. I mean, the musical instruments have large surface areas that barely move and trying to mimic their sound by means of small domes and cones is...well, you figure it out. 

With small speakers you get high surface loudness, which is unnatural and with large speakers we are moving towards low surface loudness, which shouldn`t be neglected if we truly aim for at least remotely realistic reproduction of music. 

Hearing the music as well as feeling the waves through our bodies, makes for a thrilling experience. The music should move us on several levels and when it does, the end result is astonishing.I highly doubt the ultimate goal of any composer or musician is to make us fragment their musical works into tiny pieces and intellectual pondering.

What happened at THE S.H.O.W. and CES 2011? 

Well, it was a great experience, to say the least. In the past I went to many Audio Shows and from my memory, the people would mostly listen, only sometimes expressing their impressions to the exhibitors. In my case, I was pleased to find out that the majority of visitors felt the need to express their highly positive remarks about our setup. Most of them said our sound was one of the best at THE S.H.O.W. and CES, while some felt it was the best of the whole event. 

One visitor was very keen to find out how my speakers would perform with the WAVAC electronics and, with help from Mr. Takuji Sudo, I was able to get the amazing WAVAC preamp and 60W monoblocks for the entire show period (WAVAC Audio Lab PR-T1 preamp and MD-805mkII monos with external power supplies). The overall sound quality owes much to their electronics and I would like to use this opportunity to express my gratitude to the entire WAVAC crew and their US distributor, Mr. Jonathan Brown. 

Most of the visitors felt SoulSonic Impulse represents a new breed of planar speakers, with enhanced dynamics and great bass reproduction, along with all of the qualities only a true ribbon can offer. 

I got numerous enthusiastic remarks even from the competition, which is really satisfying. 

What does the term HIGH END mean to you? 

It means a quest for the highest quality sound reproduction possible, no more no less, – simple as it sounds. Of course, all we can do is only approach it as we will probably never fully reach it, but that`s the beauty of all creative processes – there will always be something to improve upon. 

Your first customer? 

...was a passionate music lover from the Slovenian coast. He is a very experienced listener and he recognized instantly all the virtues of my speakers that I also believe are hard to overlook. 

His former speakers Magnepan MG 20.1 were driven actively and so are now his IMPULSEs. 

Is SoulSonic audiophile oriented company? 

I am trying to reach a broader audience. Many people who otherwise have a good taste for many things in life, aren`t even aware there is such a thing as High End audio, but of course it takes some effort to reach them and this is probably the most underrated group of potential customers. 

What is you view on tubes vs solid state? 

Well, I really like the combination of the two. I have heard great and bad examples of both camps, but up until now none of my previous experiences suggested I should avoid any of the two types. Tubes in the preamp stages (especially DHT) do seem to make a lot of systems sound very alive and also transparent, but I know the solid state approach can give extremely good results too. 

Do you think the ultimate transparency, dynamics, and musicality can be brought under one roof? 

Yes, I think this is possible, these things aren`t mutually exclusive but it takes an effort to achieve all this under one roof. 

I think a true achievement is if a component (or a system as a whole) is able to sound utterly transparent, refined and alive at the same time. 

Is high quality more affordable today? 

Yes, I do believe it is, never before have we witnessed so many affordable audio components to choose from. 

What kind of people you see as potential buyers of the SoulSonic speakers? 

I think those that are after the highest sound quality will represent the majority of customers. 

I cannot say much about those that value aesthetics as well, since everyone has its own particular taste, which is understandable. With my speakers, you either fall in love with them immediately or...hate them - there is no middle ground.

Will you strictly stay in the speaker production, or you're planning to expand with other components? 

I have no other plans presently. 

What holds the future for the SoulSonic? 

I think the future is promising and will be very exciting. I have also become involved with audio design and complete audio&visual design for other companies like Ubiq Audio (Slovenia) and Natural Sound (Poland) and these companies enabled me to explore some of my other ideas, for which I am very thankful to be given the chance.

Would you like to tell something to our readers? 

Enjoy the music as much as possible and try to be a part of solution for this planet, acting consciously in all aspects of your daily lives.