Vesselin Teoharov on himself. "My memories start in 1982 with Dire Straits and Communiqué. 'Small people' were playing music from inside some mysterious spinning black disc. Being four years old and not understanding that we were listening to LP, I wondered how it was possible that those small people could play so loud? Now I know all those 'people' very well and the question has become: can they play better? I’ll never stop wondering. Looking for an answer then, I started fiddling with a few of my father's radio cassette players by disassembling them to pieces. The research began. Then came the schools, the books, the CDs and the joy was all mine! During all those times the music was my guiding light. I’m still not sure if it was the music itself or the artists playing it but in any case, I wanted to listen to the music as it was meant to be. My first setup was DIY and so were many that followed. Not one was good enough. Then came the job, the salary, my new system from a big fancy audio store. But no matter how hard I tried or looked, I was not able to settle down and fully enjoy music with commercially available hifi. I felt that something could be improved, that something more had to be served to the listeners to trigger their deepest emotions.
 

"Then came the education, the possibilities, then Teoharov as a piece of my art. The Teoharov brand is developing as a separate part of my company which has operated for over 25 years in the field of electronics and telecommunications. We are specialized in the design and planning of broadcast networks but also in the production of RF amplifiers and transmitters. All that knowledge and practice accumulated over many years is now inseparable and stamped into our high-end products by implementing standards and principles of truly top electronics. It all began when I built a hifi amp as the subject for my final high-school exam. Later I studied loudspeakers during college and my Master's studies. Yet again as cherry on top, I built a high-end amp as my final master's thesis project. Passionate learning, research, prototyping and listening were all part of that process. For more than 20 years now, Teoharov produces and installs custom high-end audio systems by enrolling many diehard audiophiles and music enthusiast. A wide array of different customers shares one common denominator: huge satisfaction with our products. A year ago I decided to commercialize two of my products to make them available to everyone in a small handcrafted series. The first one is the Model 1 monitor which uses a premium ScanSpeak Illuminator tweeter and ScanSpeak Revelator mid/woofer in a two-way configuration complete with stand and absorber. The second is the floorstanding Model 2. Both are completely handcrafted with solid not veneered Walnut panels—other wood types upon request—finished in organic oils, damped with pure lamb wool, connected with WBT, wired with Van Den Hul plus acoustic absorbers made of pure 20mm glass and aluminium. In short, nothing but the best."


On the review pair. "These are prototypes and the first ones. When I placed them on the DB Schenker lorry, there was a moment when I felt as though I was sending my son abroad for college. I got that emotional. Few details make them less than perfect. There are some developmental mistakes now solved for production. For example, the border between wood and black body should have been a 1mm silver strip. Also, the black paint changed to a fine surface polish. I added the toggle on the back terminal at the end of our auditions to adjust the presence region to taste. The range is +0.7 to -0.6dB, with 0.0dB in the centre position hinged at 2.7kHz. The production marking will call it 'upper band level'. The final aluminium plinth plates became 6mm instead of 10mm for aesthetic reasons and the top plate won't have your prototype's screw holes."


On the general Model 2 concept. "Probably the first thing I should say about this speaker is that it is unconventional. The whole idea at the beginning was not to be unconventional for its own sake but to, without compromising performance, use my knowledge and obtain more power, sensitivity and bass extension. The final destination I meant to reach was performance without distortion, with high realism that made the instruments and stage as big as they actually are. Looking out from behind conventional small midrange drivers is the hardest job in a club so I meant to enlarge that area to ensure a proper place for everyone on the virtual stage. Now there are three paralleled mid/woofers. The two-way concept arose because the first crossover of a three-way, between bass and mid, is where the human ear is most sensitive to especially phase distortion. No matter how well you execute your filter and budget for it, it will never be better than not having that crossover in the first place. My final topology pursues Einstein's mandate of as simple as possible but no simpler. I only use air-core coils for their lower distortion from ferromagnetic hysteresis and an adopted Bessel transfer function on each slope because their reconstruction in free space is almost a 1st-order configuration. The tuning of the Helmholtz resonators [ports - Ed] is also gentle as the slope begins below the drivers' lower frequency limit.


"Both cabinets are configured as a reflex box and both are supplied with the exact same electrical signal from the crossover. The difference is the acoustical filtering at the bottom edge to work in phase at the critical bass frequencies. Acoustical vibration absorbers are installed between head and bass cabs to minimize intermodulation distortion. Strain vibration from the drivers being electro-mechanic-acoustical transformers is absorbed by the plinths which elevate the speakers without rigid mechanical contact to ground. Diffraction as a common midband non-linearity is reduced to lowest levels with optimally designed sidewalls. The left and right speaker are mirror-imaged to achieve the optimum angle between listener and baffles in a straight-out position whilst the anti-parallel walls make for superior damping to obtain fine precise bass without energy storage. The time domain between tweeter and mid/woofers is compensated with the tilt of both cabinets."   
On the Model 2 specifics. "The Model 2 is a low-distortion phase-invariant 4-driver two-chassis dual-ported 2-way tower with extra-wide dispersion. Parts include the Sym-Drive Neodymium-powered 5.6cm² ScanSpeak ring radiator and three 150cm² ScanSpeak Revelator paper-cone mid/woofers, 2mm Mundorf baked-varnish AirCore inductors plus Jantzen Superior Z capacitors with direct SnPbCu solder. The filter slope is a quasi 4th-order Bessel for flat phase and amplitude response but more precisely, the low pass is a 3rd-order/8Ω with 16dB/oct. slope and the high-pass a 4th-order/8Ω with a 22dB/oct. slope. The speaker terminals are WBT-0703 Cu biwire. The cabinet walls are a MDF/Walnut sandwich with a D4 polyurethane adhesive for the head unit and a MDF/D4/rubber laminate for the bass cab with lamb's wool filler for each.


"On a 4Ω dummy load the crossover point would appear at 2'500Hz at -6dB. In free space, the crossover point operates at 2'800Hz with ±2dB linearity from 50Hz - 20'000Hz. Bandwidth at -8dB is 30Hz - 50'000Hz. Sensitivity is 91dB, distortion (measured on axis at 1W from 50-30'000Hz) is below 0.15% for 2nd and 3rd-order THD. Hookup wiring is high-purity OFC with linear-structured saturated carbon layers via 2.05mm² Van den Hul. The ports are a 26cm² pipe on the lower mid/woofers and a 15cm² tube on the upper one. Nominal impedance is 4Ω, impedance magnitude is 3.5Ω - 19Ω. Power handling is 150 watts, recommended power is 5 - 200Wrms."