Directional bass? Low bass propagates omnipolar. That means equally in all directions. The result is that we hear it more than once. First we hear the direct sound which hits our ears without bounce. Next we hear—whatever comes first—the ricochet off the side or front walls, ceiling or floor. Finally we hear the last reflections from the farthest boundaries.


Depending on involved time delay, our ears either sum all this data into one, albeit with slightly blurred edges; or our brain processes the late signal as a ghost aka room-induced reverb/echo. One look at the Bulgarian woofers tells us that they do things differently even from generic open baffles. Those fire the sound's positive-going front wave at us, the negative-going rear half at the wall behind them. Destructive interference between both creates a null at the baffle edges, then reduced output at the sides [centre graphic below]. Weaker lateral output logically diminishes the strength of sidewall, possibly even ceiling/floor reflections. Less room interference equals cleaner less lumpy bass of reduced ringiness. That's very useful. Think free/invisible room treatment.


Team less echo (and no box!) refine that recipe. Facing their woofers at each other does some useful things. It lowers their resonant frequency to increase bandwidth and output. It raises radiation resistance for higher pressurization and superior cone breaking power over lossier standard OB woofers which face an entire room's cubic air volume.
 
Note the cover seals across the woofer baskets.
340 litre sealed box, FS 24Hz
1x1m² open baffle dipole with fig. 8 pattern
72 litre Ripol, FS 14Hz, equal distribution of frequency content

Ripol is an enclosure geometry patented by Alex Ridtahler which controls dispersion pattern, increases radiation resistance and lowers its driver's resonant frequency, an effect maximized with smaller cabinetry. Unlike the spherical radiation of the sealed subwoofer at left or the symmetrical fig. 8 pattern of a classic dipole in the middle, a Ripol radiates as an asymmetrical quasi dipole. All three
models used the exact same 40cm woofer. Note the change of resonant frequency between sealed box and Ripol loading.


Without any enclosure, each Daydream woofer becomes a close-proximity wall for the other. Enter two further wrinkles. First, the rear brace seals the slot between the woofers. No front-cone output escapes in the back. The reverse applies to the rear wave. Covers across the baskets in front of the baffle seal off the back wave. It only escapes behind the baffle where covers are missing. It's an elegant take on the Ripol® concept whose general radiation pattern shows above right. For what the Daydream's exact pattern of directional bass looks like, we'd need Svetoslav. Clear regardless is that the Daydream goes beyond standard dipoles in woofer control; extension for equivalent driver size; and minimization of boundary effects. Relative to six midranges, not only does mass paralleling increase output for reduced excursion requirements/lowered distortion. It also ratchets up sensitivity, from probably ~83dB for a single unit to 91dB for the lot. Finally, the combinant surface area of such widebanders all the way up into the treble promises a more linear power response vis-à-vis the big bass drivers, making the Raal ribbon a pure super tweeter. Clearly there was more to the Daydream than met the casual eye. Thinking about it made me very curious to hear them.


But first, a bit more background from Svetoslav. "Dimensions are 147 x 42.5 x 7.5cm HxWxD. Weight is 36kg. As a 3-way system, filter frequencies are 400Hz and 4'000Hz, with a 1st-order filter on the tweeter and 2nd-orders on the mids and woofers. An impedance corrector means that low-power SET have no issue. The bass alignment is the world's first no-volume Ripol patented by us. We eliminated all enclosure volumes for very powerful but easy natural bass without any colouration, standing waves or port chuff. With our dipole upper section, it also makes for the first speaker which combines a Ripol/dipole in one body. For hookup wiring concealed in the baffle to be invisible, we use special flat Japanese cables of four-nines CCFC copper. For the heavily modified American woofers, we use German CCFC copper cables with silver coating. This combination took thousands of hours of testing and measuring to arrive at. On demand, we can offer external wiring which can be changed/upgraded at any time. The crossover is designed to account for this option.

In-room response

Impedance & phase

"The baffle can be painted in any colour to the client's wishes. Standard is a clear semi-gloss lacquer over Walnut stain. We can even produce the baffle from synthetic stone and in many colours but not only would this drastically raise the price, we don't think it's sonically ideal. Our name and marketing show dedication to nature and the environment we live in. Our eco orientation is visible in all our goods. We use natural materials like farmed solid wood or Ply, environmental friendly bio oils and paints. We believe that natural materials not only look good but sound better. Four years ago several specialists joined rank to develop audio products. There's me with a master's degree in finance but acoustic and audio designs have been my hobby for already 15 years. Mr. Radev is our electronics engineer with more than 25 years of experience in audio design. Our chief carpenter Mr. Dimitrov is one of the leaders of our country's carpentry union with more than 20 years of experience in his field. His last masterpiece was a wooden retro car. Mr. Nikolov is our specialist in modeling and producing our drivers. We also work closely with Raal owner Mr. Radisalvjevic who produces our tweeters and helps solve design issues. All of us share the same passion. We like good music and quality sound. I'm the Ecobox CEO. Today we are equipped with modern CNC machines, 3D printers, measuring and computerized equipment for R&D. We prefer to run our main production hands-on, thus more than 80% of our products are hand-crafted. We build exclusively to order to personalize each product to the client's wishes."