Raal "Original 140-15D" Ribbon Tweeter with Amorphous Core (Pair)
Raal "Original 140-15D" Ribbon Tweeter with Amorphous Core
TRANSFORMER: The impedance matching transformer is made to transfer the real power without distortion. Not just the shaped noise signal for power measurement methods, but real high-power signal peaks can be transmitted to the ribbon, which preserves the natural dynamics recorded. The primary inductance of the transformers in RAAL ribbons is set to a value which corresponds to the second coil of 4th order L-R high-pass filter at the appropriate cut-off frequency, depending on the model in question. Recently, we finished development of Amorphous C-cores application in our ribbons. Some years ago, we were the first to introduce large gap approach in building ribbon transformers and now we are the first to use AMCC's in ribbons for absolutely uncompressed high power transient transfer and, at the same time, even further improving already the best low-level performance in the world today, by decreasing the width of hysteresis compared to HF ferrite cores. For direct coupled tube SE-ribbon, we succesfuly developed 175:1 ratio, -3dB at 120kHz Amorphous C-core transformers that can carry DC idle current of SET. Impedance conversion is about 30000:1, bringing the 0.1 Ohm ribbon up to 3kOhm, good for plate loading of most triodes in HF.
Size matters. With surface of 21 sq. cm (3.25 in. sq.), super-light 22 mg flat foil, deflector pads, homogenous magnetic field, it represents the finest in today’s mid-high transducer design. Many other details in its construction serve as tools to achieve the flattest possible frequency response and fastest settling time. Its fast and accurate. The main difference is that, contrary to other ribbon drivers, it recreates the spherical sound wave, although it is a straight line source, so the high frequency range is not emphasised and “beamed” to a vertically very narrow space.
Bad directivity characteristics is very audible, like constant presence of sound system in front of the listener, as the brain registers the changes in sound field with small head movements thus inducing the listener to use effort to be very still while listening. Also, too directive speakers, tend to provoke just a few of listening room’s reflections, making the needed diffuse sound field in room deprived of high frequency components, which is another problem to our brain. Real instruments don’t behave that way, so that should be recreated as much as possible. 140-15D does just that, it makes almost semi-spherical sound wave, like life around us does.
Its ability to produce very high SPL with no audible distortion while keeping the minute music details revealed without any effort, brings natural character of the instrument played into the listening room, with such a quality of sound that upgrades the perspective of a listener to a participant in an event that happened somewhere else in time and place.
It comes easily for the 140-15D to "fool" the human brain in such a way that, all of a sudden, makes everything sound right and just as it should. The brain has no option but to interpret that there are real living people playing real musical instruments, playing in the very room in which, a millisecond ago, contained nothing more than your stereo system. The sensation of hearing "natural" sound is overwhelming. The exact size of all the instruments and vocals, their perfect position within the sound stage, and the clarity of air between the instrument's positions are all instantly recognizable…
For measurements, drawings, crossover and more, please download .pdf datasheet here (1,0Mb)
FEATURES:
Special FLATFOIL® pure Aluminium ribbon
Special SYMMLEAD® low inductance signal path
Special EQUAFIELD® NdFeB magnetic structure
Special “non-wave-guide” INOX front plate
Exceptional vertical dispersion
Super-fast settling time
Flat frequency response
Low nonlinear distortion
High signal power handling
Highest reliability
SPECIFICATIONS:
Ribbon material: aluminium
Ribbon dimensions: ( 140 x 15 x 0.004 ) mm
Ribbon mass: 0.022 g
Ribbon area: 21 cm sq.
Gap induction ( mean value over gap width): 0.51 T
Frequency response: 500 Hz ~ 100 kHz
Sensitivity: 95 dB / 1 m / 2.83 V
Impedance: 8 Ohm
Program power handling: 200 W*
Tweeter dimensions: 180mm tall x 90mm wide
*Recommended crossover: 4th order L-R @ 1600 Hz
