RAAL

Duelund Coherent Audio is proud to announce that we have been appointed distributor of the famed RAAL Ribbon products.

These gems are used by quite a few of our customers, so the match up seems logical.  Please contact us for pricing and further details.

RAAL 140-15D Ribbon Mid-High

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 mush 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…

Enough said. You must hear it to believe it.

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*
– *Recommended crossover: 4th order L-R @ 1600 Hz

, and , are registered trademarks of RAAL advanced loudspeakers d.o.o.

RAAL 70-10D RAAL Ribbon High Frequency

True ribbon drivers are well known by their ability of exceptionally fine rendering of the details in music material. They work in a different way than conventional dome or ring HF driver, relieved of all the excess baggage, so to speak, and they do their job better than anything else, regardless of the price tag. No domes, rings, suspensions, coil formers, glues, damping material, not even the lacquer insulation on the wire of the coil. No heavy plastic carrier foils, like in cheap quasi-ribbons. Only 0.004 mm (0.00016 in.) thick aluminium foil, immersed in strong magnetic field. It serves as all the moving parts mention above.

Tremendous acceleration of air is available with RAAL 70-10, more than 13000 G, and in less than 200 microseconds after, that air is stopped. That brutal controlling force combined with the smoothest response available and bandwidth of 100 kHz, can ensure you that the weak link in any system equipped with it, will not be the HF driver.

It will show the differences between the electronics or cables without any effort by the listener. The better the electronics chain before it, the better the sound will be. The sound? Well, some people still can’t believe what they can hear with it, for the fist time ever, in their well known music material. That comes as standard with, pretty much, all true ribbons, but the effortless recreation of real dynamics, and amazingly high SPL levels for a ribbon of that size, was not known before RAAL 70-10. It doesn’t get intimidated by the big amplifiers. If you have clean power, feed it to the little fellow, and you will be stunned by all the music you have, presented in another dimension of reality. If you don’t have power, and/or you don’t like it, then discover the abundance of detail and true colour of any instrument played in a brand new, engaging manner. Yes, the best quality of HF region, and real, breathing, micro and macro dynamics gives a totally new sense of what the musician(s) wanted to say. It will make you forget that the system is in front of you. The music will come to life.

For measurements, drawings, crossover and more, please download .pdf datasheet here (1,1Mb)

FEATURES:

– Special FLATFOIL® pure Aluminium ribbon
– Special SYMMLEAD® low inductance signal path
– Special EQUAFIELD® NdFeB magnetic structure
– Special “non-wave-guide” INOX front plate
– Super-fast settling time
– Flat frequency response
– Low nonlinear distortion
– High signal power handling
– Highest reliability

SPECIFICATIONS:

– Ribbon material: aluminium
– Ribbon dimensions: ( 70 x 9.5 x 0.004 ) mm
– Ribbon mass: 0.0075 g
– Ribbon area: 6.65 cm sq.
– Gap induction ( mean value over gap width): 0.62 T
– Frequency response: 2 kHz ~ 100 kHz
– Sensitivity: 92 dB / 1 m / 2.83 V
– Impedance: 8 Ohm
– Program power handling: 150 W*
– *Recommended crossover: 4th order L-R @ 2800 Hz

, and , are registered trademarks of RAAL advanced loudspeakers d.o.o.

About RAAL Technology in general:

In an effort to recreate a sound that happened in some other place, in some other time, audio engineers are constantly trying to find the best means to record and reproduce the sound as exactly as possible. If we could have absolutely accurate replica of recorded sound at the end of an audio equipment chain, than the sensation that we would have, would be the same as we actually participated in the recorded event.

Of course, absolute accuracy is not possible. Fortunately enough, it has been proven that it takes a certain level of reproduction accuracy to make the human or animal ears experience no difference to original. Impressive achievement, but with ridiculously expensive and impractical laboratory equipment and conditions.

Our goal is to bring the most of that experience to everyday life.

Since RAAL was making various kinds and sizes of custom true ribbons for more than a decade, we could see through the years of experience, what are the biggest disadvantages in using them in high-end systems and how to solve the existing problems.

EQUAFIELD® technology: The magnetic field in RAAL ribbons is homogenous. Regarding the width of the gap, it is designed to have the same strength at the ribbon edges, as well as at the ribbon middle portion. It reduces the stress at the ribbon foil dramatically. The distortion, too. To get the precisely shaped field, through the gap width and depth, we’ve extensively used the FEM and BEM magnetic circuits analysis software. In order to obtain such a field in real magnetic circuit, very strong NdFeB magnets have been precisely machined, prior to magnetisation, in very special shape. Making the magnetic field homogenous, sacrifices the strength of it, but efficiency should easily be changed for low stress and low linear and nonlinear distortion.

FLATFOIL® technology: Homogenous field has one, much more interesting result and that is the possibility to use non corrugated, thin, no-excess-weight-sandwich, flat aluminium ribbon. We are using just slightly structurally shaped pure aluminium foil, of just 0.004 mm of thickness, to yield the best possible performance. FLATFOIL®, although very thin, is much more resistant to high signal input, and unable to go out of optimum magnetic field, thus providing the non compressed dynamic output and much lower distortion at high SPL output, achieving the dynamic capabilities of horn loaded drivers with incomparable neutrality.

SYMMLEAD® technology: Very important part of signal handling is its path to the ribbon ends. Almost all of today’s ribbon drivers are using the layout which loops around the whole magnetic structure, which is, in fact, the single winding solid iron core inductor, connected in series with ribbon. This is effectively depriving the ribbon of high frequency signal. The solution for this problem is, RAAL’s unique signal leads path, which doesn’t put the signal leads around the iron. The signal is fed to the ribbon through two symmetrical leads above the iron yoke, which effectively widens the bandwidth considerably. This layout also acts as a RF signal cancelling circuit, to stop the power amplifier being fed with radio frequency signals which might be picked up by ribbon acting as an antenna.

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.

FACE PLATE: One of the big existing problems is the use of thick front plates, so common in true ribbon designs, which are then bevelled to minimize their acoustical influence. On the other hand, bevelled front plate act as a wave guide somewhere in higher kHz range, ruining the linearity, so that has not solved the problem yet. RAAL’s unique front plates are very thin with no bevels, and our research brought us to the making of the zig-zag “acoustically invisible” front plate ribbon opening. The benefit is “non-wave guide”, seamless coupling or ribbon air loading to the open space, because of the “distributed parameter” edges of the opening. By that, we achieved the unmatched linearity in the upper kHz region and exceptionally “clean” impulse response.

FOAM DEFLECTOR PADS: Wide angle polar response is of great importance for the natural reproduction, therefore using the larger ribbon drivers bares a problem, since they are showing very intensive “beaming” of high frequencies, as they are line sources far bigger than the wavelengths of high frequencies in audible range. For model 140-15D, we found the solution for that problem in using the specially shaped foam pads in front of the ribbon. The dispersion pads are working as an acoustic lens, by slowing down the velocity of sound and thus shaping the sound wave front from cylindrical to spherical. The parasitic effect of partial sound absorption is inevitable, but acceptable. The pads are magnetic and they can slide on the front plate. By adjusting the distance between the pads, sliding them toward or apart each other, it is possible to shape the on-axis linearity vs. wide angle vertical polar response. In this way anyone can adjust the high frequency output by his-hers own liking. If the pads are

completely removed, 15 kHz on-axis response is increased in level of about 7 dB.

BACK CHAMBER: sub-critically damped compression chamber of ideal proportions provides the exceptional amplitude linearity and impulse response.

RIBBON REPLACEMENT KIT: ribbon replacement is made easy by our ribbon replacement kit, which is easily replaced by the user. This “kit” is in fact our SYMMLEAD® signal leading frame, holding the stretched ribbon, allowing it to snap into perfect position between the magnets.

This feature might be an obsolete one, because RAAL ribbons are destructible only by really extreme abuse or curiosity. In two years, we sent away only 3 replacement kits to customers who destroyed the ribbons by opening the drivers out of curiosity. Aside from that, our reliability record is 0% failure rate.

,  and , are registered trademarks of RAAL advanced loudspeakers d.o.o.