Bohlender Graebener NEO-8 Brochure
Radia
NEO-8
Professional
Speakers
The NEO-8 and NEO-8 PDR
High Performance Wideband
Planar Magnetic Transducers
The NEO-8 and NEO-8 PDR are planar-magnetic
(ribbon) transducers that use an innovative hightech diaphragm material called Kaladex from
Dupont. This material, combined with a new
proprietary technology for etching the
aluminum/Kaladex laminate, makes it possible to
overcome the usual limitations of previous
generation planar-magnetic designs. Traditionally
most planar drivers were built using a Mylar
diaphragm but Kaladex has a much higher
thermal limit, lower mass, better durability and
mechanical stability. As a result, the NEO-8 and
NEO-8 PDR transducers have higher sensitivity
and power handling as well as excellent sound
quality. The careful design and unique assembly
technology employed by these units allow for
more extended high frequency output, less
distortion and higher dynamic range than with few
other planar drivers of similar size.
The NEO-8/ NEO-8 PDR have a push-pull
symmetrical magnet system that has been
designed with the help of Finite Element Analysis
software to achieve optimum efficiency/cost
performance. It uses the newest grades of
neodymium – the “super” magnet material with the
highest magnetic energy. The extremely light
Kaladex diaphragm with an etched planar
aluminum conductor is suspended in a magnetic
field and is uniformly driven by the
electromagnetic force providing accurate and
immediate reproduction of the input signal.
NEO-8 / NEO-8 PDR do not have heavy voice
coils, spiders, glue joints, paper cones and
surrounds, there is virtually nothing between the
electrical signal and the sound - just an almost
weightless diaphragm. Hence these planar
NEO-8 PDR
transducers do not have cone break-up resonance
with associated distortion, phase incoherency or
signal smearing that is common for conventional
drivers. This allows Neo drivers delivering clean,
airy, transparent sound that is inherently natural
and musically pleasing.
The purely resistive impedance of the NEO-8 /
NEO-8 PDR makes an easy load for a power
amplifier and greatly facilitates crossover design.
The magnet system is completely shielded for
safe implementation in multimedia and AV
systems. The NEO-8 / NEO-8 PDR are very
versatile transducers and their applications are
limited only by the designer’s imagination.
Fig.1 shows a family of curves representing (from
top to bottom) on-axis, 30° off-axis, and 60° off-
axis response of the NEO-8 measured as a dipole
(without baffle or rear enclosure) at 1 meter for a
2.83V input. It is evident that the superior
dispersion uniformity up to 7 kHz will allow the
NEO-8 to deliver smooth and balanced sound in a
real listening environment. It is necessary to
stress that using the NEO-8 as a dipole (without
any rear enclosure) may require some signal
equalization at lower frequencies, since a dipole
exhibits a natural roll-off. In some applications
where flat on-axis response is desirable, the use
of a correction network at 12 kHz is
recommended; in others correction may not be
necessary, since spatial averaging will provide
smoother power response without the12kHz peak
reduction. Line array systems may not need the
notch filter due to specifics of acoustical coupling
in these systems. The notch filter schematic is
given at the end of this document.
Fig.1 NEO-8 SPL on-axis, 30
°°°°
°°°°
Fig. 2 NEO-8 SPL under different loading conditions
off-axis, 60
of-axis
Fig.2 Neo 8 SPL under different loading conditions
Fig 2. shows the effect of small baffle loading. This condition is close to a typical system or situation when the
transducer is a part of matrix panel combining multiple drivers. Top curve – the NEO-8 in the center of 9”x 9”
baffle, middle curve - the NEO-8 with 9”x 4.5” baffle from one side, bottom curve – the NEO-8 without a
baffle. It is worthwhile to note that a carefully designed rear enclosure provides additional equalization at the
low end of the reproduced frequency spectrum.
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