Backloaded horn
speaker has a full-range speaker driver. A
full-range speaker driver is the ideal because it moves a
lightweight diaphragm with strong magnetic circuit. For
example, the drivers Mr.Tetsuo
Nagaoka used for his
designed backloaded horn speakers were SPL 96.5dB Qo 0.26;
FE-206ƒ°, SPL 98dB Qo 0.16; FE-208S and SPL 99dB Qo 0.15;
FE-208SS. However it doesn't play a practical bass if you
mount it on the general enclosures, like closed-box and
bass-reflex.
For 2-way speaker, it has a woofer
and a tweeter. The woofer has a heavy diaphragm with
weak magnetic circuit for easier to play the bass. So, its
SPL is low. Therefore, the tweeter has a
resistor/attenuator to suit the SPL of
the woofer; it reduces the SPL as speaker system. (see
diagram below)
Crossover
Network
6dB/oct
12dB/oct high-pass impedance correction
circuit
However
you are able to derive a satisfactory bass through
the long horn from back side sound of the full-range
speaker driver by back loaded horn
enclosure.
And a full-range speaker driver
hasn't crossover network unlike 2-way or 3-way speakers; it
hasn't any circuit elements such as capacitors, coils
and resistors/attenuators. (see diagram above) So,
it expresses the sound source more real and the
sound quality is completely unaffected by the network and
the resistors/attenuators.
Consequently, the
backloaded horn enclosure is able to derive its
full ability from the ideal speaker
driver. Therefore, backloaded horn enclosure provides
big speakers-like bass and volume level even small
speakers.
The design points for backloaded
horn enclosure are the cubic capacity of an air chamber,
the cross-sectional area of its throat, the horn flare
rate, the horn length and the horn-opening area. Fold up
the horn and
crate it.
principle of backloaded horn
One of the
things it is highly-efficient system. In other
words, it has a high output sound pressure level; the
backloaded horn system is an energy-efficient design. So it
allows the driving by low-power amplifier, too. Low-power
amplifier is good from the point of view of sensitive
sound.
It plays the fine sounds because
the driver diaphragm can move easily by backward
opening of the speaker driver, like open back type cabinet.
So, it plays the realistic sound with overwhelming high
quality if its sound source is good, but that's not how it
works if its sound source is poor. Therefore, you may
have trouble finding a good sound source.
You
might hate the backloaded horn sound, but everyone will
be surprised at the difference
between the sound of backloaded
horn and others. Furthermore, you will never
believe the magnificent bass, the powerful sound and the
instantaneous force for small-diameter
driver.
Reasonably-priced backloaded horn
speakers are not many because of internal complicated
structure. So, many audio nuts made that by
oneself.
However, Hasehiro Audio achieved a
low price. Moreover, they succeeded to eliminate
right-angled bend from horn like below
MM-161T.
Hasehiro Audio MM-161T
Designed by Tetsuo Nagaoka D-58
(in the making)
Conventional backloaded horn is a
pseudo system such as conical horn or combination of
some straight ducts, like above Nagaoka D-58. So, the
systems don't have an intrinsic backloaded
effects.
But Hasehiro backloaded system is
exponential curved horn. Hasehiro backloaded horn that
you've known up until now has changed completely in new
backloaded horn speakers. i.e.,Elimination of a hollow-gray sound by
acoustic reflection at the folded
places of the horn (standing
wave). Therefore, Hasehiro backloaded horn system is not
an indispensable high SPL speaker
drivers.
Dense MDF (Medium-Density Fiberboards) is extremely
good at listening characteristics because of low
sympathetic
vibration.
You can
get yearning exponential backloaded horn speakers at
last. Let's be intoxicated by a beautiful curve makes the
ultimate back loaded horn sound.
Backloaded
horn system brings out undertone through the long horn
from back side sound of the speaker driver. As a result,
backloaded horn system provides big speakers-like undertone
and volume level even small speakers. Furthermore, Hasehiro
backloaded horn is calculation-based design and
exponential curve. That's exactly the wind
instruments. Exponential curved horn
doesn't form strange peak value. That means it is
like open back type cabinet, but it guides undertone to the
front through the horn. So, the efficiency is high and it
has a good balance among ranges. That is one
of Hasehiro backloaded horn's
advantages.
And
Hasehiro backloaded horn system doesn't get back
pressure beyond a certain level. That
means it keeps the balance better relatively under any
volume level because it doesn't have harmful effects on the
cone motion. That is one of Hasehiro backloaded horn's
advantages, too.
If you learn the
sound of the exponential curved backloaded horn speaker
more, you had better get into the "Fresh Voices" next.
Tetsuo
Nagaoka published the designs as many as 600 kinds of his
own speakers in his lifetime. Particularly, he focused on
the backloaded horn speaker design because the audio
industry had the conventional wisdom that "the backloaded
horn speaker has a bad sound." So, he wanted to prove the
characteristics and the advantages of the backloaded horn
speaker.
In 1980 Tetsuo Nagaoka published
the matrix speaker: MX-1.
In 1986 Tetsuo
Nagaoka published the point sound source systemed
backloaded horn speaker: SWAN.
In 1992 Tetsuo
Nagaoka published the point sound source systemed
backloaded horn speaker:
SUPER-SWAN.
Basic Knowledge: -Measured data from 253
drivers -Q&A for DIY speakers -Full list
of original speakers by T.Nagaoka (Japanese
book)
Design Drawings #1: -Back loaded
horns / Matrixes -Nondirectional systems /
AV systems -Separate systems / Ensemble
systems -Super woofers (Japanese
book)
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