User Manual

A White Paper Of The Installation Series Loudspeakers
The magnetic circuit uses a large ferrite magnet
for enhancing the magnetic density, resulting
clear and crisp sound.
- Enclosure
After the listening tests, we decided to use 11-
ply Finnish Birch for the enclosure material.
The tuning frequency is set to the point where
the sound pressure from the port affects the
low-frequency response most effectively.
We made prototype in which the tuning
frequency point was calculated by computer
simulation and gave the listening tests
repeatedly for checking the matching between
the enclosure and woofer, then made change
for improvement.
As for the enclosure shape, to keep the clear
sound, we set the side panel and baffle to the
same height. This eliminates sound reflection
by the side panel, which may make the sound
unclear.
We reinforce the inside by bracing, considering
the strength and resonance. In result, we ensure
the clear tone quality with no speaker box noise.
25-mm glass wool is used inside the enclosure
as the sound-absorption material, resulting the
well-balanced low-frequency sound that is tight
but sustained.
To get the higher sound penetration, 63 % of
the metal grille is open.
- Network
To prevent the sound deterioration by inserting
the network, the network is very simple.
For the low-frequency network of the 15- and
12-inch models, a coil binding 15-gauge copper
wire to the large silicon steel plate core and a
large film capacitor with small Tan θ, ensuring
the high resolution sound even at high power
input.
To get the same phase response and amplitude
response as those at the bi-amp operation, we
made computer simulation and actual
measurement repeatedly until we completed the
network design.
As a whole, we could accomplish both "In
Phase Concept" and "Family Sound Concept".
We could minimize the phase change over the
whole range and obtain the gentle descending
phase characteristics with no sudden phase
change, as well as obtain the smooth amplitude
characteristics.
5. Phase characteristics of the
"Installation" series
The following graphs show the phase
characteristics of the Installation" series and the
competition model.
From these graphs, you can see that the phase
characteristics of the "Installation" series are
almost the same, regardless of directivity, drive
mode and model.
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