DENON D-9
Price unknown (1 unit, around early 1970 s)
Commentary
A speaker system that has been developed over many years.
40RW09 which is 40 cm cone type woofer is mounted in the low range.
The diaphragm is composed of non-prescone paper mixed with collagen fibers and a roll edge molded with urethane foam. In order to improve linearity, this unit adopts a new method of increasing air compliance between the back surface of the damper and the voice coil gap. The voice coil adopts an edgewise wound voice coil.
The magnetic circuit has an external magnetic structure using 16 Arnaud magnets 40 φ x25mm. The top plate has a thickness of 15 mm, and the magnetic flux density of the bridge is obtained together with 80 φ center pole.
Aluminum die-cast frame is used for the frame.
A horn type unit using a driver unit HMD-9, an exponential horn and a newly developed acoustic lens HL-100C is mounted in the middle range.
The HMD-9 uses a special light alloy 45 φ diaphragm, and is a rear type driver unit with precision hand-made processing. The magnetic circuit uses eight Alnico magnets 25 φ x15mm and eight 25 φ x20mm.
The HL-100C consists of multiple layers of conical punching plates with different diameters at the opening of a horn-type speaker. This prevents the deterioration of directional frequency characteristics due to the influence of the vibration of the plate itself and the influence of reflection caused by the conventional thin flat plate acoustic lens.
Driver unit HTD-9 and horn H-2500L are mounted in the high range.
The HTD-9 is a unit equipped with a special light alloy diaphragm and a full-scale phase-equalizer. It can be freely used for 1400 hz cut-off horn.
The H-2500L is equipped with a diffuser with a hypervolic horn and open-celled foam sponge.
The enclosure uses a lumber core of 36 mm thick and carefully selected material for the entire surface except for the baffle.
It is also equipped with a variable acoustic resistance unit on the back to keep the playback limits and best transient characteristics.
The exterior has a walnut oil finish.
.jpg)
.jpg)
Model Rating
| Method | 3-way, 3-speaker, Acoustic Resistance Braking System, Floor Type |
| Units Used | For Low Band : 40 cm Cone Type (40RW01) For Middle Range : Horn Type (HMD-9 + HL-100C) For High Range : Horn Type (HTD-9 + H-2500L) |
| Frequency characteristic | Fo ~ 20 kHz |
| Directional characteristic at 60 ° | Fo ~ 15 kHz |
| Maximum allowable input | 100W (program source) |
| Impedance | 8 Ω |
| Average output sound pressure level | 97dB/W/m |
| Crossover frequency | 500 Hz, 8 kHz, 12dB/oct. |
| Cabinet Material | 36t, Lumber Core |
| External dimensions | Width 650x Height 880x Depth 530 mm |
| Weight | - |
| 40RW01 Specifications | |
| Type | 40 cm Cone Woofer |
| On-axis sound pressure level | 97dB/W/m |
| Allowable input | 35W(Nom) 100W(Max) |
| VC impedance | 8 Ω |
| Frequency band | 18 Hz to 20 kHz |
| Voice coil diameter | 8cm |
| Magnetic flux density | 11,000gauss |
| Total flux | 415,000maxwell |
| Weight | - |
| HMD-9 Specifications | |
| Type | Driver unit |
| Allowable input | 40W |
| Frequency band | 500 Hz to 15 kHz |
| On-axis sound pressure level | 105dB/W/m |
| VC impedance | 8 Ω |
| Magnetic flux density | 18,000gauss |
| Total flux | 100,000maxwell |
| Weight | - |
| Specifications of HL-100C | |
| Horn type | Exponential horn |
| Horn aperture | 100mm |
| Length | 216mm |
| Acoustic lens | Diameter 310 mm |
| Lens configuration | Punching Metal 23 Sheets |
| Specifications of HTD-9 | |
| Type | Driver unit |
| Allowable input | 35W |
| Frequency band | 2.5 kHz to 20 kHz |
| On-axis sound pressure level | 99dB/W/m |
| VC impedance | 16 Ω |
| Magnetic flux density | 17,000gauss |
| Total flux | 41,000maxwell |