Audio Database

Commentary

This is a 3-way speaker system that pursues what power linearity should be for music.
Output sound pressure deviation of ± 2 dB is achieved over the frequency range from 65 Hz to 16 kHz.

A 33 cm cone woofer is installed in the low range.
This unit improves the power linearity by equalizing the magnetic flux distribution in the magnetic circuit. The magnetic circuit is equipped with a needle type yoke and an Alnico cast magnet. The needle type yoke is more uniform in the magnetic flux distribution because the opposed area of the gap between the plate and the pole piece is equal compared with the conventional yoke. The magnetic force of the magnet can be used effectively to improve the power linearity.
In addition, in order to prevent the linearity deterioration caused by the air in the air chamber surrounded by the damper, frame and top plate, a ventilation hole is provided between the damper and frame to flatten the playback response and suppress the third harmonic wave.
The CF cone of the diaphragm is coated with titanium oxide to improve the reproduction response. This diaphragm is supported by an S-shaped, asymmetric cross-section, ester urethane foam edge with low anti-resonance.

Equipped with 12 cm cone type skoker in the middle area.
In this unit, the pole piece of the magnetic circuit is cut in a T-shape to obtain a uniform magnetic field, and an air vent is provided between the damper, frame and top plate to suppress the 3rd harmonic wave.
The cone paper is designed based on the results of optical measurement of the amplitude at the time of large input. It uses an expanded curved cone developed based on the conclusion that it is preferable to limit the movable range of the edge to a value of ± 1.5 mm.

A horn type tweeter using a ring diaphragm is mounted in the high frequency range.
In general horn type tweeters, a dome type diaphragm is used. However, in the dome type, the distance between the driving surface of the voice coil and the top of the dome is long and the strength is weak. Therefore, the piston does not move at high frequencies, and many peaks and dips are generated in frequency characteristics, which leads to deterioration of linearity and adversely affects the transient response.
The LS 505 tweeter diaphragm uses a V-shaped ring diaphragm molded with super duralumin. By shortening the distance from the driving surface to the edge, the frequency at which split vibration occurs becomes higher, high-frequency resonance is less likely to occur, and the transition from the piston vibration band to the split vibration band becomes smooth and flat. The V-shaped diaphragm further improves linearity by providing small V-shaped edges on the inner and outer periphery.
The magnetic circuit uses an 80 φ 20 mm ferrite magnet with a magnetic flux density of 15,000 gauss. The air chamber between the pole piece and magnet is filled with micron glass wool to prevent sound reflection and improve damping characteristics.

Litz wire step-down attenuator is used for the level control part.
A continuously variable attenuator was used for the level control of conventional speaker systems. However, this method has a problem in that sound quality deteriorates at the position of the volume level. When the speaker is driven by the input from the amplifier, a back electromotive force is generated in the voice coil and returned to the amplifier, resulting in a state in which damping is heard well. However, when the continuously variable attenuator is reduced, the DC resistance between the amplifier and the speaker increases, reducing the damping factor and causing sound quality deterioration.
The LS 505 uses a step-down attenuator using Litz wire to suppress the deterioration of the damping factor due to the step position. This attenuator has the advantage that it does not produce skin effect even at high frequencies, extends the high-frequency range, and does not affect the frequency characteristics of the attenuator by the impedance characteristics in the middle and high-frequency range.

In the LS 505, the phase distortion near the crossover between the tweeter and the skoker is also taken into consideration, and the sound source of the skoker and the tweeter is designed to be on the same plane. This prevents deterioration of the playback response due to phase distortion near the crossover.

High-density homogen chipboard is used for the side and top and bottom plates of the enclosure, and Yonematsu lumber core with excellent strength and damping characteristics is used for the baffle plate and back plate. The enclosure with excellent damping characteristics is realized by considering the arrangement of reinforcing materials.
In addition, a standing wave canceler (SWC) is installed in the bass reflex duct to suppress standing waves that degrade mid-range characteristics and obscure mid-range sound quality.

Model Rating
Method 3-Way, 3-Speaker, Bass reflex system, Bookshelf Type
Unit For Low Band : 33 cm Cone Type (LC-0062)
For Middle Range : 12 cm Cone Type (ML-0057)
For High Range : Horn Type (HH-0054)
Frequency characteristic 32 Hz to 20 kHz
Output sound pressure deviation 65 Hz ~ 16 kHz ± 2 dB (Close to Rear Wall, Base 45 cm)
Distortion factor 0.3% or Less (1 kHz)
Second harmonic : 64 Hz to 7 kHz
Third harmonic : 64 Hz to 20 kHz
Max Input 100W
Rated input 65W
Impedance 8 Ω
Output sound pressure level 93dB/W/m
Crossover frequency 1.3 kHz, 6.5 kHz
Level control Mid-range : -2, 0, + 2 dB (3 steps)
High frequency : -3, 0, + 3 dB (3 steps)
External dimensions Width 376x Height 676x Depth 325 mm
Weight 26kg
Sold Separately Speaker Stand SR-2000S (2 pcs 1 set, ¥ 12,000)
Unit Characteristics
Model number LC-0062 ML-0057 HH-0054
Type 33 cm cone type 12 cm cone mold Ring diaphragm horn type
Playback band Fo ~ 2.7 kHz 400 Hz to 10 kHz 3 kHz to 20 kHz
Output sound pressure level 93dB/W/m 95dB/W/m 104dB/W/m
Impedance 8 Ω 8 Ω 8 Ω
Magnetic flux density 10,000gauss 12,000gauss 15,000gauss
Total flux 145,000maxwell 44,000maxwell 28,400maxwell