Audio Database

SB-501
Commentary

This dome-shaped 3-way speaker system was developed by combining the advances in acoustic technology of Technics.

A 30 cm cone type woofer is installed in the low range.
The cone paper used in the diaphragm prevents split resonance by reducing the beating degree of the material (an indication of the amount of air leakage) and increasing internal loss. In addition, the surface is coated with a special resin to increase density, so that only the surface is hard and the back is light.
The magnetic circuit consists of a 4-layer voice coil made of light aluminum wire and a large ferrite magnet with a diameter of 145 φ. By increasing the force coefficient, a design with a margin for setting fo and Qo has been realized to improve efficiency and strain characteristics.
Urethane edge is used for the edge.

The mid-range has a 15 cm dome mid-range.
The diaphragm has a roll-shaped free edge and a back cavity, which reduces fo to 230 Hz and improves low-frequency playback.
In addition, by using the double damper system, the rolling phenomenon that tends to occur at the time of large input is suppressed.

A 10-cm dome type tweeter is installed in the high range.
A titanium diaphragm is used for the diaphragm, and by using newly developed processing technology, an ultra-thin 20 μ m thick titanium foil is realized, and by using the titanium diaphragm, a 30% reduction in weight compared to the conventional aluminum system has been achieved.
Titanium foil is also used in the edge part, and it succeeded in lowering fo to a low frequency of 1.7 khz.
Edge resonance, which tends to occur in low frequencies, is suppressed by a special damping agent.

Each has its own level control for the middle and high ranges.

The enclosure is sealed and the exterior is finished with rust-antique oil.

Model Rating
Method 3-Way, 3-Speaker, Airtight Type, Bookshelf Type
Units Used For low band : 30 cm cone type
For Middle Area : 15 cm (Unit Diameter) Dome Type
For High Range : 10 cm (Unit Diameter) Dome Type
Playback frequency band 20 Hz to 30000 Hz
Impedance 8 Ω
Output sound pressure level 92dB/W/m
Max Input 45W
Crossover frequency 600 Hz, 4000 Hz (12dB/oct.)
Level control For Middle Range : + 2 ~ 0 ~ -6dB
For High Range : + 2 ~ 0 ~ -6dB
External dimensions Width 380x Height 660x Depth 324 mm
Weight 19kg