ESPRIT APM-6Monitor

Commentary

This is a speaker system that pursues the ideal point sound source by adopting the APM system and super-oval enclosure, seeking an attractive feature that the all-horn system does not have.
The unit is 502 cm by the APM (Accurate Pistonic Motion) method developed over five years with the aim of realizing various characteristics equivalent to the all-horn system.²And 16 cm²Planar speakers are used.

In the Woofer unit, a vibrating plate with a honeycomb core sandwiched between aluminum skins is driven at four points by four magnetic circuits and a voice coil. Since the points where the transition points of the divided vibration mode are concentrated are driven, the piston area can be widened and divided vibration within the service band is eliminated.
In addition, in order to prevent modulation distortion due to inductance change caused by the change in the amount of the pole piece in the voice coil depending on the state of the amplitude, a top pole is provided at the tip of the pole piece so that the inductance is constant regardless of the position of the voice coil.
In addition, slits are cut in the center pole and plate to suppress eddy currents and improve resolution in the mid-range.

The tweeter employs a vibrating plate with a honeycomb core sandwiched between carbon fiber sheet skins, and is driven by a powerful magnetic circuit and a large voice coil with four point drive points suppressed.
This unit adopts a structure in which the damper is incorporated into the magnetic circuit, and the span between the edge and the support of the damper is expanded to two to three times that of the conventional one, greatly reducing the occurrence of rolling.

In the Network Division, Sony has further developed its approach to faithful transmission, particularly by improving micro-level distortion and noise components.
All parts such as capacitors, coils, and resistors are fixed with SBMC to improve vibration resistance. In addition, oxygen-free copper is used not only for lead wires but also for resistor windings, and all coils are air-core to prevent magnetic distortion.
In addition, the network boards for the woofer and tweeter are placed as far apart as possible to prevent magnetic interference.
Each part of the network is attached to the enclosure via insulators to eliminate interference from mechanical vibration.

In order to prevent adverse effects due to diffraction effects, a superoval enclosure with an elliptical structure is adopted. A pattern of an ellipse called a superoval is calculated and the reflection of sound due to diffraction is effectively diffused.
The structure consists of alternating layers of natural wood and particle board using Sony-developed advanced processing technology.

Model Rating

Method	2-Way, 2-Speaker, Bass Reflex System, Bookshelf Type
Unit	For low band : 502 cm2Plane type For high band : 16 cm2Plane type
Playback frequency band	20 Hz to 20000 Hz
Output sound pressure level	88dB/W/m
Impedance	8 Ω
Maximum instantaneous input level	300W
Rated input level	100W
Crossover frequency	1200Hz
External dimensions	Width 545x Height 820x Depth 375 mm
Weight	48kg