JPS58194499A - Speaker system - Google Patents

Abstract

PURPOSE:To increase the high band limiting frequency, by setting the attachment position of a ring-shaped structure to a diaphragm at the secondary node of the free oscillating axis symmetric mode of the diagram. CONSTITUTION:The diameter phi2 of the ring-shaped structure 6 which is attached to a diaphragm 1 is attached to the secondary node of the free oscillating axis symmetric mode of the diaphragm 1, and the other end of the diaphragm 1 is extended and attached to a voice coil bobbin 12 which drives the diameter phi1 touching the primary node. As a result, both the primary and secondary nodes of the free oscillating axis symmetrical mode are finally driven with the same phase. This can cancel both the primary and secondary resonance frequencies of the axis symmetrical mode of a flat plate. Thus the high band limiting frequency can be increased for a speaker.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speaker system that expands the bass reproduction frequency band with a small cabinet.
This is an attempt to expand the upper limit of the high frequency limit of this speaker system. Next, details of the present invention will be explained with reference to the drawings. The figure shows a cross-sectional view of the speaker system of the present invention. 1 is a flat diaphragm, 2 is an edge, 3 is a cabinet, 4 is a partition plate with a hole in the center provided in the cabinet, 5 is a bass reflex port, and 6 is a ring-shaped diaphragm attached to the diaphragm 1. Structure 7 is a ring-shaped structure attached to the field part, 8 is an edge-shaped sealed elastic structure that connects the structures 6 and 7, 9 is a damper that supports the voice coil bobbin, and lO is a Field part, II
12 is a voice coil bobbin that directly drives φ1 which corresponds to the first node of the free vibration mode of the diaphragm; 13 is a voice coil hoppin 1
This is the air vent hole made in 2.

By constructing the speaker system in this manner and appropriately selecting the shaded portion v2 in FIG. 1 and the volume (1) of the other internal cabinet portions, the low limit frequency can be expanded. Regarding this, a separate patent application (Japanese patent application 1986-
91854), so I will briefly explain it. The relationship between the area S of the diaphragm, the volume ■ of the cabinet, and the compliance CO constituted by both is, where the density of air is ρ and the speed of sound in the air is C, C0=-□ ・・・・・・・・・・・・・・・・・・ (1
) ρC2S2. Therefore, part of the diaphragm 1 and W of the cabinet 3
In addition to the first compliance consisting of fftV, the volume V
2 and composing the second compliance determined by (
J) As can be seen from the formula, as the area of a part of the diaphragm becomes smaller, the compliance increases on the order of the square of the diaphragm.
Furthermore, if the volume v2 is increased, the compliance increases proportionally and the low limit frequency can be expanded.

The present invention provides a speaker that can expand the upper limit frequency by attaching the diameter φ2 of the ring-shaped structure 6 attached to the diaphragm to the second-order node of the axially symmetrical mode of free vibration of the diaphragm. It is something. A number of methods have been proposed to cancel the second-order and higher-order axisymmetric resonance frequencies of flat speakers, but one of them is to drive the node of the second-order resonance frequency in phase with the first-order node. Conceivable.

In the present invention, by extending the other end of the ring-shaped structure attached to the diaphragm and attaching it to the voice coil bobbin, both the first node and the second node are driven in the same phase, so that the axis of the flat plate is Both the symmetric mode first-order resonance frequency and the second-order resonance frequency can be canceled, and the high frequency limit frequency of this speaker can be expanded.

As described above, the present invention can expand the low frequency reproduction frequency band even with a small cabinet, and furthermore, the high frequency reproduction t1Ml:I!
IF*tJ2;*-c @〜&i 51E n fc9
h'II: tv, is obtained.

[Brief explanation of drawings]

The figure is a sectional view of an example of the speaker system of the present invention applied as a bass-type speaker. 1--diaphragm, 2...enon, 3
・・・・・・Cabinet, 4 ・・・・・・・・・
Partition plate, 5 ... Bass reflex hoard, 6.7
・・・・・・・・・ Link-like structure, 8 ・・・・・・
...Elastic structure, 9...Dan...-1
10...... Field part, 11.13...
...Air vent hole, 12...Voice coil bobbin. Patent applicant: Matsushita Electric Industrial Co., Ltd.\monme tv1

Claims (1)

[Claims] An electrodynamic speaker comprising a flat diaphragm, an edge that supports the diaphragm, a voice coil that drives the diaphragm, a field section, and a magnetic air gap is installed in a cabinet other than a sealed type, and the flat diaphragm In addition to the loudspeaker system's appliance, which is determined by the volume of a part of the two-handed cabinet, a part of the flat diaphragm and an isolated space inside or outside the cabinet. In a speaker system in which the second compliance is configured to expand the bass reproduction frequency band, a ring-shaped structure is attached to the flat diaphragm to constitute the isolated space. What is claimed is: 1. A speaker system in which the structure is attached to a diaphragm so that its attachment position matches the second node of free axis-symmetric vibration of the diaphragm, and the other end is attached to a voice coil bobbin.