Abstract: In a speaker system having plural speaker units, at least one of the plural speaker units has one resistor for level adjustment that is positioned between terminals of a speaker and a switch for switching connection circuits for connecting the resistor for level adjustment with the speaker. The resistor for level adjustment is connected with the speaker in series or parallel by the switch when performing the level adjustment. The speaker system can get two species of adjustment curves by using one resistor for level adjustment.

Abstract: A horn speaker system includes a dome-shaped diaphragm, a coil bobbin, a phase equalizer, and a magnetic circuit. The coil bobbin is integral with the dome-shaped diaphragm, and a voice coil is wound on the coil bobbin near a free end thereof. The magnetic circuit coacts with the voice coil for producing forces to actuate the dome-shaped diaphragm. The magnetic circuit includes a cylindrical magnet, a first annular yoke attracted to one end of the cylindrical magnet and having a central opening, a plate cooperating with the first yoke in defining a gap in which the coil bobbin is inserted, and a second yoke attracted to an opposite end of the magnet. The magnet, the first yoke, the first plate, and the second yoke jointly make up a closed magnetic circuit. The phase equalizer serves to keep sounds outputted from the dome-shaped diaphragm in phase. The phase equalizer is mounted on the first yoke and has a plurality of slits defined therein.

Abstract: An acoustic equalizer for use in a speaker unit including a central member in the shape of a generally spherical cone and a plurality of annular members arranged coaxially around the central member, the innermost one of which is partially linked through a linking portion to the central member with an annular vacant space between and each adjacent two of which are partially linked through another linking portion to each other with an annular vacant space between, wherein first ring-shaped end portions of the annular members and a first end portion of the central member surrounded with the first ring-shaped end portions of the annular members are provided to form in its entirety a spherical surface portion for facing a diaphragm member of a speaker unit and second ring-shaped end portions of the annular members opposite to the first ring-shaped end portions and a second end portion of the central member opposite to the first end portion and surrounded with the second ring-shaped end portions of the annular memb

Abstract: A diaphragm using a metal material applied with anodic oxide films, in which said metal material contains one of lead compounds, inorganic metal compounds and phosphor compounds at least to a portion in the micropores of the anodic oxide film.

Abstract: A diaphragm for a loudspeaker is described, which essentially consists of a polyolefin resin such as propylene homopolymer or copolymer with an ethylenically unsaturated copolymerizable monomer or a 4-methylheptene-1 resin and short fibers of potassium titanate. The titanate fibers have an average fiber length of 10 to 30 microns and an average diameter of 0.1 to 0.5 micron.