Unisef - speakers in audio player, China or Japan?

Эта статья на русском языке

Cassette players once enjoyed huge success, then the compact cassettes were driven CD-laser discs, which had their own miniature players ... by that time there are enough audio players, both domestic and international. Today I will introduce you new antique piece of recent history - tiny speakers to a cassette player.

Column, as the player itself are named UNISEF - had the Japanese company in Tokyo, available consumer electronics ... emblazoned on the speaker label "Made in Japan", but whether he did in Japan or Chinese forgery ... who knows? The Japanese company is sometimes produced pretty shabby gizmos, so that they can be expected anything ...

Logo Unisef column

So, these speakers are made of plastic red, stable plastic, 2.5 mm thick. Speaker dimensions: height 93 mm, width 77 mm, thickness (depth) of 38 mm. The body consists of two parts strapped together by two screws. The front panel is covered with steel protective mesh on the back is an opening for the connecting wires - no connectors, wire goes directly to the speaker. Also on the back side is not clear on the face of a cylindrical cavity. Disassemble the column and immediately becomes clear that this is a strange thing as clamp the speaker to the front - no other attachments speaker has. The back wall inside glued layer of foam - pretty dubious dampening solution, the more columns are not nearly tight ...

Connecting wire inside tied knot to prevent breakage of the speaker for the unwary user.

Dynamic head. In these columns using a regular cheap speaker unknown manufacturer. Circular, with a diameter at the outer edge of the basket 66 mm (total height / depth of the speaker 22 mm). Cart - stamping of steel 0.5 mm thick. No mounting "ears" on the basket no speaker should either stick or cling (as in our case). Diffuser and suspension at the same time made of paper pulp, the diameter of the cone, including the active part of the suspension - 58 mm. At the edge of the suspension glued cardboard collar. In the center of the cone paper dust cap in a light color. Lead wires are thin (0.35 mm), woven. Pad is marked with "+" and "-", solder contacts themselves. Centering washer common corrugated of coated fabrics.

A magnet on the speaker is not shielded, diameter 30 mm, thickness 5 mm. The magnet is strong enough ... Steel flange on the end marked Voice Coil Resistance - 4 Ohm, also has the inscription "Japan" - but the Japanese if he is unknown. End flange and core are made of a single piece of steel by forging. Flange thickness of 2.5 mm. Core diameter 13 mm, height 7.5 mm. On the other side of the magnet is also a steel flange, also made of steel and 2.5 mm inner bore of 15 mm diameter, but it forms an air gap, it is used to mount the magnetic system to the basket of the speaker. The magnetic system is very firmly attached to the basket and I was easy to separate them (or not destroying anything). Any traces of glue or epoxy I discovered. But in a small basket, "skirt", and pressed into her basket to the inner flange, namely it creates an air gap with Kern. Diameter of 14 mm. Consequently, the width of the air gap - half a millimeter.

I must say the quality of the magnet: These steel flanges are glued to the magnet and glue a very "angry." To detach the magnet from the plate end flange with Kern I had hammering very hard and it is just barely possible. Magnet with was unharmed and not even crumble at the edges ...

Now for the coil. Reel of strong impregnated paper, height 19 mm, with an inner diameter of 13.5 mm, the outside diameter of the winding wire with 13.75 mm. The coil wire is wound in two layers: the inner coil 23 and 21 round outdoor, copper wire 0.13 mm.

Despite the external cheap form, this speaker is made very carefully. It is found during disassembly (I used the "destructive" method). All glued together efficiently and accurately. Everything is made of good materials.

Evaluate the sound quality of my full, unfortunately, not possible - a single speaker has been damaged by the owners ... and judging by the sound of a speaker - not a fountain ... that way at the level of the Soviet subscriber speakers.

Centering washer

Diffuser, centering washer and coil taken out of the speaker box

Kern centering washer cut ...

Michael Dmitrienko, Alma-Ata, 2012