Ferrite Permanent Magnet Manufacturer China Rare Earth Magnet Limited

Ferrite Magnets for Speaker



1. Unit of Size: mm
2. Material: Table of Magnetic Performance for reference
3. Appearance: reference to GB9634-88或MMPA
4. Dimension Tolerance:
Outer diameter D: Tolerance will be controlled within ±2%.
Inner diameter d: Tolerance will be controlled within ±1.5%.
Height h: When outer diameter is shorter thanΦ100mm, the tolerance will be ±0.1mm. While outer diameter is longer than Φ100mm, the tolerance will be ±0.15mm.

Specification of Ferrite Ring Magnets :
Ø32*Ø18*(5-8); Ø35*Ø18*(6-8); Ø39*Ø22.5*(7-10); Ø40*Ø19(22)*(6-10); Ø45*Ø19(22)*(6-12);
Ø50*Ø22(24)*(6-12); Ø55*Ø24(26)*(6-12); Ø60*Ø32(24,30)*(8-16); Ø65*Ø32*(6-16);
Ø70*Ø32(45)*(8-18); Ø71.1*Ø32.5*15; Ø72*Ø32*(8-18); Ø75*Ø32(40)*(10-15);
Ø80*Ø32(40,60)*(10-18); Ø85*Ø45(32,44)*(8-20); Ø90*Ø45(32,35,50)*(10-18);
Ø100*Ø45(50,60)*(12-20); Ø110*Ø60(62)*(15-20); Ø119*Ø60(56)*(14-20); Ø116*Ø60(56,8)*(15-20);
Ø116*Ø60(56,8)*(15-20); Ø120*Ø60(45)*(12.5-20); Ø126*Ø60(65)*(12.5-20);
Ø128.3*Ø58.8*(15-20); Ø133.3*Ø59*(15-20); Ø135*Ø60*(15-20); Ø140*Ø75(62,65)*(12.5-20);
Ø145*Ø75(70)*(20-24); Ø156*Ø80(60)*(20-25); Ø165*Ø86.4*(15-25); Ø169*Ø85*(20-25);
Ø180*Ø95(80,85)*(20-25); Ø190*Ø89(90)*(20-25); Ø200*Ø86*(20-25); Ø211*Ø110(89)*(20-25);
Ø220*Ø110*(20-25); According customers’ requirement

China Rare Earth Magnet Limited manufactures over thousands kinds of ferrite permanent magnets, which are widely applied to loudspeakers, electro-motors, household appliance, mechanical apparatus, computers, aerospace and aviation instruments, measurement devices and electric clocks, mainly sold to Japan, USA, Australia, Italy, Hong Kong and Taiwan.

Three self-solved methods for problems of ferrite magnetic speakers in cars.
Speakers are the mostly used equipments in cars. It is inconvenient when the speakers are breakdown. Sometimes you honking the speakers, they sound like mosquito, very husky or even silent. Why will they be breakdown?

According to my experience, troubles with speakers are always defects of themselves. Especially those devices are installed in some incorrect position. When it rains, the speakers are easily to be soaked, which damages it. There are always three reasons for the troubles of speakers---themselves, the switch contact and horn harness. When your speakers have some problems, you can refer to the steps as follow.
1. Sometime the speakers are silent. When you press switch of permanent magnet speakers, it sometimes blares, or it sometimes doesn’t. This is often because the contact points inside are poor or the speakers have problems themselves.
2. The speakers sound husky, always because of bad contact of the plugs. Especially, contact around the steering wheels will be often wearing out due to frequent use.
3. The speakers are entirely silent. First, you should check whether the fuse is molten, disconnect the plugs and use multi-meter to examine whether the contact is power on when you honk the horn. If it is power off, you should check ferrite magnetic horn harness and relay. Or if it is power on, the problems are caused by the speakers themselves. You can adjust the conditioning nut of the horn and check whether it will sound. You should replace it if it remains silent.