Loud-speaker cone - of impregnated paper on plastic with composite plastic corrugated rim

摘要

The speech coil is carried on the rear of the cone in the normal way and to obtain optimum acoustic response simply and cheaply, the rim is of plastic coated synthetic fibre felt, the coating being on one face and either in discrete points or over the whole face. Esp. it is applied as a complete foil cladding. Alternatively a foil may be sandwiched between two layers of felt and the whole be sealed together. The composite corrugated rim is then fixed to the cone by ironing on or by conventional heat and pressure methods.