PURPOSE: To assemble easily a speaker with a uniform quanlity by positioning a diaphragm, an equalizer, and a front plate as the same reference to assemble the speaker and making it unnecessary to make the allowable error of each parts strict.

CONSTITUTION: A magnetic circuit of a vertical circular hole 22a is assembled in the center of a pole piece 22, and the outside wall fitted to the hole 22a and an equalizer part 21 are engaged with a jig 41, where a recessed notch mathced to a projecting face of the equalizer part 21, after a packing 25 is placed on the piece 22, and the jig 41 is fitted to the hole 22a until the lower face of the jig 41 is brought into contact with a front plate 2. A diaphragm 7 is arranged on the plate 2 through a spacer 24 coaxially to the equalizer part 21. A horn 23 provided with an inserting part fitted to the hole 22a and a flange part connected to the inserting part is fitted to the hole 22a from the side of a back plate 4 until the flange part is brought into contact with the plate 4.