| 摘要 |
In loudspeakers (figure 1) with so-called "symmetric drive" (SD) there is mounted about the central magnet pole piece (6) a copper cylinder (22), and a corresponding cylinder (24) is mounted in front of this pole piece, projecting outwardly as far as corresponding to maximum displacement of the voice coil (16). According to the invention (figure 2) the same or even a better compensation result is achievable with the use of a considerably reduced amount of copper, viz. by means of a short copper ring (22B, 24B) at each side of the air gap (14) and a somewhat longer, yet still relatively short copper ring (22A) about the root portion of the pole piece (6). <IMAGE> |
