When the motor of a classical electrodynamic loudspeaker has been replaced by a so-called magnet-only motor, current distortion caused by magnetic circuits is significantly reduced. All of the nonlinear soft-iron pieces are removed, and the magnetic field is created by a combination of permanent magnets. Two loudspeakers are compared in the study: the first sample is a mass-produced 6.5-inch loudspeaker. The second sample is built replacing the magnetic circuit of the first loudspeaker by the magnet-only structure. Thus, the moving parts, including the voice-coil, diaphragm, and suspensions are kept identical for both samples, leading to a comparison based only on their motors. The measurements on the original loudspeaker have shown a significant variation of apparent resistance and inductance of the voice-coil with current, displacement, and frequency. Conversely, the measurements on the magnet-only loudspeaker have shown almost no variation whatever the frequency, current level, or position of the voice-coil.
Merit, Benoit; Novak, Antonin
Affiliations: Orkidia Audio, 64310 Ascain, France; Laboratoire d’Acoustique de l’Université du Maine, UMR CNRS, Le Mans, France(See document for exact affiliation information.)
JAES Volume 63 Issue 6 pp. 463-474; June 2015
Publication Date: June 30, 2015
No AES members have commented on this report yet.
If you are not yet an AES member and have something important to say about this report then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.