Modulation Distortion in Loudspeakers
When comparing a loudspeaker with direct radiator bass system to one with horn loaded bass, the subjective judgment is that the one with the horn loaded bass is -cleaner.- The difference in listening quality appears to be due to modulation distortion. The mathematical analysis of modulation distortion is reviewed and spectrum analyzer measurements are described which have been correlated with listening tests. The spectrum analyses corroborate the mathematical analysis and the listening tests offer a subjective evaluation. It is concluded that frequency modulation in loudspeakers accounts in large measure for the masking of -inner voices.- Reduction of diaphragm excursions at low frequencies reduces FM distortion. Horn loading, properly applied, offers greatest reduction, while simultaneously improving bass power output capability.
Click to purchase paper or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $20 for non-members, $5 for AES members and is free for E-Library subscribers.