Impedance measurement is often the sole electrical measurement in a battery of QC tests on loudspeakers and headphones. Two test methods are commonly used—single channel and dual channel. Dual Channel measurement offers greater accuracy as both the voltage across the speaker (or headphone) and the reference resistor are measured to calculate the impedance. Single Channel measurement methods are more commonly used on the production line because it only requires one channel of a stereo soundcard, which leaves the other free for simultaneous acoustic tests. They are less accurate, however, due to the test methods making assumptions of constant voltage or constant current. In this paper we discuss a novel electrical circuit that offers similar impedance measurement accuracy compared to complex dual channel measurement methods but using just one channel. This is expected to become popular for high throughput production line measurements where only one channel is available as the second channel of the typical soundcard is being used for simultaneous acoustic tests.
Temme, Steve; Scott, Tony
Affiliations: Listen, Inc., Boston, MA, USA; Octave Labs, LLC, Eastchester, NY, USA(See document for exact affiliation information.)
AES Convention: 135 (October 2013) Paper Number: 8991
Publication Date: October 16, 2013
No AES members have commented on this paper yet.
If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.