Impedance Measurement - readings seem compressed

[wimvans]

Hello All,

I'm using the Impedance Measurement jig as described in the help files. Using the 60 ohm headphone output of my ART USB Dual Pre, the system measures loudspeaker and network impedances with clearly discernable resonances/peaks, however their values are way too low. For instance a JBL 16 ohm horn driver overall reads around the 8.2 ohm reference I've used. Peaks that should be around 32 ohms according to JBL read not more than 9.5 ohm. I'm calibrating the inputs carefully, am using an external power supply for the USB Dual Pre, so what could be wrong? Suggestions are really appreciated.

Thx, wim

 

[wimvans]

Here are examples of what I measure vs. factory measurement.

 

[EarlK]

Switch your two leads around and remeasure.

That's the most common mistake I see with ( the casual user ) .

 

[wimvans]

Casual user indeed. Time to make some clear markings.

Thank you very much EarlK!

 

[EarlK]

I'm glad that was the problem.