Error calculating Thiele-small parameters - resonances too close

[DeepSOIC]

Hi! Thanks for awesome software, but today I have a problem.

I'm trying to measure TS parameters of a small driver.

However, I get an error "The resonant frequencies of the selected measurements are too close to generate reliable results."

I don't know how to solve it. I've measured countless other speakers, mostly without problems (sometimes I did hit a glitch caused by false data at 22 kHz due to brickwall filter, that could be solved by reducing the frequency range a bit).

Rdc = (ohm)
3.62
eff area = (cm2)
5.30
dm = (g)
0.504

REW 5.20 beta 6

 

[John Mulcahy]

Seeing that the impedance all looks to be sitting higher than it should by the value of your sense resistor I'd say the channels are swapped. Try telling REW the input is on R rather than L.

 

[DeepSOIC]

the channels are swapped.

Sorry about the noise, that was exactly the problem! I didn't even know it's changeable. Thanks!

 

[John Mulcahy]

No problem. Swapping the input channels also shifts the phase by about 180 degrees, I've added a check in the code for the phase at resonance being close to 180 degrees instead of close to 0 degrees to warn that the channels may be swapped.

 

[DeepSOIC]

I've added a check ... to warn that the channels may be swapped.

Wow, thanks!!