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Discussion Starter · #1 ·
Hi REW Forum :)

i would like to measure the TSP of a unknow driver. So i build the electronic circuit from here: http://www.roomeqwizard.com/wizardhelpv5/help_en-GB/html/impedancemeasurement.html. And i used this two impedance measurements:

1. Without any added mass
2. With 17g added mass

I entered the values in TSP Tool window like this.

But i get the error:

"The resonant frequencies of the measurements are too close to generate results."

Where is the problem?

I also don't understand why i get over 100 ohm although i entered 100 Ohm Rsense
 

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It sounds like you need to add more mass than 17g to significantly change Fs.
 

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Discussion Starter · #3 ·
But why do i get more then 100 Ohm on my measurement? Also the phase does not look right...

If i use 25.5 Gramms i get this response but i still get the same error if i want to calculate the tsp. I am also wondering why i get a second impedance maximum on the added mass measurement at ~130Hz...
 

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Impedance that is above the ref value usually indicates that the connections are the wrong way around (left and right swapped). The second peak is pretty odd, assuming the driver is not in an enclosure.
 

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Discussion Starter · #5 ·
Hi John,

thanks for your answer. Now it looks correct to me. But the second impedance maximum is still appearing and therefore i get an error at tsp calculation although it looks much better now...

I did both measurements in free air without any volume.

How do i get the Vas TSP-Parameter?
 

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REW can't accommodate that double peak (I don't know what could). It is a fairly small driver, perhaps the mass is too large and contributing to the appearance of the second peak? Worth trying a smaller mass.
 

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Discussion Starter · #7 ·
Hi John,

the TSP calculation works with a very low mass (around 3 - 5g). Great tool you have built there by the way. I am really looking forward to build my next speaker with this driver in a small Transmission line :)
 
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