SL2 impedance scans and questions
Posted by: jfritzen on 30 May 2018
Hello,
perhaps someone can give me a hint:
As part of a small project, I've recently made impedance scans of my SL2s. Tweeter and mid/bass driver were measured separately, i.e. without passive crossover, and in-place.
So far the scans look sensible to me. However, there are some questions regarding the curves for the mid/bass driver (left and right driver, the impedance in the picture is shown on the right y-axis):
I think one can see that the drivers are relatively closely matched.
Two questions:
If I understand correctly the mid/bass driver in a ported speaker is supposed to show two large impedance peaks. However, there is only one large peak. Does this mean that the SL2 is not a ported speaker, despite the gap between the two enclosures, and should be seen as a sealed speaker? Or is my measurement incorrect?
And, just out of curiosity, there is a small peak at around 570Hz. Where does this come from? Certainly not from the port? The peak can be seen in both drivers, so the reason must be in the design and not a fault of the driver.
KR
Jochen