Infinity Kappa 9 crossover schematic

[FrankieS]

Hi, dear all,

beginners question (sorry):

I simulated with TINA (SPICE) software the woofer part of the crossover of the Infinity Kappa 9 (see attached).
When I do a sine wave sweep with TINA this crossover part appears to be a high pass.
However doing the same for Kappa 8 a bandpass is evident.

Is there a mistake in the company Kappa 9 schematic, as there seems to be lacking a terminal
electrolytic cap in the crossover (wheras Kappa 8 has such an electrolytic cap) ?

Did anybody do simulations/optimizations for the Kappa 9 and Kappa 8 crossovers ?

thank You very kindly,
FrankieS

 

[FrankieS]

Maybe my initial simulation was not correct, because I did not add a load ?

 

[RVT1K]

I don't have any experience with SPICE but I would have to think that in order to get correct results, the entire circuit needs to be included in the model.

 

[RTally]

Maybe my initial simulation was not correct, because I did not add a load ?

The load is more complex than a simple resistance. At the very least, you need to use the VC resistance (not the nominal impedance) and the inductance of the winding. But using only those parameters ignores the dynamic nature of the moving VC. One solution is to use the driver inductance measured at 1kHz.

See, for example, https://audiokarma.org/forums/index.php?threads/how-to-find-le.354117/

 

[FrankieS]

thank You kindly RVT1K and RTally,
much appreciated.
I'm really at the beginning of all this. learning these things are very interesting. but then maybe simulations do not serve too much
for real world optimizing, because the systems are by default complex and the parameters not all given.

anyway interesting.
bye,
FrankieS

 

[RVT1K]

thank You kindly RVT1K and RTally,
much appreciated.
I'm really at the beginning of all this. learning these things are very interesting. but then maybe simulations do not serve too much
for real world optimizing, because the systems are by default complex and the parameters not all given.

anyway interesting.
bye,
FrankieS

There is free software - XSim - that allows you to model crossover response. But to get the best results out of it, you need to import specific files for each driver. I know one file is the impedance of the driver over the audio range -.zma- and I think the second is for acoustic output over the audio range -.frd-. Unfortunately those files are probably unavailable for your application.
I played around with it to keep me busy and had a lot of fun. Parts Express has the files for some of the Dayton Audio drivers they sell.