Compare PCD to XSim do you get the same result?

[jhollander]

I must have a bad assumption.

I take a tweeter and woofer FRD and ZMA files at minimum phase and load them both into PCD and XSim for a simple 2 way. I export the combined response from PCD and use it as a curve in Xsim (Get File).

Everything matches perfectly

Same files, now I add an offset to the PCD woofer and export the combined response FRD from PCD. I can't get the XSim response to match by adjusting the offset of the woofer in XSim.

Seems like it's simple time delay when adjusting the offset of one driver.

What am I missing? Can anyone duplicate these results with any files you have?

[mobius]

Would your assumption happen to be that the offsets in PCD are the same as in XSim? Because that would be incorrect.

The offset in XSim is positive and because it lacks driver vertical reference data, the offset values should be larger in XSim too. The amount of difference will increase as the driver moves further away from the tweeter. Try changing XSim's delay variable to positive and start with the value you used in PCD. Then increase the value until your curves match. That should give you the correct offset value in XSim if I understand your dilemma correctly.

[jhollander]

Yes, I'm aware of the differences in the programs. The XSim offsets can be either positive or negative depending on the tweeter or reference measurement location.

My question is can you get them to match with any offset value (besides a zero value).

[Wolf]

When Mark and I were doing the Prazise models, we got very good correlation between the programs, as long as the offsets were entered into Xsim.

Later,
Wolf

[jhollander]

Ok I've found the problem. As usual operator error.

XSim uses the FRD files it has stored in a separate folder. If you update the FRD file, it will continue to use the old file until you reload the new file. If the file names are the same you can't tell. Sharing files across the cloud and multiple computers made this difficult to figure out.

[Psycoacoustics]

When Mark and I were doing the Prazise models, we got very good correlation between the programs, as long as the offsets were entered into Xsim.

Later,
Wolf

Hey Wolf, I may be confused but I was using WinPCD. Is that the same as Xsim? Mark

[DDF]

http://www.diyaudio.com/forums/multi-way/259865-xsim-free-crossover-designer-15.html#post4241792

[jhollander]

Thanks Dave.

[Wolf]

Hey Wolf, I may be confused but I was using WinPCD. Is that the same as Xsim? Mark

My bad- you are correct.
Sorry, John,
Wolf

[bwaslo]

Yup, XSim keeps its own private copies of all the data files, and saves them with the design file (that's so you can save the whole design with one file rather than having to pack all the needed files, too). Which can cause problems if you update the file. Just reload it from your source file in XSim and all should be happy.

A possible issue (not what was experienced but maybe something to consider) is that PCD might also apply attenuation per the different distances, while delay settings in XSim will only affect delay. Not likely to be an issue unless your mic is REALLY close or the delays dealt with are large.

[Jeff B.]

Yup, XSim keeps its own private copies of all the data files, and saves them with the design file (that's so you can save the whole design with one file rather than having to pack all the needed files, too). Which can cause problems if you update the file. Just reload it from your source file in XSim and all should be happy.

A possible issue (not what was experienced but maybe something to consider) is that PCD might also apply attenuation per the different distances, while delay settings in XSim will only affect delay. Not likely to be an issue unless your mic is REALLY close or the delays dealt with are large.

Hello Bill,
No, PCD doesn't attenuate based on distance, and the delays (offsets) are only for relative phase interactions. I will note that PCD will also save all loaded files and crossover settings as well. I never reload anything for any projects I am working on. I do really like Xsim though and i love the way it can handle any circuit I want to try.

Jeff

[jhollander]

Hoping some day that XSim gets a driver phase graph for the odd order x-os...

[bwaslo]

Hoping some day that XSim gets a driver phase graph for the odd order x-os...

Sorry, I don't understand.... You can get a phase graph of anything you can draw with any drivers you have files for (along with a "both" pair). What are you wanting?

[jhollander]

OMG, just found the phase button. Thanks