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How to create your own frequency and impedance files for X-Sim


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X-Sim is a free, easy-to-use, and effective software tool for modeling passive crossovers. I am not claiming mastery of the software but I learned how to turn an image of a frequency response or impedance graph into the required .frd and .zma file, and I wanted to share.

 

I found another program, Vituixcad, which is another free software tool, but this one, from what I can tell, is a complete speaker design software suite. All I know about it so far is how to use the "SPL trace" function to create the files for X-Sim. I'm sure this program does what X-Sim does but I haven't delved into it. 

 

X-Sim is great for building new passive crossovers, and almost indispensable for modifying/upgrading existing crossover designs.

 

https://kimmosaunisto.net/Software/Software.html

http://libinst.com/Xsim/XSimSetup.exe

 

If you have the frequency response and impedance graphs, along with some of the driver's specs, you can do this.

 

Here are the FR and Z graphs for the FaitalPro H-111 high frequency driver:

1386066153_Annotation2020-03-08134947.thumb.jpg.9d99d95a57b67239494d35d11308c619.jpg

 

 

Open up Vituixcad, open up the "SPL Trace" tool, and import the FR graph image. Adjust the high and low amplitude limits of the graph by moving the horizontal green and blue lines to the highest and lowest spots on the curve. Type the db level of those limits on the left side of the window in the fields next to the green and blue squares. Use the vertical yellow and purple lines on either side of the graph to establish the frequency limits and type in the graph's values in the fields next to the yellow and purple squares. Make sure the "Z Axis type" is set to linear.

213850649_Annotation2020-03-08134947z.thumb.jpg.211495ab07a4ce299633cd893fb94c44.jpg

 

On the left side above the blue square, you will click the "Trace SPL" button then start clicking along the curve itself. The curve will start turning red where you click it. It can take several clicks to turn the whole curve red and some parts will need repeated clicks to get the red line to fit the curve.

1939242588_Annotatcion2020-03-08134947z.thumb.jpg.cf0b3f76ae9ada9d07290768e5bf5b54.jpg

 

Make sure the whole curve is red then click the "Export" button above the blue square. This will create a text file (.txt). Right click on the .txt file and change the extension type to .frd.

 

Take the same steps for the impedance graph, but use the horizontal aqua and red lines to adjust the high and low impedance limits, the aqua and red squares on the right side of the window to put in the high and low values, and use the "Trace Z" and "Export" buttons on the right side of the window. Type the driver's impedance rating in the "Re" field on the right lower side. Use the yellow and purple lines and fields the same as on the FR graph. Rename the impedance text file from .txt to .zma.

 

Your files are now ready for X-Sim.

 

In X-Sim, drag a driver icon onto the design window, right click on the driver and click "tune", this opens a small window. For the "FRD Response File" field, click the folder, find and select your created .frd file. Do the same for the "ZMA Impedance File" and your created .zma file. Close the small window, add a trace from the amp to the driver, then add a ground to both the amp and the driver, and you should see both your frequency response and impedance files show up on the graphs. Now you can build your crossover!

1785401622_Annotatcion2020-03-081s34947z.thumb.jpg.de3c4899ab3d30f02a5de7eabc156d7e.jpg

 

 

102470550_Annotatcion20e20-03-081s34947z.thumb.jpg.cdd161e3b683b7265bb35f405b78cd6c.jpg

 

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Manually tracing a graph seems rather tedious.  Are you sure you can't simply export a text file, then perhaps delete data which is outside the intended range using a text editor (if you can't specify the range limits to export)?

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20 hours ago, glens said:

Manually tracing a graph seems rather tedious.  Are you sure you can't simply export a text file, then perhaps delete data which is outside the intended range using a text editor (if you can't specify the range limits to export)?

The most common frequency and impedance info I have been able to find are the curves in image form. The process I outline turns the image into a text file which you can use in X-Sim by changing the file extension. You can edit the text file before putting it into X-Sim. Once you learn it, tracing a curve and making the X-Sim file takes less than 5 minutes. Where can we get the text files you mention? 

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20 hours ago, glens said:

Manually tracing a graph seems rather tedious.  Are you sure you can't simply export a text file, then perhaps delete data which is outside the intended range using a text editor (if you can't specify the range limits to export)?

I think I just got what you're saying: Exporting a text file for a graph you yourself generate. If you generate the curve then you can pull a text file from it, you wouldn't have to manually trace it. I guess I should have mentioned that my process is for curve images you get from the manufacturers, or copy off of a website or even an image grab from a another forum member's post. 

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What I was thinking is that the program already has tabulated data.  It is, presumably, what it used to generate its graph in the first place.  One would think it would be optional to export that data.  If not, I believe you said it was free software.  Is only half-free or is the source code also available?

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2 hours ago, MechEngVic said:

I guess I should have mentioned that my process is for curve images you get from the manufacturers, or copy off of a website or even an image grab from a another forum member's post. 

 

I confess I hadn't read that last part before posting a few minutes ago.

 

I was thinking you were tracing graphs you'd just generated.  Got it now.

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Love your work MechEngVic!

 

Tracing is certainly one way of creating your own frequency and impedance files for X-Sim (or other tools).

 

The other way is to get a mic and a DATS/Woofer tester and make your own.

 

Relative to the cost of building/modding a system, getting the gear to actually measure is usually a small investment.

 

For all the effort you'll go to - tracing, simulating and building - getting the measurement gear means you'll be able to validate what you've done has actually worked in the end. 

 

The key for me is setting the forward lobe - where the drivers sum on the vertical axis - is the hard part. This can only be done (as far as I'm aware) by actually measuring your drivers in the enclosure you have your drivers loaded into.

 

Please don't take this the wrong way, what you've suggested is precisely how I got started. What it left me wanting was measurement data for my own built creations because I always was left wondering "how does that actually measure?". 

 

Keep up the great work! 

 

🍻

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18 minutes ago, Maz4bz said:

Love your work MechEngVic!

 

Tracing is certainly one way of creating your own frequency and impedance files for X-Sim (or other tools).

 

The other way is to get a mic and a DATS/Woofer tester and make your own.

 

Relative to the cost of building/modding a system, getting the gear to actually measure is usually a small investment.

 

For all the effort you'll go to - tracing, simulating and building - getting the measurement gear means you'll be able to validate what you've done has actually worked in the end. 

 

The key for me is setting the forward lobe - where the drivers sum on the vertical axis - is the hard part. This can only be done (as far as I'm aware) by actually measuring your drivers in the enclosure you have your drivers loaded into.

 

Please don't take this the wrong way, what you've suggested is precisely how I got started. What it left me wanting was measurement data for my own built creations because I always was left wondering "how does that actually measure?". 

 

Keep up the great work! 

 

🍻

I hear you, at one point you're gonna have to build and measure. 

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