Possible new tool to get T/S from *.zma

[rone]

I've been playing around in excel, working on a tool to extract T/S from impedance data. Is this something of interest to people? Still a work in progress...

http://www.flickr.com/photos/9171790...7627333634683/

[Chris Roemer]

I've been playing around in excel, working on a tool to extract T/S from impedance data. Is this something of interest to people? Still a work in progress...

very interesting

[rone]

How about a wishlist, then?

[Jeff B.]

I've been playing around in excel, working on a tool to extract T/S from impedance data. Is this something of interest to people? Still a work in progress...

http://www.flickr.com/photos/9171790...7627333634683/

I have one too. I posted this back in January, but no one responded to it, so I didn't take it much further.

http://techtalk.parts-express.com/sh...63#post1705463

How did you choose to approximate Re, if I may ask. That was one of the things I had to give some thought to.

Jeff

[rone]

Right now it is just a simple curve fit with a speaker workshop style model (series Le and Re with a parallel L-R combo) in front of the notch. I haven't done any testing - this is one of my one hour wonders at the moment - so I haven't run into any issues other than convergence. Rdc came out to within 0.07 of measured Rdc with the fit.

"Re" is an issue because the impedance at Fs (ignoring the motional impedance) is not just Rdc as assumed in standard theory when ignoring inductance.

I am currently exploring multiple methods of measuring T/S parameters and will be working on verifying the system identification process.

I can't seem to follow your link, some issue with permissions.

[Wolf]

I have one too. I posted this back in January, but no one responded to it, so I didn't take it much further.

http://techtalk.parts-express.com/sh...63#post1705463

How did you choose to approximate Re, if I may ask. That was one of the things I had to give some thought to.

Jeff

That's why nobody saw it, Jeff- It's in the Beta-tester forum. I would like to have that spreadsheet in my arsenal for certain. I don't peruse that forum hardly at all, since it's inception and actual beta-testing.

I knew you'd thought about it from other TT posts, but I wondered why I never saw anything...

Later,
Wolf

[Jeff B.]

That's why nobody saw it, Jeff- It's in the Beta-tester forum. I would like to have that spreadsheet in my arsenal for certain. I don't peruse that forum hardly at all, since it's inception and actual beta-testing.

I knew you'd thought about it from other TT posts, but I wondered why I never saw anything...

Later,
Wolf

I took a day or so to set up the macro and spiff up the user interface. Here is a screen shot of my tool. You import the zma file and it automatically calculates the basic parameters. If you enter the Vas and the piston diameter it will calculate more advanced parameters. It also displays the file you imported, which can help keep thing straight.

Is there anything else that this needs?

[rone]

Your UI looks nice, Jeff! It would be nice if it showed the fit, though.

I was planning on a tab for free air and tabs for delta mass and delta compliance to cross check parameter results from other programs.

I was going to do full impedance workups for sealed and vented to generate estimates for Qa, Ql, Qp as well.

[rone]

Jeff, just testing my sheet, what does your sheet give for part number 296-616?

I got:
Fs 33.73
Qms 2.774
Qes 0.606
Qts 0.497
Re 6.1882
Le 1.43E-04
R2 4.4943
L2 4.29E-04
Res 28.3385
Lces 0.0482
Cmes 0.0005

Speaker workshop gives:
Fs 33.804
Qms 2.812
Qes 0.608
Qts 0.500
Re 6.141
Le 1.00E-04
R2 8.136
L2 1.88E-04
Res 28.41
Lces 0.04756
Cmes 0.000466

[Wolf]

Looks great, Jeff!
Wolf