Hey everyone. I'm having a hard time formatting my SPL data into a FRD file that PCD7 can read. I have lots of ways to get the SPL data, but so far only SPL Trace data successfully gets imported. Fuzz measure even exports FRD that appears formatted correctly but just doesn't load. Is there some mystery secret? Thanks.
Sample FRD file
Here is a sample that was sent to me by the creator of FuzzMeasure. I'm pretty sure I tried deleting the comment lines before adding to PCD as well. Anyone have any luck here? I feel like other people have FRD issues too, but no one has great solutions.
FuzzMeasure Sample.txt
Here is a sample that was sent to me by the creator of FuzzMeasure. I'm pretty sure I tried deleting the comment lines before adding to PCD as well. Anyone have any luck here? I feel like other people have FRD issues too, but no one has great solutions.
FuzzMeasure Sample.txt
wolf_teeth posted a couple of times the following link:
https://app.box.com/s/qa3g6ukzxp6410dwmcrv
I know I make my own frd's and zma's measuring drivers in the box.
It helps me understand what kind of passive parts values should I be
hoping for if I wanted to build it.
https://app.box.com/s/qa3g6ukzxp6410dwmcrv
I know I make my own frd's and zma's measuring drivers in the box.
It helps me understand what kind of passive parts values should I be
hoping for if I wanted to build it.
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For the purposes of simulation, I use SplTrace for all of my initial frequency and impedance curves. Doesn't take me more than 3 or 4 minutes per curve to get the job done but there are a few things you do to make your life easier:
1 - Be flexible with the lower frequency that you start the trace at. If you are going to splice on the box response at 150Hz or 200Hz anyways, it doesn't make much sense to start tracing at 20Hz, does it? Same applies to impedance curves depending on if and how you are manipulating them.
2 - Also be flexible with the number of points you use to make the tracings. You don't really need to use 400 data points for a fairly smooth response in other words. So I might use 50 for a partial impedance response, 100 for a full one, 100 or 150 for a partial and smooth frequency response and 300 or 350 for a full and very detailed one. Hit Trace in the upper left, click on Options, select "Use Trace Limits:" and then fill in accordingly.
3 - I don't think very many other people are still using this, but I like to use the Frequency Response Combiner to manipulate these files after tracing because it let's me resample a tiny frd file into as many points as I want to make it and because it also lets me extrapolate a curve from only a small number of data points (particularly useful for tweeters as I only need to trace a little bit of its roll-off slope and then extrapolate the rest). Needs Excel though and the learning curve is a little steep.
But if you are using measurements, you shouldn't have to worry about any of this. I'm using REW for measurements at the moment but they are saved as .txt files so I still need to rename them with an .frd file ending. You might want to give that one a try.
1 - Be flexible with the lower frequency that you start the trace at. If you are going to splice on the box response at 150Hz or 200Hz anyways, it doesn't make much sense to start tracing at 20Hz, does it? Same applies to impedance curves depending on if and how you are manipulating them.
2 - Also be flexible with the number of points you use to make the tracings. You don't really need to use 400 data points for a fairly smooth response in other words. So I might use 50 for a partial impedance response, 100 for a full one, 100 or 150 for a partial and smooth frequency response and 300 or 350 for a full and very detailed one. Hit Trace in the upper left, click on Options, select "Use Trace Limits:" and then fill in accordingly.
3 - I don't think very many other people are still using this, but I like to use the Frequency Response Combiner to manipulate these files after tracing because it let's me resample a tiny frd file into as many points as I want to make it and because it also lets me extrapolate a curve from only a small number of data points (particularly useful for tweeters as I only need to trace a little bit of its roll-off slope and then extrapolate the rest). Needs Excel though and the learning curve is a little steep.
But if you are using measurements, you shouldn't have to worry about any of this. I'm using REW for measurements at the moment but they are saved as .txt files so I still need to rename them with an .frd file ending. You might want to give that one a try.
^ jReave - Thanks for the great info! A few questions:
1 - splicing the low-end in. Can you be specific about your process here? Does this mean that you aren't taking your full range measurement with the driver in the box but taking 2 separate measurements and splicing them together? Also, what is your hardware setup for measuring impedance? I have software that can do it but don't understand how to physically get the signal in.
2 - I agree with you totally
3 - Think I get that
So are you saying that with REW you take a measurement with mic/interface, then just change the extension to FRD and it works in PCD? It sounds too good to be true. Are you opening the txt file in a program and saving as a FRD? Or straight changing the extension without opening? Thanks again for the help here.
1 - splicing the low-end in. Can you be specific about your process here? Does this mean that you aren't taking your full range measurement with the driver in the box but taking 2 separate measurements and splicing them together? Also, what is your hardware setup for measuring impedance? I have software that can do it but don't understand how to physically get the signal in.
2 - I agree with you totally
3 - Think I get that
So are you saying that with REW you take a measurement with mic/interface, then just change the extension to FRD and it works in PCD? It sounds too good to be true. Are you opening the txt file in a program and saving as a FRD? Or straight changing the extension without opening? Thanks again for the help here.
G-man,
Steps 1, 2 and 3 above are for the purposes of simulation only. Typically you take the simulated box response and splice it on to the infinite baffle response (ie. the manufacturer's curve) and then add in the simulated baffle response and then extract minimum phase. But measuring obviates the need for all of that as it is all included intrinsically in the measurement. Well almost - there is a small problem with pseudo-anechoic measurements below about 200Hz. This might help you more than I can in this regard - New-Paper-available-on-How-to-Get-Accurate-Measurements-Indoors-Down-to-10-Hz.
This may also come in handy for determining your z-offsets in PCD once you import the measurements - How-to-use-OmniMic-and-PCD-to-find-the-Relative-Acoustic-Offset&highlight=acoustic+offset.
I have lots of experience with simulations but as it is I am just now getting into the whole measurement thing so I'm currently waiting for the next version of DATS to measure impedance, but there are other ways of doing it. Others may be able to help you with that more than I can. But yes, with REW you simply have to change the file extension without opening it (just using the 'Rename' function) and then it imports fine into PCD. Maybe there's another way around that that I haven't discovered yet but as it is, it's a pretty simple change to make.
Steps 1, 2 and 3 above are for the purposes of simulation only. Typically you take the simulated box response and splice it on to the infinite baffle response (ie. the manufacturer's curve) and then add in the simulated baffle response and then extract minimum phase. But measuring obviates the need for all of that as it is all included intrinsically in the measurement. Well almost - there is a small problem with pseudo-anechoic measurements below about 200Hz. This might help you more than I can in this regard - New-Paper-available-on-How-to-Get-Accurate-Measurements-Indoors-Down-to-10-Hz.
This may also come in handy for determining your z-offsets in PCD once you import the measurements - How-to-use-OmniMic-and-PCD-to-find-the-Relative-Acoustic-Offset&highlight=acoustic+offset.
I have lots of experience with simulations but as it is I am just now getting into the whole measurement thing so I'm currently waiting for the next version of DATS to measure impedance, but there are other ways of doing it. Others may be able to help you with that more than I can. But yes, with REW you simply have to change the file extension without opening it (just using the 'Rename' function) and then it imports fine into PCD. Maybe there's another way around that that I haven't discovered yet but as it is, it's a pretty simple change to make.
jReave, thanks again. So a possible example for a short route from "nothing" to "start of simulation":
1: decide driver configuration and pick appropriate drivers
2: establish desired Vb/Ports, etc
3: build cabinet, install drivers, take SPL, phase, and Z measurements
4: PCD time
Does REW also measure phase? Do I need to make changes to the measured phase before adding to PCD? Why is manufacturer phase data not usable?
1: decide driver configuration and pick appropriate drivers
2: establish desired Vb/Ports, etc
3: build cabinet, install drivers, take SPL, phase, and Z measurements
4: PCD time
Does REW also measure phase? Do I need to make changes to the measured phase before adding to PCD? Why is manufacturer phase data not usable?
G Speakers,
Measuring the frequency response from drivers in the box will give you more accurate modelling results than using simulations. If you own Fuzzmeasure, there is no reason you should use simulation instead (at least for obtaining FRD files from the frequency response).
Lojzek is right: you cannot read FRD files from Fuzzmeasure directly because the program exports such files with negative SPL values.
Here is what I do:
1. Import the .frd file from Fuzzmeasure into Excel by reading the negative sing as a column delimiter, and skipping the first two (header) rows;
2. change the sign back to negative in the second (SPL magnitude) column and add a constant to all cells in that column (adding 110-120 works for me, but the size of the constant will depend on the level of the measurement);
3. save the resulting spreadsheet file as .txt with commas as delimiter;
4. open the .txt file with a text editor and replace commas with spaces;
5. paste the space-delimited text into the original .frd file (which you also opened with a text editor) and save;
6. the .frd file can be read by PCD or other loudspeaker modelling tools that use .frd files as it is, but it is best to extract minimum phase from the .frd file using the Response Modeler program (by extracting minimum phase, your modelling of off-axis response will be most accurate).
It is a bit of a pain to make the exported files readable in PCD or similar program (a pity given how great Fuzzmeasure is otherwise). But it works for me.
Measuring the frequency response from drivers in the box will give you more accurate modelling results than using simulations. If you own Fuzzmeasure, there is no reason you should use simulation instead (at least for obtaining FRD files from the frequency response).
Lojzek is right: you cannot read FRD files from Fuzzmeasure directly because the program exports such files with negative SPL values.
Here is what I do:
1. Import the .frd file from Fuzzmeasure into Excel by reading the negative sing as a column delimiter, and skipping the first two (header) rows;
2. change the sign back to negative in the second (SPL magnitude) column and add a constant to all cells in that column (adding 110-120 works for me, but the size of the constant will depend on the level of the measurement);
3. save the resulting spreadsheet file as .txt with commas as delimiter;
4. open the .txt file with a text editor and replace commas with spaces;
5. paste the space-delimited text into the original .frd file (which you also opened with a text editor) and save;
6. the .frd file can be read by PCD or other loudspeaker modelling tools that use .frd files as it is, but it is best to extract minimum phase from the .frd file using the Response Modeler program (by extracting minimum phase, your modelling of off-axis response will be most accurate).
It is a bit of a pain to make the exported files readable in PCD or similar program (a pity given how great Fuzzmeasure is otherwise). But it works for me.
goliardo, thanks for that walk through! It's a lot of steps but seems more reliable than what I was doing. Can you explain extracting minimum phase? Why is the recorded phase not accurate? Do you know if the program can extract minimum phase from a file that doesn't have phase information? (I am most proficient with SMAART but a single channel measurement doesn't include phase data)
Phase is simply a function of the frequency response (FR). Programs like Frequency Response Modeler or Frequency Response Combiner I linked to earlier mathematically extract it in a handful of seconds from either a simulated or measured FR. And since the FR is going to change when you put a driver on a baffle and in a box, manufacturers don't include phase in their charts. Dayton includes impedance phase but that's something different.
So your 4 steps to design are more or less correct. After step 2, I will usually run the drivers through a complete simulation to get a ballpark idea of what the xo is going to look like - some drivers go together well and some just don't want to line up at all, and then that might make me change a few little details, or not. Actually, I usually end up doing this with a number of driver choices to see which ones work best.
And then after PCD simulation, you need to implement the xo, listen, test, tweak and repeat. And you might want to listen for a week or a month even before making that one little change that finally makes it right.
When you get back to PCD btw, turn off 'Total Phase' and turn on 'Driver Phase' in order see the driver's phase and then to be able to correctly align the phases at the xo points. Total phase won't help with this at all. Invert polarity on your mids as a method of checking for the reverse nulls which are the by-product of good phase alignment. Wouldn't hurt to look at the power response as well.
So your 4 steps to design are more or less correct. After step 2, I will usually run the drivers through a complete simulation to get a ballpark idea of what the xo is going to look like - some drivers go together well and some just don't want to line up at all, and then that might make me change a few little details, or not. Actually, I usually end up doing this with a number of driver choices to see which ones work best.
And then after PCD simulation, you need to implement the xo, listen, test, tweak and repeat. And you might want to listen for a week or a month even before making that one little change that finally makes it right.
When you get back to PCD btw, turn off 'Total Phase' and turn on 'Driver Phase' in order see the driver's phase and then to be able to correctly align the phases at the xo points. Total phase won't help with this at all. Invert polarity on your mids as a method of checking for the reverse nulls which are the by-product of good phase alignment. Wouldn't hurt to look at the power response as well.
Creating FRD with REW5 for PCD7
jReave, I downloaded REW5 and it seems to be a pretty great program. But my issue still persists here. I made a measurement, exported as text, deleted comment lines and saved as .frd But PCD still doesn't want to open it. Anyone have a suggestion?
REW Test2.txt
jReave, I downloaded REW5 and it seems to be a pretty great program. But my issue still persists here. I made a measurement, exported as text, deleted comment lines and saved as .frd But PCD still doesn't want to open it. Anyone have a suggestion?
REW Test2.txt
I don't know why the formatting is all screwed up in your file but it is. I've attached one of my saved files below for comparison.
In 'File' -> 'Export' -> 'Set text delimiter' -> I have mine set to 'Space', but I just tried every other setting and they all still open up fine in PCD.
So let's go step-by-step:
1) File
2) Export
3) Measurement as text
4) Measurement data notes -> OK
5) Name as you wish; 'Files of type:' -> select 'Data (.txt, .frd, .dat, .zma, .csv); and Save wherever you want to. Open the file now to see if the formatting looks like your previous file or the one that I attached. If you are getting the same result as previously, then I have no idea why - someone else more knowledgeable than myself will have to chime in.
6) Right click the file and select 'Rename' -> change .txt extension to .frd (There is no need to delete the text info at the top - it still works fine with it included)
And that's it. For me, that imports into PCD without problems. It also imports into Response Modeler and Frequency Response Combiner as well.
Hope that helps.
In 'File' -> 'Export' -> 'Set text delimiter' -> I have mine set to 'Space', but I just tried every other setting and they all still open up fine in PCD.
So let's go step-by-step:
1) File
2) Export
3) Measurement as text
4) Measurement data notes -> OK
5) Name as you wish; 'Files of type:' -> select 'Data (.txt, .frd, .dat, .zma, .csv); and Save wherever you want to. Open the file now to see if the formatting looks like your previous file or the one that I attached. If you are getting the same result as previously, then I have no idea why - someone else more knowledgeable than myself will have to chime in.
6) Right click the file and select 'Rename' -> change .txt extension to .frd (There is no need to delete the text info at the top - it still works fine with it included)
And that's it. For me, that imports into PCD without problems. It also imports into Response Modeler and Frequency Response Combiner as well.
Hope that helps.
jReave, I've finally got it! After months of avoiding entering each data point, or at least clicking on it with SPL trace, I found a method. My problem was that I was running REW in Mac, and everything else in windows. So the text file would look fine in OSX, go to windows and convert to FRD and its already jacked.
Solution:
Since I can't get any of my 3 audio interfaces (thanks windows running on mac) to work in windows, I take measurements in REW on the Mac side, save them, then open them in the Windows version of REW, then export as you said, rename, and viola! It takes PCD a long time to open it, but it works!
That being said, I do realize that my main issue with this project was my measurement data not being taken properly. I have move my speakers away from boundaries, and seem to have data that makes more sense. I'll be posting on another forum about current issues, but you have helped me cross a huge hurdle, thank you.
Solution:
Since I can't get any of my 3 audio interfaces (thanks windows running on mac) to work in windows, I take measurements in REW on the Mac side, save them, then open them in the Windows version of REW, then export as you said, rename, and viola! It takes PCD a long time to open it, but it works!
That being said, I do realize that my main issue with this project was my measurement data not being taken properly. I have move my speakers away from boundaries, and seem to have data that makes more sense. I'll be posting on another forum about current issues, but you have helped me cross a huge hurdle, thank you.
FIY I don't have to right-click to change file type, I just type in the .frd extension when exporting and it works fine.
Do you use the phase data measured from REW or send the FRD through response modeler and extract phase? It looks like REW will let me lock time=0 which seems like it would give me more reliable phase info for simulation.
Do you use the phase data measured from REW or send the FRD through response modeler and extract phase? It looks like REW will let me lock time=0 which seems like it would give me more reliable phase info for simulation.
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If PCD is running very slowly for you, try WinPCD. It started as a pure emulation of PCD with info from Jeff Bagby, but it's diverged quite a bit in the GUI side and some functionality. It's far from complete at this point, but the 2-way and 3-way sections are complete.
It is written to target .NET 4.0, so it should automatically download and install that. Details are at the site in my signature below.
dlr
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