Dayton includes impedance phase but that's something different. 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. 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. Phase is simply a function of the frequency response (FR). 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). frd file using the Response Modeler program (by extracting minimum phase, your modelling of off-axis response will be most accurate). frd files as it is, but it is best to extract minimum phase from the. frd file can be read by PCD or other loudspeaker modelling tools that use. frd file (which you also opened with a text editor) and save Ħ. paste the space-delimited text into the original. txt file with a text editor and replace commas with spaces ĥ. 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) ģ. frd file from Fuzzmeasure into Excel by reading the negative sing as a column delimiter, and skipping the first two (header) rows Ģ. Lojzek is right: you cannot read FRD files from Fuzzmeasure directly because the program exports such files with negative SPL values.ġ. If you own Fuzzmeasure, there is no reason you should use simulation instead (at least for obtaining FRD files from the frequency response). Measuring the frequency response from drivers in the box will give you more accurate modelling results than using simulations. 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. 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. Others may be able to help you with that more than I can. 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. 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. 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. Well almost - there is a small problem with pseudo-anechoic measurements below about 200Hz. But measuring obviates the need for all of that as it is all included intrinsically in the measurement. the manufacturer's curve) and then add in the simulated baffle response and then extract minimum phase. Typically you take the simulated box response and splice it on to the infinite baffle response (ie. Steps 1, 2 and 3 above are for the purposes of simulation only. txt files so I still need to rename them with an. I'm using REW for measurements at the moment but they are saved as. Needs Excel though and the learning curve is a little steep.īut if you are using measurements, you shouldn't have to worry about any of this. Hit Trace in the upper left, click on Options, select "Use Trace Limits:" and then fill in accordingly.ģ - 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). 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. You don't really need to use 400 data points for a fairly smooth response in other words. 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.Ģ - Also be flexible with the number of points you use to make the tracings. 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:ġ - Be flexible with the lower frequency that you start the trace at. For the purposes of simulation, I use SplTrace for all of my initial frequency and impedance curves.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |