Forum Replies Created
12 November 2022 at 5:43 am #587
>> Thanks for the explanation it all make sense,
>> Side question is there any chance the time IR accept files with 3 column and
>> ignore the 3rd one? Many software export with a 3rd imaginary column and it
>> would be nice to not have to modify the file every time to import in FIR designer.
>> See attached example. Or did I miss something.
>> Thanks a lot
Our 3+ column TXT import by default assumes freq|mag|phase|coherence.
We do some checking of the file for specific formats that can be inferred from header or comment text, but without any headers or comments, we assume freq|mag|phase|coherence.
>> Many software export with a 3rd imaginary column
I have never seen anything like this before, but since the header text is
Time[s] Real[V] Imag[V]
we could write a customer importer for this. I’ve added this to the TODO list but I can’t say when it will be ready.
EA Support2 November 2022 at 6:44 pm #583
>> Is there anyway to convert this response file using FIR Creator EX?
>> I don’t know how to change it to 0 dB.
You don’t need to have the measurement at around 0 dB. The “Import” tab has the gain adjustment for exactly this purpose.
I have taken a look at your FDP file. Here are a few suggested minor adjustments:
– On the “Mag Adjust” tab, change the gain of the “High Shelf” to -7.9 dB.
– On the “Auto Mag” tab, change the “Min Freq” to 90 Hz.
>> I imported a speaker response and created a fir file. But the result seems hardly doing anything.
From what is shown on the “Export” tab, the FIR filter should definitely be audible.
All I can suggest is checking that the processor is importing the file and that the filter is enabled. What processors are you using and what FIR filter format did you export?
EA Support1 November 2022 at 7:08 pm #581
Regarding the -108.1 dB gain, with “Normalise magnitude to max” checked, the Import tab looks for the peak in the measurement and shifts the response so that the peak is at 0 dB. The FIR Creator workflow needs the response to be around 0 dB. (Maybe your measurement magnitude response has units of dB SPL and your mic was close to the loudspeaker.)
Regarding your FIR filter, provide a screenshot of the Export tab and a link to you project *.fdp file.
EA Support20 October 2022 at 2:48 pm #576
Crown itechHD’s require a specific number of coefficients. The last we checked, it was 897, but it might have changed. You may need to try different files with different numbers of coefficients until it works.If you still can’t get it to work, I suggest contacting Crown. They may have a problem with the FIR loading.
Regarding precision, your 2nd screenshot shows that the coefficients do match. It’s just that the iTech display is rounding/truncating at 6 decimal places, which equates to approximate -120 dB relative to full scale; so I think you’ll find the trunction doesn’t matter.
EA Support19 October 2022 at 6:36 pm #574
The region around 150 Hz has fairly high phase slope at import and it looks like the tabs, prior to the Phase Adjust tab, have added additional phase slope; which looks to be from HP filtering. The result is a phase slope high enough that it’s marginal*, in the plotting, between showing a step between plot points (as in your screenshot) and wrap. Given that this freq region way out of band – it looks to be at approximately -60 dB relative to the passband – it’s safe to ignore.
* The plotting groups/averages the >16000 raw FFT data points into a smaller log frequency spaced set at approx. 1/96th oct spacing. Sometimes in this averaging, very high phase slope regions can go either way.
EA Support16 October 2022 at 10:07 am #571
The Target response import loads almost all of our supported formats, including CSV. See Text and CSV on:
If your CSV is a magnitude curve, ensure your CSV file has 3 columns; frequency (Hz), mag (dB) and phase (degrees). The phase can be set to 0.0.
EA Support13 September 2022 at 6:25 pm #565
We’ll take a look but can’t promise any changes to address this. Odd handling of “.” in filenames is a problem shared by many apps; not just ours. All I can suggest for now is to not use “.” and instead use something else like the underscore. For example “filter_xyz_V0_2”. I do this myself in other apps.
EA Support8 September 2022 at 11:18 am #563
>> Do you have a proper workflow how to achieve a 2- or 3-way System with a linear phase from about 100 Hz to 15 kHz?
The 2-way tutorial on the website shows how to use the FIR filtering, in particular the Auto Mag and Auto Phase, to force each loudspeaker driver toward a target response; which in your case would be linear-phase high-pass and low-pass responses.
>> Is there a possibility to show the step response of the hole speaker system?
Not in FIR Designer M at the moment. However the Wavelet display (in Second View) shows the response of the whole system and you can use this to confirm that the system is tending towards a symmetric, vertical line (which flares both sides at lower frequencies), indicating a pure impulse which, by definition, gives the step response you are looking for.
EA Support7 September 2022 at 6:46 am #557
What you’re expecting is what happens when the LF rolloff is minimum phase. What is shown is what happens when the LF rolloff is linear-phase.
To investigate the effect more, run FIR Designer without any loudspeaker measurement on the Import tab, then put a HPF filter either on the IIR filters tab or the Mag Adjust tab. If using the Mag Adjust tab, try minimum and linear phase and watch the effect on the step response. Examples below.
BTW In your screenshots, check “Show FIR Filtered loudspeaker” to see all filtering applied to the measurement. This is what is used to create the step response.
6 September 2022 at 6:51 am #553
- This reply was modified 2 months, 3 weeks ago by EA Support.
>> Unfortunately we experience Audio architect to not read the FIR (csv) file.
>> Audio Architect gives the error message “An Incorrect Number of coefficients were entered.”
>> Find attached csv file exported according to your instruction (897 samples) + the message from Audi architect.
>> Can you test my attached file?
It’s possible Crown have changed something and require a different number of coefficients. Either export the file again with fewer taps or edit the CSV file in a text editor to remove some lines. Repeat until the error message goes away. Note the last coefficients in the file are 0.0 anyway.
From your screenshot, Audio Architect is reading the coefficients and displaying them. It’s just the Apply button that triggers the error message.
(Your file loads correctly for us into “I-Tech HD series” and doesn’t give the error.)
>> Some questions.
>> In FIRd I have the sample rate set to 48kHz. Will this influence the exported coefficients?
>> Maybe the DSP in Crown HD amp need to have the same?
Changing the sample rate in FIR Designer will affect the values of the coefficients, but not the number of coefficients or taps.
As so what sample rate to use, that’s a question for Crown. It’s most likely 48 kHz.