Forum Replies Created
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3 June 2025 at 12:29 pm #1053Hi richardsllc,
I’ve receive the files and looked them over. Here’s some initial thoughts.
I had assumed that you had obtained magnitude and phase measurements of the processing for an existing EV preset, and that you were trying to replicate this processing using IIR, FIR or IIR+FIR. (This is very straight forward with FIR Designer M and a safe path for getting a good result, benefiting from all the manufacturers expertise.) However the files appear to be individual driver measurements of a cabinet (or cabinets).
Before I talk about the FIR Designer M system files, I need to talk about making presets. Designing multi-way presets, particularly for pro audio cabinets, involves optimising many factors including response on axis, response in different directions within a desired coverage angle, consistency of directivity across frequency, and system robustness at high levels. For example a DSP design which gives a good on axis response at low levels could damage a driver at high levels or (if using limiters) cause some drivers to limit earlier than others (causing dynamic fluctuations in response and directivity). This may then require moving crossovers higher in frequency – to reduce the burden on the MF or HF – which then affects directivity, and so on, and so on. All this to say, I would be very nervous trying to make a preset from on axis measurements, without having the ability to measure the system at other angles (e.g. using a turntable or multi-axis robotu) and without being able to test at high levels (and be willing to burn drivers).
Anyway… regarding your FIR Designer M system file.
IMPORT tab
The measurements you provided all have a time offset of roughly 9.5ms but the offsets are not all the same. Were the measurements captured with a common timebase, or are they completely independent? The slight time delay differences seem to match the different physical depths of the drivers from a XVLS photo I found online, but it’s important to be sure. If they weren’t captured with a common timebase, then you will need to take more measurements.
In FIR Designer M, the ~9.5ms delay is present in the loaded measurements in each channel. If you remove this delay, much of the high phase slope goes away, making the workflow easier. For example, on the Import tab “Delay Adjustment” “Delay: samples” to -458 samples.
For each channel, turn on “Hide phase” and for LF set “>” to 1000 Hz, for MB set “>” to 5000 Hz and for HF set “<” to 200 Hz. Now the magnitude and phase plots become easier to view as you work through the workflow.
GAIN/POLARITY/DELAY tab
All channels have some non-zero delay. The G/P/D tab is about adjusting the alignment between the channels. Any delay common to all channels is just bulk delay added to the whole system, which isn’t necessary and can be removed.
IIR FILTERS and FIR tabs
There are IIR HPF and LPF filters enabled AND HPF and LPF filter prototypes enabled on the Mag Adjust tab. These are causing major problems with the preset. Choose one or the other, but not both. Generally HPF and LPF filters are more efficient and effective as IIR filters, leaving the FIR to deal with more delicate mag and phase adjustment. If you definitely want linear-phase crossover HPF and LPF’s, then turn off the HPF and LPF filters in the IIR filters tab.
The Auto-phase that is enabled on the HF is unnecessary. It’s just trying to undo bulk delay and wasting FIR taps.
I have just emailed you two new systems. One is IIR only and the other is FIR only. Please study them carefully in terms of how to use the workflow, but don’t rely on the actually settings… see the “Before..” paragraph above. 🙂 Our support is focused on how to use the software.
Regards,
EA Support
30 May 2025 at 1:33 pm #1050Please send your text file, the FIR Designer M system file that you have created, and your FIR Designer M license ID number to the email address ‘info (at) our website name’.
(Note, here you’ve replied to a different topic. Best to either reply to the previous topic that you started, or create a new topic.)
Regards,
EA Support
22 May 2025 at 4:06 pm #1045Version 4.4.2 is now available and fixes the issue.
Regards,
EA Support
22 May 2025 at 4:06 pm #1044Version 4.4.2 is now available and fixes the issue.
Regards,
EA Support
22 May 2025 at 9:51 am #1042Ok, we’ve found the problem and it has nothing to do with the sample rate. We need to chase this issue with Rational Acoustics as it’s something inherent in the TRF measurement at very high frequencies. Like I said above, below 20 kHz, everything is ok so you can continue with the filter design process.
Regards,
EA Support
22 May 2025 at 8:24 am #1040Files received, thanks. The magnitude, phase and coherence of the file is loading correctly, so you can continue through the FIR Designer M workflow as normal. The issue appears to be in the sample rate conversion from the file’s 44.1 kHz sample rate to the FIR Designer M channel sample rate – e.g. 48 kHz – and only affects frequencies near the half Nyquist frequency (22.05 kHz to 24 kHz). Note: if you set the channel sample rate to 44.1 kHz, the impulse response is clean.
We’re looking into this now.
Regards,
EA Support
21 May 2025 at 7:37 am #1038Hi hulkss,
Please email a few of the TRF files to info (at) our website name, along with a screenshot of what you see in SMAART, and we’ll take a look.
Regards,
EA Support
17 May 2025 at 9:04 pm #1035Hi Bido,
Firstly, the filter length of 400 samples at 48 kHz (8.3ms) is much too short to achieve the magnitude changes and phase correction that you’d like. Take a look at the “FIR Filter Frequency Response” and “Total Error” graphs in your FIR Creator project. To achieve the EQ your desire, particularly at 100 Hz, you need a FIR filter length closer to 2048 samples with a delay of ~400 samples. Take a look at Section 5 on https://eclipseaudio.com/fir-filter-guide/
Secondly, looking at the original measurement – your 1st Smaart screenshot…. The phase rotation at ~760 Hz is an acoustic cancellation – most likely from a reflection – as evidenced by the corresponding dip in the magnitude response and dip in the coherence. No amount of DSP (in magnitude and/or phase) can fix this. Just considering the magnitude response, if you try to boost this with EQ, very little will change when re-measured. In your case, adding the 2nd order phase rotation in DSP is just widening the acoustic cancellation region. (Try removing the 2nd order phase filter and the remeasure, and I think you will see a mag dip similar to the unprocessed measurement.) The other frequencies where the coherence dips – e.g. 90 Hz, 390 Hz and 440 Hz – also correspond to magnitude dips which look like cancellation effects, likely from reflections.
DSP can address phase effects inherent in the loudspeaker, like from crossover filters, but little can be done about cancellation from reflections.
Best regards,
EA Support
7 May 2025 at 7:30 am #1031Dual-column files are assumed to be impulse response time samples, where the 1st column is the timestamp and the 2nd samples, which is why they aren’t importing correctly for you. See
The quickest solution I can suggest is to load the TXT file Excel or Google Sheets, add a 3rd column of all zeros (for phase), then export as a new TXT file or CSV. (You might need to select just the active cells, prior to export.)
If that doesn’t work, email your TXT file to info ‘at’ <our website> and we’ll take a look.
Regards,
EA SupportI tried to attach one of the files FYI, but this portal doesn’t seem to allow it
FWIW you can put the file on one of the file-sharing websites, or dropBox, and include a link in the forum message.
30 April 2025 at 6:26 pm #1028ok, thank you for quick reply
We use usually rephase, but for a project we need chebyshev filter type 1 for crossover use, in minimum phase FIR format,, it is possible?Yes, to create a Chebyshev equivalent FIR filter, use the ‘FIR: Magnitude Adjust’ tab in FIR Creator EX. You can try this in the demo mode. However, since you mentioned minimum-phase, it’s much more efficient to implement this using IIR biquads.
For export IIR coefficient we need FIR Designer or Creator is ok?
The FIR Creator EX ‘IIR Filters’ tab can be used to generate biquad coefficients, which can be exported from that tab.
Please download the demo version and experiment with all the tabs in the workflow.
To learn more about the workflow, see the first two ‘FIR Designer’ videos on:
https://eclipseaudio.com/fir-filter-design-tutorial/About audio quality, are there differences in quality for the same filter between Fir Creator and Rephase?
Thank again
Best regardsNo. The perceived ‘quality’ of FIR and IIR filter processing relates to the design choices in creating the filters, not the choice of program.
Regards,
EA Support
23 April 2025 at 12:28 pm #1026Yes the FIR filter needs to be designed and exported for the sample rate that the processor/amp uses for FIR filters. (I don’t know the specifics w.r.t. Linea Research amplifiers.)
Some 96kHz processors run their FIR filters at 48 kHz, so the FIR filter needs to be designed for 48 kHz (and not the core 96 kHz). And Lake uses 12kHz, 24kHz and 48 kHz for FIR filters, even though the input processing runs at 96 kHz.
In our products, if you have a design created for a particular sample rate, you can easily export for a different sample rate by first changing the “design sample rate”.
Regards,
EA Support
20 April 2025 at 9:11 pm #1024We have many things we are working on so we can’t give an ETA at this time.
Regards,
EA Support
28 March 2025 at 6:08 am #1015>> My backup plan is to use the latest IIR presets, which I have used for years and
>> like the sound, feed them into FIR Designer-M, and create new, similar, but phase-linear versions.You can recreate the presets from electrical measurements, however I would NOT convert each channel to linear-phase. The phase differences between channels in the multi-way are part of the preset and are inherent in making the preset work. If you change these relationships, you could dramatically alter the system’s response and directivity in and around the crossover region.
As for making the combined acoustic response linear-phase, in addition to electrical measurements of the preset, you would need some reliable or meaningful acoustic measurements.
Regards,
EA Support
27 March 2025 at 7:21 am #1013The SPS files appear to be proprietary binary preset files. We can’t load or open these.
You could try loading each of these presets into a EV processor, then turn off all the IIR filters and crossovers (leaving just the FIR filters running) and then electrically measure the FIR filters at the outputs of the processor. From this, you can use the process described above to generate new FIR filters.
We’re a small company and don’t have the resources for individual phone support. If you have a measurement, we can show you the workflow (with screenshots) to then do more conversions yourself, but it sounds like the main issue right now is actually getting at or measuring the FIR filters.
Regards,
EA Support -
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