I do think something is wrong with his copy of REW, or something else is weird there.
I will update REW and also repeat the process from scratch. I let you know. Thank you (and linuxonly as well) for your support!
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Here are my preference screens for reference. I may need to include these in the guide.
Amazing! This information is all good to know. I'm glad you were able to work through it.I will update REW and also repeat the process from scratch. I let you know. Thank you (and linuxonly as well) for your support!
I FOUND THE PROBLEM ... and the problem were my measurements
- I measure up to 24kHz. Thus, my exported 1/12 smoothed measurement contained data above 22kHz.
- After I deleted any data above 22kHz from the data, the whole process worked like a charm and A/B with Target-MP/Measurement-MP delivered an IR
Finding this problem took me a few hours of testing, trying and playing around. But now I was able to generate the first filters according to your document (which is excellent by the way!). I was also able to generate a smoothed measurement with 1/12 smooting up to 225Hz and 1/6 smoothing above 225Hz. I had a short listen and it sounds great (controlled bass with punch and ease, great imaging and stage, no signs of ringing, low latency, a 16k filter also seems to work without quality loss in my scenario).
I will experiment with a few targets and measure the results (after some sleep).
Thanks again for sharing this
. I use very similar preferences. Is it important in your workflow(s) to "Keep full IR" and to "Set window widths automatically"?I continued some listening today and I am really impressed. I also used your target settings which sound very well balanced!
Hey, thanks a lot. Very useful. Had to deviate a little. Not sure if it's because it's the linux version of REW, I'm using the current one. No beta.
This paper may be of interest...
Thanks, for the hint to the paper. More reason for me not to touch the highest frequencies and let them live
. However, I assume that these frequencies are typically cut in the music production process. I need to check some more information about digital mastering and what is typically done for frequencies beyond 20k.
Doing that will produce very large measurement files with much of the additional retained impulse response being noise floor.
Hmm, could you tell me more? Why 22kHz is important? Why not 21 or 18? On my Debian computer, I sample at 48kHz, measure from 1 to 24kHz and have the same problem, no data to export because there is no impulse data. What's the exact procedurte you took to fix this, and how to avoid it in the future. I'm tired redoing everything from scratch on that computer.
This should not be related to John's comment about "Keep Full IR". But John would probably be able to explain the behaviour of the trace arithmetic when your input data exceeds 22kHz. It might be a bug but there might also be good reasons for it. In the later case, it would be extremly helpful to output a short warning message. I just stumbled upon something comparable in the Equalizer APO convolver. It is somehow limited to convolution up to 22.050 Hz and is doing some weird manipulations when your filter has no roll-off.
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... and a lot of manual work. It is not only copying the right data from several exports into one file. After that, I also have to look at the transitions between the areas and smooth them seperatly, if they are too edgy. Anyway, I am having fun with some R&D 
I know, I am fiddling around and try to build a version optimized for (my) room correction
. Results are getting more and more similar ... not ready to tell yet, if I put too much effort into this.
I think you will find that there are many recording/tracking, mixing and masterings done at 48kHz... Up and/or Down sampling for release to 44.1 kHz at 16 bit and up to 32 bit 196 kHz for other formats such as high rez downloads and streaming services like Qubuz...Thanks, for the hint to the paper. More reason for me not to touch the highest frequencies and let them live
Excellent research work!The method works great with different smoothings. It produces FIR filters with excellent sound quality and low latency. I love it!
Additional remark: I have also looked at the phase, distortion, impule, clarity, waterfall, spectogram ... they are all very similar.
- I will most probably go forward with the variable smoothing from REW and rather look for finetuning of the target. I like the proposed 0,4/0,4 target. It is a good starting point.
Honestly I have had it set that way for a very long time. I can't remember exactly what the reason was. I think it is more important to leave decimate IR off. If truncate after 1.7 works and has no audible effect, then use that.Thanks for sharing
It is variable, but it is not customizable. Having the ability to configure it with custom smoothing levels would be awesome.
I think I will. In the meantime, here's a workaround that doesn't require editing txt files. It doesn't interpolate the values across the spectrum, but it does at least blend the two values together at a definable frequency over a very small fixed range. Unfortunately, we can't define the blend range, but at least we have something.
Hi,
