Creating convolution files for Roon in the new Room EQ Wizard (REW) with Inversion

One thing I forgot: can I use REW version 5.20.10 for Mac or would this method with speaker response inversion only get good results with version 5.20.11, as you suggest? (there is only a version for windows, right now, as far as I see?)
by the way, what are the differences between these two versions of REW?

Very nice method you have developed Serkan… Thank you for sharing with the community…

Cordially,
-DD-

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This Mac version has everything you need:

https://roomeqwizard.com/installers/REW_macos_5_20_11.dmg

I just meant the “LF cutoff” of your target curve simulation in EQ screen will be lower than a system without subs. My speakers start from around 34 Hz, your combined system will probably start closer to 20 Hz. You cannot really permanently damage anything with a wrong convolution so feel free to play around with different settings.

ok that’s obvious, think my subs go down to around 25Hz in specs or so. I will take care to fit that with my measurement.

nice, thank you so much Serkan, I will try it out!

Hi Serkan,
next question from me before I can start a measurement:
Is der any reason, why you choose 90 degree measurement-angle for your mike? because I have read 90 degree are for home cinema multichannel setups, wouldn’t be 0 degree from listening-position better for stereo?
thx again

Looking forward to trying this out.

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Thanks for this tutorial, I will try it out next week. I just need to get a mic stand. I’ve used Magnus’ moving microphone method this far and mic stand wasn’t needed.

One question. In the beginning you recommend to adjust the mic at the height of the tweeter. I use 3-way ATC speakers which have their acoustic axis at the height of the midrange driver or 5 degrees under it. Shouldn’t I position the mic in the middle of the midrange driver then?

Thanks very much for sharing @OCA. I’ll try it out with my setup.

Why does the inverted filter not correct for the dips in the modulus curve, but only for the peaks? If I understood your explanation correctly, you only use the measurements and the target and REW for the calculations, so everything should be ideal in your example. Are the recurring dips a consequence of the conversion to minimum phase?

0 degree is better only when the mic points directly towards the speaker and you cannot achieve that for both channels without moving the mic and when you move the mic you lose all the measurement accuracy in terms of distance and phase.

Magnus’s methods are cheap :slight_smile:

I don’t know if your ATC’s have a very special design but majority of speakers are designed to sound their best when their tweeters are at ear level.

“exclude notches” option in “1/A” trace arithmetic is forcing the operation to cut all the inversion peaks which are the corrections for the dips in the measurement. We cannot correct the dips because they are not minimum phase (yes despite the forcing to min phase by measurement actions - hence the option) and non minimum phase cannot and should not be inverted. They are also very location specific unlike the peaks so correction wouldn’t be valid at any other point other than the LP even if we manage to correct them. Acoustic treatment is your best option to deal with them. Good thing is unlike the peaks, narrow dips, no matter how sharp, are mostly inaudible to us. Btw, it’s an option, so feel free to untick it and share your results with us!

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Hi @OCA
Can the filter settings (the Wav files) be exported into the miniDSP SHD? I connect my CD player and also my TT to the the Preamp and the miniDSP SHD is between the preamp and the power amp ( SimAudio Moon 390 / 330A setup) and would like to have all my sources go through the DSP correction.
Thanks

I checked SHD and it seems to accept only EQ filters (a total of 6 filters either in PEQ or biquad format) from REW so it will not process wav type convolution files. The unit seems to have its own Dirac Live room correction system though and you can use that for any sources outside of Roon.

I guess the design is special then since 3-way ATC’s are designed to sound best with midrange driver at ear level. So I guess I would measure at that height since they are adjusted so that the midrange driver is at my ear level(?)

Here’s a screenshot from the manual.

Hi Serkan, one important question again:

am i unterstandig it right from your video, that I have to adjust the time alignment and the SPL of the speaker manually (either in Roon or at the back of my aktive speakers), or is this also be done by the convolution filters, that I get in the end (and saved there??)? Or do I have to do both? I also use Roon like you, can you explain to me, where exactly I change the delay of each speaker and the SPL in Roon?

thank you!

ok, understood :+1: thx

Hi Serkan, thanks a lot for sharing this method!
I completed the measurements yesterday evening and will go through the corrections in REW today. Happy to share my impressions afterwards.

One thing I noticed is that when I wanted to repeat the measurement of the left speaker, there was quite a bit of distortion - the sweep didn’t play smoothly. Could this be a sign that I need to dedicate more RAM to REW? At the moment, I have 1.5GB reserved for it, but I remember reading at installation that more RAM might be needed for long sweeps…

Correct!

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