I don't use REW myself, can't help with the specifics, but the left edge of the time window should be always rectangular, otherwise you risk gross errors. It's best to see the actual window plotted in the IR graph (HOLMImpulse seems still unsurpassed in this regard).
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Kimmosto recommends using Tukey 0.5 windows, as it provides better tracking with (true) nearfield or ground plane response. He posted a comparison somewhere, but I don't have it at hand; only an excerpt from VituixCAD manual.
Your left window is too short, it need to include full impulse. Increase from 2 to 4 or 5 ms. Right window is OK, can be increased from 12 to 13 ms.
REW does it too, and more: it shows you FR in real time as you drag windoow cursors.
IMO, with recent updates it has surpassed all other measurement software, you should really try it.
Good to see that. Of course if you include the full impulse with a sufficient time margin before it actually starts, the shape of the left window edge becomes virtually irrelevant. But you must be sure this is the case.
"it shows you FR in real time as you drag windoow cursors" - yeah, that's was the great feature of HI for years. It's great that REW does it as well now, it's really extremely useful.
"it shows you FR in real time as you drag windoow cursors" - yeah, that's was the great feature of HI for years. It's great that REW does it as well now, it's really extremely useful.
Well, an impulse always starts where it starts to deviate from zero...
How many zeros are included before the start is irrelevant. (It can affect calculated phase (delay) though - that depends on how it's implemented. Here it seems that the time reference for where the IR actually starts can be set independently of the window.)
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So it should be fine.
Yeah, but that shouldn't affect the calculated DUT response much. One doesn't have to be absolutely precise anyway - what's criticial is to have it consistent time-wise for all the drivers in the system. But in absolute terms, it doesn't really matter.
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Now we are back at the Circle of confusion. One just can't avoid the thought whether a device that would stay flat on-axis but with the same power response slope wouldn't be actually better. You are in a position now where you can "easily" try both. That would be quite an experiment!
(BTW, I don't say it would be better, I just don't know. There are good theoretical arguments for either.)
Wait, I didn't get good measurements. I used acoustic time reference because I don't have proper testing equipment and I didn't make sure each driver measurement was the same distance between the microphone and the acoustic reference. Apparently, when I moved the microphone to the next driver I was supposed to make sure the distance between the mic and the acoustic reference was the same. Plus, I don't understand gating.
Do you mean listen to the difference between Variant R2 and Variant R7?
I exported the crossovers and EQ with the VituixCAD Impulse Response window. After you have all the variants (WAV files) in the Equalizer APO folder you can quickly switch between them in the config file. They all sound good to me. I prefer R7 because it sounds more accurate - to me - but I'll have people with better ears listen and compare.
I watched a movie called Chevalier (2022) last night on Variant R7. Left, Center, Right speakers but I have the DE250 on the center channel while using DE111s on the left and right. It sounds good. The DE250 had the inferior polar pattern due to diffraction off the large compression driver but I didn't notice. I wasn't as concerned with special effects as much as dialog intelligibility. The R-OSSEs have extremely good intelligibility. Dead easy to understand what the actors are saying.
I meant two versions of the waveguide, both with the same power response as you have now with your preferred version, but the second waveguide with flat on-axis response (i.e. more rising DI by that amount).
By setting different EQ you only change the overall tonality, but with those two versions you would change the tonality of the reflections against the direct sound - probably a lot more subtle effect, if at all noticeable (but maybe not). That would be the most interesting part.
By setting different EQ you only change the overall tonality, but with those two versions you would change the tonality of the reflections against the direct sound - probably a lot more subtle effect, if at all noticeable (but maybe not). That would be the most interesting part.
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