I am not using symmetry optimization so it is measuring all around. Left to right symmetry is good with the KH80 so I could have done that:
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Then again given the food fights we are having over small variations, it is better that I am not.
Haha I think you will find most of us have no trouble with symmetric measurements on symmetric speakers! The time savings are definitely worth it if you're running low on time or if you plan on measuring multiple speakers. It's pretty standard procedure.
I doubt anyone would complain if you chose to do this going forward or in specific cases where it would save you time.
I think most of the food fighting has been over what aspects of sound we would expect to be consistent between measurement setups(i.e. low q deviations). But we mostly know the reasons now - the klippel is a new system so we're learning as we go. In some ways it's very different than traditional measurements, so we have to adjust our expectations. This isn't to say that's a bad thing, we're just learning.
Wouldn't have objected at all to speakers with a symmetrical design.
You act as if some users here in the forum are splitting hairs over every detail
It would halve the time needed for the measuring process.
Note, however, that the two dotted grey lines are only 1.2dB apart.
So the dip you marked should be in the range of 0.2dB.
As I think you mentioned or someone else mentioned before there was less compression on this sample than the previous Neumann sample due to the SPL level? This would be something a compression test could quickly put to rest, which I think Amir said he was working on.
That said, assuming the overall level was not too loud(do we know the actual SPL
@amirm?) I'm inclined to agree with the NFS. Nearfield bass summation, which both S&R and I use, is always a bit of a guessing game. On the KH80, it's a also bit harder than usual because the fixed grille doesn't let you get as close to the woofer as you should. I'm not at my REW computer, but between placing the microphones at the right distance (which, again, you can't really do on the KH80 because of the fixed grilles), summing the port and wooofers correctly(which is also more difficult because of the fixed grille, plus picking the exact right effective piston diameter), picking the right splice point, and properly modelling baffle loss, I always assume some deviations in nearfield summations. Well-done ground plane measurements might be better in this regard though they tend to be noisier.
I previously used this comparison to show the consistency in my HF measurements of the Neumann (using two different microphones, speakers, and setups), but it can also be used to show the (slight) inconsistency in my nearfield bass summations.
A slightly bigger difference is in the on-axis measurement in this image, where I'd picked a different splice point when it was made:
Obviously small differences, but just an example of potential deviations in nearfield summations even when done by the same person. It's also worth noting I did these summations after seeing Neumann's data. While that shouldn't affect them in terms of procedure, it did mean I automatically assumed the data was correct because it closely tracks neumanns. WhatBias always finds a way
On the other hand, to the point about smoothing, I do not think S&R is using very much at all. My measurements above are 1/24 octave smoothed and are not averaged except for the listening window. Even taking into account the reduced resolution of gated measurements, above 3K or so the klippel and my DIY measurements should have similar resolution after smoothing. the HF deviations are smaller than those captured by the klippel, despite being recorded in a living room and my graph using a taller aspect ratio than Amir's(relative to dB).
So here I assume either:
-The bumps are caused by reflections in the setup ( I take extra care to avoid these by using a long boom angled such that the mic doesn't "see" it's stand)
-The klippel is somehow capturing something about HF soundfield not captured by a single mic.
To be clear these bumps do not personally concern me much though other than as an academic curiosity. I was more concerned with low-q deviations which we now mostly have the answers for.