intresting how the small thing can match distorsion of the Neumann until 200Hz
Yes, but, at higher SPL there's more distortion from the single driver. At moderate nearfield volumes both perform well.
With regards to the difference in wall reflection, I was either standing or sitting beside the mic while controlling the mouse, so could've been my body changing the pattern. Just disregard that.
Oh, and I absolutely did not apply any EQ to the two monitors myself, even with the sub added they ran full-range "as-is". The difference in GD is caused by the mid-to-high frequency driver analog crossover present in the Neumann -- which is very simple to post-correct with DSP to make it more "flat" --
horizontally, mostly. The weirdness in the Fostex above 10kHz is likely from baffle edge diffraction and/or reflections -- desk measurement was off-axis so this exaggerated things a bit. If you look at the Neumann's baffle design, even the mid-woofer part is very precisely shaped via computer modelling to make the transition as smooth as possible.
Axial trace in white exhibits less peaking in the GD above 10 kHz.
the left one in the "presence" range in not so drastic and an easy EQ,
in the right "brilliance" one is strong and shows severe conacelations.
I think it is caused by the case and I wouldn't be present if toed-in to the neo-standard on-axis (note the dip the 30-degrees takes in the same range):
Listening on-axis gives you more HF, but it is still lacks that magical sparkle or alternatively, let's say, "metallic clang" I would expect from certain brass or percussive instruments. The HF sounds much louder, sure, yet still somewhat muted, damped, or subdued in comparison. EQ may be possible to improve things a little, but there's the possibility it would introduce some unwanted harshness; even more likely, distortion will rise earlier there when increasing the volume.
about the off-axis meassurements: there is an increasing dip caused by a resonance (wall mode?). here on the 90 degrees:
Unfortunately, the measurements are not as pristine as I would like since this was measured indoors (consider all the boundaries) and I did not move much furniture out of the way -- so can't totally be sure the cause of every single difference, to be honest -- but an obvious guess would be off-axis driver beamwidth significantly narrows particularly at that point adjunct to diffraction. Now, at 90 degrees, driver is pointing up the ceiling... which is about 7 feet high with the single driver about at midpoint height perhaps (not exact estimate). If the monitor were shaped round like an egg we might not see such a severe dip.
btw: when you have the oportunity (while meassureing another thing), could you just add a single mid and/or far field meassurement? in another thread there was a theory that HF would decay rapidly with distance.
A theory ... supported by a body of evidence. I've actually made measurements at different distances and the theory holds true. I'll post one of the KH120 I already have done at less than a meter and one at more than two meters shortly.
I am so happy to see these meassurements. thank you a lot, man. even though not anechoic, they show enough to have a good idea, even more so compared to a great monitor the Neuman is. I spent the whole morning studying them.
Very much welcome and appreciate that you found these useful.
hard to remove the grill?
Don't remember if the grill was removable, however, it was already completely flush with the rest of the aluminum cabinet so it likely would not have made a big difference even if it did contribute a little bit to some of the visible FR unevenness/irregularity.
As to why I found myself listening to the Fostex more with the sub, well listeners generally like more (good) bass extension. The HF still sounded very good and was audible when listening to music. For now, let's just say HF "sparkle" or brilliance isn't number one in my list of priorities. Bass is far more important.
Lastly, with the importance of left-to-right measurements... even though we have a single driver, the cabinet geometry contributes to the sound and is different depending on which off-axis angle your ears/head are positioned at relative the monitor orientation.