Informal Listening Tests
Listening tests as before were with JBL LSR305P on my left as the anchor/reference and the Neumann KH 80 DSP Monitor on the right. Levels were matched using pink noise.
The first noticeable thing was that the KH 80 was most similar to LSR305P than any other speaker I have tested so far (which is not a lot). With other speakers you would immediately hear strong accentuation or lack of energy with the differential being quite large relative to the JBL. Here, all the spectrum was here.
I was then surprised that I did not prefer the KH 80 considering that it has even smoother response than the LSR305P. There were two issues here:
1. The scale was too small. This may be a visual bias but the KH 80 sounded more like a little computer speaker than a large speaker that the 305P sounds like. It was a more focused sound emanating from a smaller source. This was a much smaller issue than #2 though.
2. The JBL had a bit more "zing" and clarity as a result that was just lacking in KH 80. Focusing on the graphs, I noticed that the 305P has good bit of peaking (relatively speaking) in and around the frequencies that the KH 80 is weak in. Since I was doing my listening tests using Adobe Audition, I pulled up its parametric EQ and dialed up the 1.8 khz area by about 3 dB. That made a big difference and brought the response and signature much closer to that of JBL. The good directivity meant that there was no ill effect to such a boost.
I figured if this worked, I would bring up the bass a bit to better match that of 305P. Big mistake. Sound went to hell and fast. This thing is optimized for what it already can there.
I am super anxious to see what the Olive preference score says about KH 80 versus the JBL 305P. If it ranks the KH 80 higher then we have some work to do to rationalize my informal listening tests. If so, then I need to expand my listening tests to be more formal and in better environment than just my desk.
Conclusions
The Neumann KH 80 DSP Monitor measures quite well and seems to be competently designed.. This may make it a very good fit for pro use in recording and mixing. For hifi listening though as I noted, I still prefer the JBL LSR305P. The JBL projects a larger image, has more bass performance and detail in mid-range. It is also cheaper. So personally I would not use the KH 80 DSP but you have the data to decide for yourself.
Net, net, we have some work to do to better objectively qualify performance of speakers like Neumann KH 80.
Yes subjective listening tests are not very meaningful when simply putting the speakers on a desk in a normal room.
There are so many variables.
First of all, the standard is setting up speakers on an equilateral triangle. This matters a great deal as your HRTF differs a LOT when angling speakers wider or narrower.
Secondly, placing the speakers on stands and without a desk or other reflective surfaces, just free space. Equal height for all speakers tested. And I believe there's some ISO standard that says speakers should be more than a meter away from any walls (though if less than a few meters this will still give you a reflection cancellation dip in the bass).
Thirdly, a big room that is well treated. Studio standards. Treated first reflection points, smooth even response / RT60.
Then, when reverb and reflections are low enough you'll find that all of a sudden speaker distortion matters a LOT and becomes very audible and find those LSR305p are big distortion boxes amongst other things
Should such listening conditions materialize I can suggest using a standard EQ for the bass equally applied to all speakers to correct for the specific room and placement.
Btw, a subjective test of many nearfield studio speakers was done in a similar way in this thread:
https://www.gearslutz.com/board/high-end/851143-high-end-nearfield-test.html
It's 116 pages long and one doesn't learn much from it so not recommended reading