Hi,
I was reluctant at first glance to have a look at the EQ as the data was near perfect. However after looking more closely it appeared to me the the integration of the mid range was, maybe, not that “perfect”.
I understand the compromise to get the third way: increase LF bandwidth and max SPL capabilities but it does not change the fact that the DI clearly shows the directivity errors.
It might be inconsequential in near field in a mixing studio where the direct sound might be paramount but in a domestic environment, where the domain of validity of Olive score is supposed to reside, it will decrease the Predicted Preference.
Here are some thoughts I shared:
https://www.audiosciencereview.com/...7v-spinorama-and-eq-inside.17283/#post-560611
[...]Regarding the scoring method itself, models in general, not just in audio, are judged with two main criteria:
- Can it describe what we observe reasonably well?
- Do the predictions derived from the model hold against new observations?
The first criterium is covered in the original paper:
https://www.researchgate.net/public...e_Ratings_of_Around-Ear_and_On-Ear_Headphones
I agree with you we need more data for the second criterium to be more understood.
We have some data point from the Harman team comparing different speakers with different PIR shapes and EQing targets but this not as detailed as the first paper.[...]
One may not agree (whatever that means) with the Score but this is the best we’ve got.
Nothing is preventing anyone from coming up with something different but the validation will be hard to say the least…
In the case of the KH310, the error from flatness are higher than one may think at first glance.
See the spinorama with just bass EQ (to look like the Neumann data):
View attachment 95191
Quick comparison with the KH80
View attachment 95215
NBDON = 0.34dB/20th octave on average
NBDPIR = 0.30dB/20th octave on average
SMPIR = 0.78 (closer to 1 is better, interpreted as smoothness of the PIR in the Olive paper)
Score: 6.35 / 7.76 with Sub
To be compared with the KH80 :
NBDON = 0.25dB/20th octave on average
NBDPIR = 0.22dB/20th octave on average
SMPIR = 0.86
Score: 6.04 / 8.4 with Sub
the higher score of the KH is due to the better LF response
The Score does not take into account the SPL headroom/THD.
View attachment 95214
The small one is just smoother and the sub score shows, in my opinion, that pound for pound and within its SPL capabilities, the smaller one is a better speaker.
Adding more ways on the speaker improve some parameters but also bring some other compromises, more is not always 100% better…
For the pound for pound see there:
https://www.audiosciencereview.com/forum/index.php?threads/jbl-308p-mkii-studio-monitor-review.17338/page-13
[...]Here is the calculation I perform, which seems to match what others are doing:
PPR_LF = 12.69 - 2.49*NBD_ON - 2.99*NBD_PIR - 4.31*log10(14.5) + 2.32*SM_PIR
see there for some details:
https://www.audiosciencereview.com/...urements-community-project.14929/#post-467858
This assumes:
- Frequency response 14.5Hz @-6dB. 14.5Hz is chosen so the theoretical max score is 10 although nothing prevent a system from achieving better performances and therefore the score could exceed 10; this is the first issue.
- Perfect integration whatever that might mean, which is the second issue and where I don't quite adhere to the concept.
The idea, I guess, is to compare speakers if the LF extension is literally taken out of the equation, akin the pound-for-pound rating.
To me it would make more sense to use it this way rather than thinking "if I buy a sub then I'll get the astonishing system predicted by the sub score". That is just not going to happen: sub or not the room will still determine the system LF response.[...]
Here is my take on the EQ nonetheless:
I think unless the user has a decent understanding on measurements and their interpretation it is probably better not to play with the EQ or just FYI. The final user should measure his/her own units, at least the LW.
Room integration EQ is highly recommended thought.
The raw data with corrected ER and PIR:
Score no EQ: 6.19
With Sub: 7.6
Spinorama with no EQ:
- LF response, is it temperature related or otherwise? I EQed it so that it to resemble the data published by Neumann to get it out of the way.
- HF it seems that there are tonal control that do pretty much the same job that the EQ I added…
- The midrange integration maybe related to production tolerance?
View attachment 95204
Directivity:
Better stay at tweeter within +/-10 deg of the mid point Tweeter/mid both vertically and horizontally.
View attachment 95208
View attachment 95193
EQ design:
I have generated two EQs. The APO config files are attached.
- The first one, labelled, LW is targeted at making the LW flat
- The second, labelled Score, starts with the first one and adds the score as an optimization variable.
- The EQs are designed in the context of regular stereo use i.e. domestic environment, no warranty is provided for a near field use in a studio environment although the LW might be better suited for this purpose
Score EQ LW: 6.82
with sub: 8.22
Score EQ Score: 6.98
with sub: 8.39
Code:
Code:
Neumann KH310 APO EQ LW 96000Hz
November232020-121217
Preamp: -2.3 dB
Filter 1: ON HPQ Fc 29.1 Hz Gain 0 dB Q 0.9
Filter 2: ON PK Fc 89 Hz Gain 1.63 dB Q 2.21
Filter 3: ON PK Fc 707 Hz Gain 1.18 dB Q 4.87
Filter 4: ON PK Fc 1548 Hz Gain 2.32 dB Q 6.71
Filter 5: ON PK Fc 4779 Hz Gain -0.88 dB Q 8.74
Neumann KH310 APO EQ Score 96000Hz
November232020-110222
Preamp: -2.3 dB
Filter 1: ON HPQ Fc 29.4 Hz Gain 0 dB Q 0.9
Filter 2: ON PK Fc 88.4 Hz Gain 1.63 dB Q 2.21
Filter 3: ON PK Fc 700.8 Hz Gain 1.06 dB Q 4.56
Filter 4: ON PK Fc 1525 Hz Gain 2.25 dB Q 10
Filter 5: ON PK Fc 4714 Hz Gain -1.31 dB Q 5.85
Filter 6: ON PK Fc 12878 Hz Gain -0.69 dB Q 1.04
View attachment 95203
Spinorama EQ LW
View attachment 95205
Spinorama EQ Score
View attachment 95206
Zoom PIR-LW-ON
View attachment 95207
Regression - Tonal the EQ score makes the On flat
View attachment 95200
Radar no EQ vs EQ score
Some improvements
View attachment 95201
The rest of the plots are attached in particular Horizontal directivity with positive and negative angles separated.
View attachment 95195