Hi Ivica,
Wow, 5 dB less on Beyma. It also has a "bump" in response between 7 and 10 kHz. That could produce a lot of sibilance i think. At the end a lot better than my 075 with those wrong diaphragms.
And, speaking of diaphragms...
I have dismantle my 075.
At the end I don`t know what they should be, but I have noticed that central ring do not lay firmly on the pole piece. I have remembered Simply speakers video about installing 077 diaphragms in to 075 and I went through this topic;
http://www.audioheritage.org/vbullet...or+comparisons
So I made 0,19 mm thick rings to put below diaphragm central ring. That made difference. And I have measured;
But, when I have install tweeters in the system, although, they performed closer to what they should, they had a lot of sibilance. And I mean a lot. Sssss`s were cutting ears. Measured system;
It was obvious that around 7 KHz and past 10 kHz there are big resonant or distortion or breakup peaks. I managed to tame those peaks by apply heavy eq on dsp. That tamed peaks but bring another set of problems, sound is not right...
I have also found those diaphragms, they should be original;
https://www.simplyspeakers.com/jbl-r...gm-d8r075.html
What do you think?