Hi, I own Sundara, Sennheiser HD600 and Beyer DT-880 headphones.
My prefered one is the Sundara, although I find the HD600 to have different qualities. The DT-880 is the one I like least.
It seems to me that the HD600 is more natural sounding with solo instruments and human voice. The Sundara sounds artificial and "hollow" in comparison. For example, in this track, the guitar sound like a real guitar with the HD600. Quite less with the Sundara :
Current 93 - A Beginning
On the other hand, I find the Sundara to be more balanced overall, while the HD600 sounds a bit harsh. I like the Sundara better for orchestral music. For example, in this track, the orchestra and choir sound great with the Sundara, while they sound a bit smaller and smashed onto my ears with the HD600 :
Bach Netherlands Society - Mass in B minor BWV 232
I have tried the equalization posted above (with REW / Foobar convolver) for the Sundara.
First, I don't like the bass boost at all. In this track, the lowest notes sound way too loud compared to the higher ones.
Unknown artist - Soeren
I find it much more balanced with a flat frequency response below 100 Hz.
Then I tried the rest of the correction without the bass boost. But I wasn't convinced. Yes, it removes the "hollow" sound of the Sundara, but on the other hand, it also reduces its ability to reproduce orchestral music .
Can we be sure that the correction is exactly what is needed ? The spike at 6300 Hz is very sharp, and any inaccuracy caused by driver to driver variation, or ear canal resonance would ruin the equalization.
Is the spike exactly at the same frequency when these headphones are measured by others ?
Also, it is very unlikely that this spike has exactly the shape of a parametric correction.