I have both the new XM3 and the first model MDR-1000X.
I find that the latest model has really too much bass. Really, really too much.
If you listen to something acoustic, like a piano or a guitar, the sound is not very natural.
In comparison, the MDR-1000X has a more natural and balanced sound.
However I have to say that the new model XM3 gives no listening fatigue at all and invites you to always increase the volume. Even with poor recordings, the sound is never too harsh while with the MDR-1000X you really had to decrease the volume.
The XM3 sound can be equalized with the Sony's app but, if you enable the equalizer, the Bluetooth connection automatically switches back to SBC codec (low quality codec).
It is very disappointing that you cannot use the equalizer with the high quality LDAC Bluetooth codec.
I hope that Sony will solve this very bad issue soon.
As an audiophile, I do feel uncomfortable with equalizers. My philosophy is that the headphones should sound right just out of the box. Can anyone suggest a good third-party equalizer? I mean, an EQ app that works well and does not degrade the sound quality too much.
Maybe What Hi-Fi should write a review about EQ apps. It would be very interesting.
Overall, I am not very satisfied with my purchase.