I had exactly the same feelings when I listened to them from the box for the first time. The only thing that immediately struck me was the vocals. But then the bass and the high frequencies appeared with a burn. But do not expect bass at Sony's XBA Z5 level. "BOOM BOOM BOOM" - this is not here.
As we see on the chart the bass and high frequencies are on the decline. But the mids are outstanding (especially the vocal area - 2-3 kHz.) You have to pay for everything. The great mids demands sacrifice.
crinacle made measurements of the LAB 2. Although I did not have the opportunity to listen LAB 2, but from the measurements I see that they are significantly different from the PF series. The vocal area of LAB 2 is reduced (2-3 kHz), their graph is more like the reference monitor sound of the Etymotic ER-4s. The bass line became more even,but for such a smooth bass FINAL AUDIO had to reduce the vocal area. For me as a vocalhead, I'm sure Piano Forte 10 will be higher than LAB 2. Probably PF10 is the best headphones in the world for vocals.
To my taste, nevertheless, PF 8 is much inferior to 9 and 10. If there is a possibility it is better to immediately skip the PF 8 and buy 9.
the piano forte 10 is indeed the king of voices vs the lab 2, even in this small part of the fq range the resolution is a tad better (realy outstanding). the magic of the piano forte 10 is the focus on the mids, missing/or reduced parts of the bass and the highs gets you a extreme sharp focus on this part of the music. the piano forte 10 has a magic with voices that is unique