Relieve yourself of a little clamp and slide the earcups down a bit more. I am also going to be a bit more curious as the gap between the Sine and PM-3 widens more than your initial impressions.
Thanks for the helpful slider suggestion and encouragement.
So for $500+ and portable, I want MAGIC.
Three days non-stop PM-3 (now minus Dragonfly Red- too frankensteinish) vs Sine + Cipher vs Sol Republic BT Air Tracks; now feeding all of them Tidal "hi-fi" $20 level (free trial 30 days) I think Sine is starting to show me the magic.
I fed all three headphones same playlist today; Santana "Maria Maria" and "Smooth"; assorted Patsy Cline original Decca Master tracks; Pink Floyd "Comfortably Numb" and "Breathe"; Peter Gabriel 1988 human rights concert live version of "Biko", "Sledgehammer" and "In Your Eyes";! Sade "Your Love is King" (for the sax solo) the entire Carol King Tapestry album - on all three. Sol Republic BT Tracks Air, Oppo PM3, and Sine. The SRs have north of 100 hours.
There's no way to talk about so much music. Carol King can play the crap out of the piano; and her string/vocal/percussion/keyboard arrangements are why we all know those songs by heart. I've listened to it hundreds of times. Ditto the others selections . We all know "you've got a friend" and I'm not going to say what happened when I listened to that on Sine except it was a moment. What I heard was Sine is able to separate King's left hand piano and right hand piano to left and right ear cups, perfectly. The other two can't do that nearly as well. Her "Smackwater Jack" and Gabriel's "in your eyes" on Sine made me air guitar the bass and air-bongo, respectively, and I can't really play instruments. Frankly, I've never air - bongo 'd before. The crescendo of "in your eyes", cymbals crashing, frenzied percussive arrangement I couldn't sit still with Sine. Peter Gabriel and Youssou N'Doir 's soaring surreal vocals gave chills. The hypnotic, synthesized bag pipes in Biko, the audience cheering and singing along, my eyes closed I was there. And this is a live recording - so hard to reproduce well. Again, my home rig is Yamaha and klipsch reference and I like the klipsch "wall of sound" sound. Sine is a similar wall of sound.
So far the other two headphones don't really come as close to fully engaging as described above. .
With more time on PM3, what I can say is without separate DAC, it's underpowered with a phone. PM3 are still way, way more comfy but the sound quality is not as engaging without a DAC. I think these may be third place now being strict on "portable".
Believe it or not, I'd give second place now to the Sol Republics if we stick to "portable" criteria. The SRs, with Tidal, are fun, light, fast, and I wish I bought two during the $38 groupon sale. Perky, bright, and flawless iOS control. If you're looking for on ear BTs, and you find these for less than $50 I'd grab one. Didn't think they'd be as good.
Okay....not done yet. Now I have to still try both PM3 and Sine with my reference yammie AVR as source. I have a hunch the PM3s might fare better there.