If you look around the forum, you can find a variety of different opinions on the streaming quality of Quattro’s on treble vs. bass, etc. For example, this main thread on the Quattro’s:
Having a car with a great sound system where the subwoofer can make stuff on my body vibrate if I foolishly crank up the volume, I’ll have to say, YES!, by comparison, my Quattro’s really lack bass output. Most Phonak Marvel users seem to think those HA’s have stupendous bass output - but I’ve read a post where someone claimed that treble was sacrificed in comparison(?). I wear pretty occlusive molds so theoretically when streaming I’m getting a few tens of dB of bass boost by not letting low frequencies escape my ear canals. The bass is still not as good as my car audio or even the bass obtained when wearing my Surface Headphones over my HA’s (the added bass from those blasts its way through my molds - with the Surface Headphones, I can get some “sound” from a tone generator app on my smartphone down at about 20 or 30 Hz, even below the official low-frequency cut-off spec of the headphone!).
I’m not an audiophile and probably don’t appreciate if I’m really missing anything. But I’d say with occlusive earmolds (worn for other reasons) that I have pretty good bass with my Quattro’s. I mostly listen to talk podcasts while streaming and I think the overall quality and tone balance of those is pretty good, especially with my earmolds.