Prior to OTA updating my S9+ from O to P, sound output was beautiful from the time I purchased the phone last year. Specifically, low frequency bass was some of the best I'd ever heard. Unfortunately, after updating (about 3 weeks ago), looks like sub-bass is non-functional. I've noticed this on ALL bluetooth devices I've played it on (my car, 3-4 different current model headsets/earpods etc which all support BT 1.4).
I've tried the following, with no luck:
1) 10 band EQs. Mid bass and upper bass changes DO reflect in the output, but changing the sub-bass slider has zero effect. These same apps worked quite well when the phone was on Oreo.
2) Tried sub-bass apps that previously did a masterful job on Oreo, but literally zero effect. I could hear mid and upper bass being amplified, but the sound result is muffled garbage thanks to no sub-bass change.
3) Force stopped and disallowed system permissions for Samsung's Soundalive service, and then played with EQs and sub-bass booster apps again. No change.
4) Tried the above with all available bluetooth codecs in developer options (i.e. aptx etc). Same output quality
5) Played with the built-in eq and controls in Soundalive (i.e. enabling/disabling Atmos, adjusting the bass-boost dial in standard sound settings, and upping the bass frequency sliders in the advanced mode), and no difference whatsoever with low-end bass.
I haven't yet tried with a wired headset (mainly because I can't find the stock earbuds 
) , but I plan to as soon as I can find them.
There's been zero physical damage to the phone from the time I purchased it, just fyi, and as mentioned, the output difference was clear from the moment I updated to Pie. I also did a full factory reset a couple of days ago just in case any old apps were causing interference with DSP, and unfortunately the same result.
Has anyone else experienced the same after updating to Pie?
