Check Spotify settings and put it on the maximum quality they have for streaming and downloads. Not much else you can do past that. I use Spotify mostly for pop music I can't blow money on buying the CDs or FLAC copies (since I already blow enough money on metal CDs).
Maybe install a global EQ app like Equalizer APO on Windows or Neutralizer on Android. Just note that EQ APO is more of a pro tool where you have to put in the adjustments based on educated guesses from at least one or two different measurements of your headphones and trim the peaks, while Neutralizer runs a test tone and then you adjust the gain on each frequency (they affect a wider range than just that center freq). Similar bit - just trim the peaks first, but for Neutralizer since your own hearing is involved, don't cut too much at 1000hz and 2000hz to match everything else since human hearing has a bias in those frequencies, not to mention sensitivity measurements are at 1000hz. If it's painfully loud on the test tone at those frequencies, trim a little then boost the other freqs.
Hi there, sorry for bringing up an older thread but this might still interest someone.
I'm on LG V30 with Oreo, this phone has two DAC chips (one regular Qualcomm and one audiophile quality quad-core ESS Sabre) and an integrated hifi amp.
I've have tried it with Tidal app and don't seem to have an effect on tonality but it did something to the gain as it lowered the volume a bit.
Streaming Tidal through UAPP Tidal plugin (so not through the native app) - it doesn't do anything at all, zero effect (playing Tidal through UAPP is the preferred method as it brings a number of improvements related to the hifi DAC and bit perfect operation but this method uses a third party audio driver and not the native Android one).
On the other hand, Neutralizer works as intended with Youtube.
Maybe the presence of two DACs is making Neutralizer having a hard time in this case.
Cheers.