Go to PS4 audio options in the settings and change the output to DTS (it's probably linear by default). This will give you bass and slightly better Spotify sound quality, it's what I use now. It's not great but it's at least passable. Barely.
There is a very real problem. I have been using Spotify premium since 2009. I upgraded my system last fall, and in the process changed the source from Apple TV to PS4. Ever since I haven't been happy with the system, and first I thought my new amp is not powerful enough for my new speakers. We finally identified the source of the problem, when we started renting movies via the PS4 amazon app. The movies have hugely better audio than Spotify. There is no question about it. Moreover, this cannot be about the hardware set-up since the hardware is the same: Spotify vs amazon PS4 app. The problem is so apparent that nowadays also my wife rather uses YouTube for streaming music than Spotify. If there is no fix in the near future, I think I am going to get Bluesound and change for Tidal.
I'd just like to add a "me too" to this. The sound is so bad that it's not worth listening to the free version let alone paying for premium. Like others i get great sound from other sources and apps. Please fix this spotify/sony, I've just bought a new phone and amp and this feature was one of the key reasons.
Ah yes, the PS4 Spotify audio issue. Still going strong. I just got done with a 6 month Tidal trial. Say what you want about Tidal, but the HiFi/Master option is just terrific. With that said, still can't justify 20 bucks a month for it. So I let the trial end, and pick up Spotify again.
The flaws the the PS4 are even more apparent. The tiny highs, the muddled lows. Somebody said above that Chromecasting is better, I concur. I get even better sound quality using my PC set up.
This isue is going on over 2 years now I think, i do not think Sony or Spotify are putting time into fixing this.
I have a pioneer VSX-822 running to technic towers. Playing Spotify through AirPlay on the receiver sounds as good as streaming compressed files is going to sound. Since I have everything running though my reciever, if I want to do anything other than listen to audio, like play on my PS4, I have to switch from AirPlay input. So to listen to Spotify I have to play though PS4 and it sounds like it's been compressed 100 times more. It's terrible. There's absolutely no low pass frequencies. I've tried both the different output settings on the ps4 and the format settings, it makes little to no difference in Spotify. No other audio coming from the ps4 sounds as terrible as Spotify. It would be nice to be able to access the EQ on the Spotify app but you can't do that while connected to a device.
Please fux with this. It really shouldn't be that hard to find the problem and have PS send a patch.