The very best solution to increase the sound quality of your Nothing Phone 1 speakers tenfold.
Download the App Wavelet on Playstore. Wavelet is free and pretty smart.
It knows what device you currently use and switches profiles accordingly.
https://play.google.com/store/search?q=wavelet&c=appsEnable compatibility mode in Wavelet settings and apply the following values that you can see in the Screenshot.