Does the sound from your Behringer speaker change character (become thin) after it's been on for an hour in Delhi? This points to a component whose value drifts with heat, like a thermal runaway transistor or a heat-sensitive capacitor. Solution Hub Tech can perform a thermal diagnostics test to find the thermally unstable component and replace it with a stable, temperature-compensate... https://solutionhubtech.com/behringer-speaker-repair-in-delhi.html