Problems in push-pull biasing
Emitter resistors on the darlingtons do help "soften" the biasing problem. One ohm is too much as you have found - they consume too much of your available power.

Biasing those darlingtons into Class AB is tricky. Even if you could find a 2.8 volt battery to replace your series diode string, the darlingtons are at risk of thermal runaway.
Q3 (below) along with D1, D2 and variable resistor R3 form an almost-constant voltage source of about 2.8V. You can vary its voltage with the variable resistor.
To counteract the thermal runaway problem, Q3 can be thermally tied to the heat sink where Q1, Q2 sit.







simulate this circuit &ndash; Schematic created using CircuitLab