The phrase "banging out" typically means to produce or create something quickly and efficiently, often with force or energy. Antonyms for this phrase might include "sluggish," "lethargic," or "uninspired," as these words suggest a lack of energy or motivation. Another possible antonym could be "deliberate," which implies a slower, more intentional approach to a task. "Faltering" or "stumbling" could also be seen as antonyms, as these words suggest a lack of confidence or proficiency. Ultimately, the antonym for "banging out" depends on the context and tone of the situation.