Factorio Forums

The sound of tier 2 and 3 machines seems to be muffled compared to tier 1 machine.
This is probably were done for reducing noise level, but it sounds odd (due to cut off high frequencies)
The old unfiltered sound was much better, although it might need a little lower volume (but maintaining frequency balance)

Thanks for the report.
I've asked our sound designer and at least for now there are no plans to tweak these sounds.