Lower the node's threshold until the gain reduction meter starts moving only on the loudest notes . If the reduction meter is constantly active, your threshold is too low. Raise it until only the "booms" trigger it.
QREC removes gain . This preserves the natural timbre of the source while preventing harshness from poking through. waves qrec manual
Double-click on the peak at 78Hz. A node appears. Lower the node's threshold until the gain reduction