Amill trial was conducted at Norske Skog Boyer Mill, Tasmania, to test the hypothesis that acoustics can be used to segregate pulp logs into categories which will require different amounts of energy during mechanical pulping and will produce pulps with different strengths. 2247 Pinus radiata logs of varying age and length, SED, LED, taper, and volume were measured for acoustic velocity, segregated into four different velocity groups and chipped separately. Each chip group was pulped using the thermomechanical pulping process at Norske Skog Boyer using a range of energy inputs. It was shown that acoustics could segregate logs into groups that perform very differently in terms of pulp properties when refined to a given freeness or at a certain energy input.