I have the 1025X of the BB Yamaha series that this technique addresses (BB2025X). I'm waiting for the 2025 (used) to arrive hopefully this week. I can rent it and compare it directly to the 1025 that doesn't have these treatments. Should be interesting. From Yamaha:
ARE (Acoustic Resonance Enhancement)
This environmentally-friendly non-chemical technique transforms the wood to give a superb sound. Using precise control of temperature, humidity, and pressure, this technology alters the structure of the Yamaha bass' wood at a sub-cellular level, transforming it into the same material as would be founds on an instrument that's been played for many years, into a material that resonates beautifully. ARE technology brings this 5-string bass guitar to life, sounding great from the moment you pick it up.
IRA (Initial Response Acceleration)
IRA is a special process that involves resonating the guitar at a certain frequency when it's finished being built, and it's strung and tuned. It actually has the same physical effect as years of gigging, playing. This corresponds to greater sustain, better high frequency response and, overall, just a more lively, open sound.
Both IRA and ARE technologies are applied to the Yamaha BB2025X bass guitar. With this chemical-free treatment, the bass sounds silky smooth and mature right out of a factory.