Tomorrow I’ll be firing up my media room for the first time
and then it will be time to start tweaking/calibrating/putty adjusting/measuring/tuning.. So my question is if I’m going to cross everything over to a sub at 50/60 Hz, is it worthwhile to do the whole putty adjustment thing or should I leave the speakers over-damped and match the sub to the speakers? Seems like a waste to dial in the bass then cut it with a x-over, unless harmonics audibly reach into the midrange. The speakers in question are RM30, RM2, LRC and IB sub.
Yes, it is always best to adjust the putty and the pots.
Actually since you will be rolling the RM30s off a little early, removing more putty can make them a little faster. Very simply what your doing is reducing the "mass" (weight) of the passive radiator cones, which respond to the air pressure within the cabinet at the lowest resonance.
If they are too heavy, they will respond too slow in reacting to the pressure. If they are too light, then they may "over respond" or slightly over shoot their excursion.
This would cause them to sound a bit bloated or wooly.
So simply take about a large pea sized amount off "each" PR.
Then twist the pots (L-pads) up to around 12:00 or so, and let the speakers break in. They may sound a little edgy or tight for a short while, then they will smooth out and as they reach "sonic puberty" they will get a bit more throaty and their voices will get deeper.
(If they begin to grow hair, you've gone too far

)
After 30-60 days (depending on how much and how loud you play them) they will reach sonic maturity, and should sound incredible.