Let me start by saying that I have a new found hope for music with home audio! This is my first experience with separate amplification for HT.... I am a big car audio guy (Alpine HU, Polk speakers, Kicker Sub with dual Kicker amps), so it would honestly be tough for me to say that I've never heard audio how it is supposed to sound. The car has always been my "music testing ground" (confined spaces definitely have their advantages) for what music should sound like.
Having said that, I have never heard that clarity, that definition, in the home setting until tonight. And it's better!! The RTi12's finally "woke up". They sounded great before, but they have reached a whole new level. The best way to explain the difference is that they sounded totally unrestrained. Powering them with my Onkyo sounded good, but with the Parasound they are crisper, clearer and just sound more natural. I can finally play them as loud as I can stand and get no distortion or feeling that they are being pushed too hard.... it seems their limit is as loud as my ears can stand :) and crystal clear! The sound fills the room (very large open room w/ high ceilings) with ease. The sound isn't coming from 2 speakers, it just surrounds you.
I decided to test the speakers with the new amp without my dual subs. I have always been a fan of subs in both car and home audio b/c they just provide that lower end "thump" that is so awesome. While I will say that the subs aren't going anywhere for HT, I honestly never once felt the need to hook them back up for music. Every time I thought I would need subs, I was proven wrong by the speakers own performance. If you think you "need" a sub with the RTi12's, you just aren't giving them enough power... seriously. I was blown away with every type of music I tried! I will keep my subs but only because the more power the better in my eyes... they are set now to play only the deepest bass as to not strain my speakers more than need be.
For anyone debating a separate amp... don't hesitate. WOW, what a difference!