I haven't heard any of the Song 3 models, the Encore looks interesting. I have had the HT2-TLs for 10 years and love the clarity, they seem true to the source. The HT2-TL speakers work best with high powered traditional Class AB amps like Van Alstine. I listened to Class D loaners for weeks and they are not a good match.
One of the best upgrades I made was to get a REL subwoofer. The HT2-TLs are so good that it requires an excellent, fast sub which means one of the expensive RELs. Why?
Because the HT2-TL go down to 34 Hz. My REL Gibraltar low-pass is set at 30 Hz. If you haven't heard bass into the teens then your are missing the music's fundamentals. And it's not about bass, it's about the room. Almost everyone gets this wrong because they have subs that don't do sub frequencies.
Watch an explanation by John Hunter, CEO and Chief Designer at REL Acoustics:
https://www.youtube.com/watch?v=pSHkpy2280QThe Salk 3 Encore bass goes lower that the HT2-TL, 25 HZ or lower with room reinforcement. But then you can get into placement problems. A sub can be placed anywhere. Perfect imaging may not be the best location for perfect bass with a all-in-one speaker. The room is just as important as the speaker.
Without a room size and electronics and photos it is almost impossible to make a suggestion.