i have experience with the ATC SCM-50A, SCM-12, SCM-7, and SCM-10A and both of the ATC preamps.
firstly, the ATC speakers all sound nearly identical, the only real differences are in bass extension. the 20s use the same driver as the 50s, which is, IMO, the greatest mid-range driver ever. if you get these speakers, look into the tweeter upgrade (if they don't have the new tweeter). i've not yet heard the new tweeter, but all accounts say it is far superior to the older one, which some viewed as the only nit-pickable flaw to them.
as far as the preamps go, neither impart *any* sonic signature to the sound at all - they are stunningly transparent. my brother uses the smaller one for his 50s and i use the larger one for mine. we've done comparisons before and the difference is in detail. the larger one simply allows more music to come through, but the smaller one is exceptional at the price.
for the size of your room, the 20s are likely an excellent choice. please feel free to ask any other questions you may have.
firstly, the ATC speakers all sound nearly identical, the only real differences are in bass extension. the 20s use the same driver as the 50s, which is, IMO, the greatest mid-range driver ever. if you get these speakers, look into the tweeter upgrade (if they don't have the new tweeter). i've not yet heard the new tweeter, but all accounts say it is far superior to the older one, which some viewed as the only nit-pickable flaw to them.
as far as the preamps go, neither impart *any* sonic signature to the sound at all - they are stunningly transparent. my brother uses the smaller one for his 50s and i use the larger one for mine. we've done comparisons before and the difference is in detail. the larger one simply allows more music to come through, but the smaller one is exceptional at the price.
for the size of your room, the 20s are likely an excellent choice. please feel free to ask any other questions you may have.