pretty much same amp and 11band EQ ( analog as you astutely point out ) as the highly regarded model 7 less the push pull aluminum cone....so the guts and engineering are all there for sure....
as team swarm may mention two subs will to some degree help smooth things vs a single model 3, so it is somewhat of a tough call...what is your room like ?
I know Rhythmic have fans w good ears, I have an ESL63 project going where I may build a set of the dipole subs but rest assured IF I do they will need to be better than sub3....
on the integration question...Vandersteen known for seamless years of messsing w subs, most people have them turned up to loud...home theater style...just my $.02
as team swarm may mention two subs will to some degree help smooth things vs a single model 3, so it is somewhat of a tough call...what is your room like ?
I know Rhythmic have fans w good ears, I have an ESL63 project going where I may build a set of the dipole subs but rest assured IF I do they will need to be better than sub3....
on the integration question...Vandersteen known for seamless years of messsing w subs, most people have them turned up to loud...home theater style...just my $.02