Goatwuss is dead-on. The C1's with a Sub500 will not better the C4's overall for all the reasons stated.
However, I've owned the C1's with dual Sub500's and I loved the combination together. The Dynaudio subs don't get the praise that they deserve, they are wonderful and mate extremely well with the C1's.
However, I've owned the C1's with dual Sub500's and I loved the combination together. The Dynaudio subs don't get the praise that they deserve, they are wonderful and mate extremely well with the C1's.