I used to have the EBS. Delightful, with ATC drivers
It's 18in H x 8w x 13 in deep with the grill attached
The woofer is 6.5 in including the surround, The port is the "packed drinking straws" type
Might be Studio 2's?
What model ProAc is this
I purchased them used from the Stereo Exchange, NYC ~1985. (They still sound excellent, btw)