Sushii- Is there a level control for the tweeter there? Usually, on those old EV drivers there is a provision for tweeter level adjustment, which should allow turning down the high end a bit. If there's nothing obvious, you can probably get to the tweeter connections inside the unit- if you unbolt that metal cap on the back of the magnet (there should be a screw in the center, under the foil label), you should be able to see some terminals in there, where the tweeter connects. You can connect in an L-pad there, and control the tweeter level...
Mike- yeah, that definitely looks like a Jensen to me. That magnet "bell" cover and that basket, it's pretty unmistakable.
Regards,
Gordon.