Map, the radial driver for the ERR's is a modified cast chassis 8" driver. From what I can tell it is reworked with the cone-which is very lightweight-and inverted, and attached to the spider/voice-coil by a spacer for lack of better terms. I know this isn't much detail, but the whole assembly is very well put together and well thought out.
The cabinet is not ported, but a passive radiator/drone cone is in the bottom of the cabinet, and there is a plinth that has a separation between the cabinet and the plinth for the bass.
I have talked to Zygi about the ERR's, the guy that builds these for Decware. Very nice guy, he does wonderful cabinets/veneering. I have been considering trying a pair of these for awhile now, I have been very curious about the overall sound in comparison to Ohm's.
I do like the idea of the ribbon tweeter and ability to adjust or tailor the sonics via capacitor/resistor choices if so desired. Don't know how mcuh difference can be detected, but at least it is user friendly in that regard. Tweaker's delight if so desired!
There are a few things that make me curious about these, one is the rated frequency response, seems to go fairly low for a cabinet that is more inline with the Ohm Walsh 2, and also pretty high sensitivity made for tube amps mainly. Also again, the fit and finish of the cabinets, hardware, grills kind of top the whole thing off for me. Of course the music they make has to be in line with the rest of the goods, so we shall see! Maybe later on this summer. Tim