The woofers have been refoamed. I suspect that's when the phase of the servo woofers was reversed.

any luck finding the servo control?

I might have a line on one through an AK'er.

I've picked up an IRS Epsilon servo unit and an Infinity Modulus subwoofer servo unit. I'm not using either of them as a servo control for the Delta's (yet) but I am using them as active crossovers.

The Epsilon servo unit (ESU) has a low-pass active crossover with bypass outputs for the top-end. The Modulus servo unit (MSU) has an active crossover for the high-pass output, and a DIN output to the powered subwoofer.

The configuration is IC's from the preamp to the input of the Epsilon servo unit, IC's from the ESU low-pass output to the PC5002M running the woofers, a 1/2 meter pair of IC's from the ESU bypass to the input of the MSU, and IC's from the high-pass output of the MSU to the MX-10000 running the top-end of the Delta's. Pretty simple huh!

I need to get some servo cables made. I ordered connectors, but when they arrived one type was wrong. I need to order a pair of 4 pin XLR's. Then I'll send the connectors to EW to make the cables.

The Delta's sound spectacular even without the servo control. The bass is outstanding, and the L-EMIM, EMIM, EMIT, and SEMIT transducers are simply beautiful sounding.