UREI 813 crossover rebuild

[kwingylee]

Guys
I finally got around to semi-restoring my UREI 813s (serial numbers 101 and 119) with the Altec 604-8G drivers. In the process of recapping the crossovers, I noticed a discrepancy between the "original" crossovers as I purchased them and the schematics that I pulled off the 813 owners manual in the JBL PRO website. The schematics showed a 10uF capacitor C8 in series with a 50 ohm resistor R1 interconnecting the 604 LF driver and the Eminence LF woofer. In the crossovers that I have, there is no 10uF capacitor and the 50 ohm resistor is connected across the terminals of the Eminence woofer. Does anyone on this forum know the purpose of C8/R1 as they are shown in the schematics. Looks like a low frequency signal is capacitively coupled into the Altec woofer to improve the bass response perhaps? Appreciate any analysis on this. I am not sure about any audible benefits.

Another issue is the UREI blue horn mounted to the 604-8G. All of the foam has disappeared and I want to replace them. Does anyone know a good source for the foam?

All signal paths to the Eminence, 604 LP and 604 HP drivers go through 3 different sets of light bulbs. I plan to by pass all of the bulbs. I cant imagine this being good for the sound. Any opinions?

Other than these issues. I am pretty close to being done. I recapped the crossovers using Soniccap, Jensen, Jantzen Z series, crosscap and AXON film caps (there are a lot of caps). I left all of the aircore inductors (5) in place. Cant wait to fire these up hopefully in the next couple of weeks.

Kwing