After purchasing some vintage L300’s I discovered the tweeter on the "right" speaker was not working. The problem was fixed by OC Speaker repair, and traced back to the crossover connections which were not connected properly by the prior owner who had undertaken some questionable repairs. Fortunately , the tweeter was in working order.
When I got the crossover back, I noticed the "right" speaker does not plainly label which is the "positive" lead, and which is the "negative " lead to the respective drivers, and I am not sure I hooked them up in phase.
When comparing the cabinet wiring from "left" and "right" to trace the colors to the same drivers for phasing/polarity purposes, I noted that the crossover wiring was a different gauge and color from speaker to speaker. Both speakers had the N333 crossover inside. The "left" speaker has a solid green positive woofer connection, a solid red tweeter positive connection, and a solid white mid connection. All negative driver connections were black. This is in complete agreement with the schematic you can find online for the N333 crossover.
However, the "right" speaker has a solid green wire for the woofer positive?, a green with black stripe for woofer negative?, a yellow wire for mid positive?, with yellew w/black stripe for mid negative?, and white for tweeter positive?, with white w/black stripe for tweeter negative? I cannot find anything online to determine why there was a change in wiring color, and to confirm which one is truly supposed to be the positive (solid?) and which one is truly supposed to be the negative (solid w/stripe?).
How can I know absolutely that I have the polarity correct and the speakers in phase. They sound really great, but I want it perfect. My electrical knowledge is very limited. I read some detailed posts on reversed polarity and other issues with vintage JBL’s and find it very confusing yet intriguing.
Thanks, Doug
P.S. I was the guy who recently sold the NOS Camel grill covers on Ebay for $503!!