Hi bluelobster,
Looks like I was wrong to assume there was just a single series inductor in the woofer circuit of the N1201-8a.
Here's the schematic , as laid out by Jim Easley, this was downloaded from
Jeff Markwarts' Corner "Web-Page"
- As you can see, an upgrade to better inductors in the woofer circuit involves replacing 2 inductors. Jeff recommends better parts compared to my own articulations.
- Also, here's what the inside looks like of the N1201-8a crossover, with the "cowling" removed.
- Here's a picture of the insides of a N1209-8a that I own. The 25¢ piece is added for scale , along with a 16 or 18 gauge / 1.6mh coil . As you can see the inductors / coils / "chokes" are physically quite small inside the crossover . Retrofitting in better ( larger ) types will be a challenge .
- Here's a picture of the insides of one of the two types of cap found in these crossovers. You can see from the picture that its dielectric type is "Paper in Oil" . The other dielectric type "made by Callins" is still unknown ( since I haven't yet "sacrificed" a cap to find out ). When I opened this other cap (about 2 months ago ) there was already some "oxidation" to the most "oiley" portions. My point ??? most likely, all these 20 to 40 year old "paper in oil caps" should be replaced - unless a person can check them out and verify that there's no "capacitance drift". FWIW ; I've heard some pretty nasty "resonances" ( in the past ), particularly on female voices, when auditioning these ( aged ) surplus-type "PIO" caps.
regards <> Earl K