DIY 802 field coil drivers may be a reality!!

[LowOhms]

Sorry Jeff, but I have a tale to tell. Hope you don't mind.

When I first received an RCA MI-1428B field coil compression driver nearly twenty years ago and found that it sounded terrific, I searched for info on the web. The only thing I found was a post from Jeff on a reconer site, where he indicated that he was looking for recone parts for the RCA 1400 series woofers and compression drivers and that "top prices can be paid for these parts."

I wrote to Jeff and he responded that he was willing to tell me everything he knew about these drivers, but that I had to agree to "never tell another living soul." I responded that I was a free flow of info kind of guy and could not agree to those terms. A day or so later he responded at length that the RCA compression driver possessed the best midrange on earth, and that he didn't want this getting out as he had set himself and several friends up with them at minimal cost and wanted this to continue. I kept quiet for several years, but after my business partner and I began manufacturing a modern version of the MI-1428B I spilled the beans online.

Now everyone has a right to change their mind, and apparently Jeff has moved on to Alnico magnet drivers. But I am here to tell you that this was not always the case!

Thats a cool story Steve !! Hope you are well.

Today, I am very satisfied with my ( re-magnetized by GPA ) 802D , that not only has an alnico magnet, but a non-phenolic diaphragm.

As I say here " all the time " Steve, speakers aren't the weak link. Its MAINLY amps, but also wiring and the crossover implementations going to the drivers. One can " lose it " any wheres in that chain, preceding the driver.

I had a HUGE discovery on my system just yesterday to share with others, on speaker wires - amp to the crossover. I run 114 1/4 inch triple 12 AWG Mil Spec, each polarity individually lightly twisted around itself, but the two polarities are " not to touch each other ".

Turns out, I had both channels polarities each touching each other, in only one location on the way to the crossover. AS SOON as I had them totally separated, not touching at all, ( amp to crossover ) I got a NOTICEABLY better sounding overall result through my system. Dynamics were improved, as was timbre, and distortion seemed to be reduced. Just simply NICER to hear !!

Next, I realized I had neatly bundled the secondary wires of the output transformer, ground-4-8-16 Ohms....all bundled together . It looked so nice. Aircraft style.

I cut apart all the bundling material, one channel at a time, on this 4.5 inch run (of the Output transformer to the amp's output terminals ), so the wire polarities didn't touch each other.

I listened each time, to each channel's incremental wiring change, on VOTTs to familiar " reference " listening-material. Got an improvement in sonics, each time ! The improvement in listening, cumulative, before and after, on piano, voice, etc, was truly MOST worthwhile. We all live and learn. Performance ..... for free.

"Transfer efficiency" rules..... AND " an inch of bad ( or mis-applied wire )" can ruin the musical experience. I have discussed that often up here....was cool to experience these cumulative positive effects yesterday.

So now, Steve, in 2017, I often share information for free. Will people make use of it? That remains to be seen ! Likely, only a few.


Low Ohms...... Jeff Medwin