Whew, tough crowd over there in that Multi Way forum! Never got hate mail PMs before that thread.

It is very hard to have a conversation with all the topic cops and Parts Express catalog hit men lurking in the shadows. Pano deserves battle pay.

To think I went over there because I was interested in Altec field coil conversions...wound up fighting off idiots who think they are scientists but they are more like the Taliban.

Best way to look like a moron is to argue with morons, so I am guilty myself.

Definitely makes me appreciate the civil and friendly attitude on this board all the more!!!

Steve, appreciate your comment on the mechanical aspects. Where I am trying to get to is Lansing territory. That is a good place to be. Back in the day, I did compare Lansing 415s and 287s with the original Altec PM versions and it was a night and day difference.

Lansing was my main system for a few years. Now my parts are in the Silbatone museum. I'm trying to push to set this stuff up and reevaluate it, maybe take it out to a few shows so people can hear the glorious Lansing sound. That was some really great sounding theater gear.

Granted there are other differences in the drivers besides the motor, including those beautiful roll surround Lansing diaphragms, but they do share strong family resemblances.

So, maybe it wasn't a tightly controlled lab experiment but it was enough to teach me to think for myself and trust my listening experiences. At least I did the experiment. Thankfully, I was lucky enough to have that opportunity in the pre-ebay good scavenging days. It would be difficult and crazy expensive to assemble all that ancient stuff now.

The most compelling technical argument I saw for field coils discussed overload conditions and recovery characteristics of various magnetic materials. Most well-behaved were electromagnets, followed by AlNiCo, ferrite, and neodym in that order.

Now if only I could find that study again....does this sound familiar to anybody?

I tend to speculate that the presence of an external power source for the magnet forces the system back into line, but this is just a mental picture that I like.