[Doug Houston]

Real quickie here. I'm trying to ride about 5 horses at once here, so the Jensen speaker project is going slow.

Got another theory about the dual fields. You never hear of them on lower ticket sets, so I just wonder about this.

Flux level in dynamic speakers was hard to get in high levels back before some of the super magnets that came to be in the WW II days and up to now. It appears that the series field winding did an accptable job in must sets, but a stronger field was desirable for the ultra-fine sets like the Scotts and McMurdos. Those power amps were running class AB. The shunt section of the field brought more flux level, and the resulting efficiency that they wanted I find that on some juke boxes, there was a shunt field used. I have an old Wurlitzer amplifier that has P-P 45's in the output, but with a 45 driver. That would have meant that Wurlitzer was pushing the 45's into class AB, and a shunt field would do the job better. It was a 1936 model. Today, a good PM speaker would do the job perfectly.

I have a pair of 18 inch speakers on my living room systems, and I can barely lift one of them. The magnets are the heaviest part of them.