Polarity

[mtchyz250f]

I was checking the polarity of some speakers. A 2105H and one 2204, all my Peerless, Audax, Adire and Focal cones moved outward when placing red to positive.

Two 2105s and one 2204 moved inward after placing positive to red! I checked the 2204s at least 4 times each.

Is this common with JBL's?

Mitch

[1audiohack]

Yes that is the norm on the older JBL stuff. There are many speculated reasons. Cars used to be posative ground, in your house the black wire is hot, who really knows. Audio until recently has been a pretty unruly group, I mean it was not very long ago they finally decided that pin two was hot!

[mtchyz250f]

The crazy thing to me is that the two 2204's were wired differently from each other! I checked four times. I will check again tomorrow, because it is just too hard to believe.

[1audiohack]

Oop's I missed that part, strange indeed. The least likely reason can be told with a compass held by the dust cap.

[DavidF]

The crazy thing to me is that the two 2204's were wired differently from each other! I checked four times. I will check again tomorrow, because it is just too hard to believe.

The convention for years was an inward cone motion in reaction to a positive pulse. In recent years JBL had begun to migrate designs over the more common protocol of outward for a positive pulse. No idea if that was to include recone kits on older models.

I had a LE5-12 mid reconed a couple years back with a JBL sourced recone kit. Too my surprise it followed the outward-to-positive pulse format. Go figure, either JBL spec'd it that way or the supplier just wired it differently on their own. I had to mark this driver to remember it differed from an earlier version that is inward-to-positve.