View Full Version : 3115A Inductor?

01-14-2009, 05:16 AM
I would like to ask if anyone, ever measured the actual iductance of the multitap inductor as used in 3115A crossover. I am about to build this, but it is impossible to find any hard data on this. Any help?

01-14-2009, 05:36 AM
Courtesy of David Smith

01-14-2009, 06:12 AM
Wow! that was fast!
Exactly what I needed, is this measured or calculated? Also, do you possibly have any ohm reading of the entire choke and maybe the gauge of the wire used?

Thanks again,


01-14-2009, 06:15 AM
Calculated. David made the spreadsheet for us. I don't have one of those coils on hand anymore so I can't tell you the gauge or DCR. The standard DCR answer from JBL is that they always tried to keep normal inductors around 0.5 to 0.6 ohms DCR. Greg once said that each tapped autotransformer was set by hand by the techs in the factory.

01-14-2009, 06:20 AM
That is enough info anyway, 0,5-0,6ohm is easily achievable, maybe I can try to achieve this even with no laminations.

Thanks again