jimbpilot Messages: 9 Registered: January 2016 Location: Conroe, Texas 77303
Junior Member
I have a couple of Kustom three tower JBL bass cabinets and I want to restore with JBL D-140 speakers. Does any body know the correct ohm speakers to use and the correct wiring ??
jimbpilot
If the cabinet has 3 speakers in it, you'll need 16 ohm speakers wired in parallel to get a 5.33 ohm load. 3 8 ohm speakers wired in parallel will get you 2.66 ohms......depends on the ohm load rating of the amp your using. Kustom amps run on a 4 ohm load, some of the newer amps on the market today run at 2 ohms.
Kustom_Bart Messages: 601 Registered: October 2010 Location: Greenville, MichiGUN
Senior Member
You can run one cabinet with it, but not two. The factory speakers were 16 ohm rated, Also ensure when using the JBL's that you check to make sure they are in phase as some of them the red was negative and the black was positive. Just something to watch for.
Bart's correct about the phase issue......I even had a JBL that still was different than the other JBL in the cabinet. Just to be sure either use the battery test or keep the back off the cabinet till you check to make sure all speakers are moving in the same direction. Taking all those screws out are a pain so you only want to do it once.
pleat Messages: 1452 Registered: June 2004 Location: Belding, Mi
Senior Member
I just reverse the red and black wires on JBL cabinets. This way if I run a JBL and an Altec cab for example side by side I don't get phase cancellation. It also takes all the guess work out of what cabinets have been changed and what cabs may be original wiring. JBL speakers when applying a positve voltage, the cones move inward towards the magnet. Most ever other brand of speaker the cones move outward with a positive voltage is applied.
As far as running two 3x15 cabinets, as Bart said, you'd have around 2.65 ohms total to the K200 head. I'd suggest running the K200 head to one 3x15 cabinet and from the RCA out or line out of the K200 to drive a 100 watt slave amp to drive the second cabinet. This way you have much more power and head room.
I remember when I was much younger, hauling 3x15 JBL cabs, way more weight than I'd want to move now days. I'm amazed I still have my back intact.