I have an opportunity to buy a Kustom 3x15 cab with original JBL's. The seller will not allow me to open the cab but I did test it and it sounded great. My question is:
What is the impedance of each speaker and what is the total impedance of the cab?
stevem Messages: 4652 Registered: June 2004 Location: NY
Senior Member
Each speaker if original is 16 ohms.
All three are wired in parallel so with a ohm meter hooked up to a short length cable at the jack you should read less then 6 .5 ohms like 5.3.
If you get a telescoping mechanics mirror you can stick it in one port and put a small flashlight in the othe port and see for sure what's in there.
It could be a bass cab and loaded with D140 JBLs, or it could be a guitar cab and loaded with D130 drivers.
pleat Messages: 1445 Registered: June 2004 Location: Belding, Mi
Senior Member
If the cabinet has a slant when viewed from the side, the cab would be for the K200/K400 series amp heads and the speakers are 16 ohm each for a 5.6 ohm total impedance.
If the cab has sliver threads running through the grill cloth and no taper on the side of the cabinet, that cab would be for the K250 series amp heads, and the speakers are 8 ohms each and a total of 2.7 ohms.
Thank you for the replies and info. The plaque on the back at the jack says: D130F, so I assume this is a guitar cab andnot a bass cab. The sides are straight, not angled, though I do not recall seeing any silver thread in the grill cloth. All black cloth
stevem Messages: 4652 Registered: June 2004 Location: NY
Senior Member
Yes, it's a guitar cab then with the 130s.
The straight/ vertical front is a early 250 type cab.
There was a point in late 1971 or early 72 where the standard black tuck & roll being used had a much courser texture to it then previous and I believe this is also when the grill cloth with the silver strands in it started to be used.