Road King Cab Question

[metalmm785]

Hi all,

I recently got a 4x12 Road King Cab and I was wondering if anyone ever measured the output jacks with a multimeter on one of these? I measure mine out of curiosity and both the closed-back and open-back jacks gave me measurements of around 6-7 ohms, which seems in line with what a normal 8-ohm jack measures.

However, the combined jack (close back + open back) gave me a reading of 6.3. This is supposed to be the 4-ohm jack on this cab. Shouldn't I get a much lower number than that? I was expecting something in the 3 range. All speakers are stock (2 MC 90s and 2 Vin30s) rated at 16 ohms.

 

[Theresa]

Close enough... If you're using a Road King, it takes the impedance without any issues.

 

[electric mayhem]

Hi all,

I recently got a 4x12 Road King Cab and I was wondering if anyone ever measured the output jacks with a multimeter on one of these? I measure mine out of curiosity and both the closed-back and open-back jacks gave me measurements of around 6-7 ohms, which seems in line with what a normal 8-ohm jack measures.

However, the combined jack (close back + open back) gave me a reading of 6.3. This is supposed to be the 4-ohm jack on this cab. Shouldn't I get a much lower number than that? I was expecting something in the 3 range. All speakers are stock (2 MC 90s and 2 Vin30s) rated at 16 ohms.

I'm with you on your expectations. Do the 9V battery test and see which cones are moving. 4x16 = 4 or 16, not 8ohm and 6.3 resistance implies 8 impedance as you're thinking.

I have one put away with a cover on it. If I can get a meter on it without moving a bunch of stuff I'll check it later.

 

[metalmm785]

I'm with you on your expectations. Do the 9V battery test and see which cones are moving. 4x16 = 4 or 16, not 8ohm and 6.3 resistance implies 8 impedance as you're thinking.

I have one put away with a cover on it. If I can get a meter on it without moving a bunch of stuff I'll check it later.

So all 4 speakers are working when using the 4ohm jack. I was wondering if you had a chance to check your cab to see what reading are you getting on yours with a multimeter?

 

[electric mayhem]

So all 4 speakers are working when using the 4ohm jack. I was wondering if you had a chance to check your cab to see what reading are you getting on yours with a multimeter?

I spaced it. While I locate mine check your driver ohms again. Did you take a pic of the V30 t-code or ohm stamp at the spade connects? The MC90's are easy enough to see. I'm wondering if someone changed any drivers.

That said you can't get 6-7ohms each for 2 driver pairs and 6-7ohms for the same quad.

 

[electric mayhem]

The RK cab is in pretty tight with some smaller cabs on it. With the cover on I'll have to move some things around which I should be able to get to this week.

 

[electric mayhem]

So all 4 speakers are working when using the 4ohm jack. I was wondering if you had a chance to check your cab to see what reading are you getting on yours with a multimeter?

I measured the RK.

3.7 ohm 4x12
6.7 ohm open
6.7 ohm closed

Maybe de-oxit innie-outtie on the 4ohm jack? I'd say maybe a jack that isn't switching correctly yet you said all 4 cones are moving. You could check the wire connects at the jack plate and driver spades You're not going to hurt the amp if the speaker ohms are higher.

 

[metalmm785]

I measured the RK.

3.7 ohm 4x12
6.7 ohm open
6.7 ohm closed

Maybe de-oxit innie-outtie on the 4ohm jack? I'd say maybe a jack that isn't switching correctly yet you said all 4 cones are moving. You could check the wire connects at the jack plate and driver spades You're not going to hurt the amp if the speaker ohms are higher.

Thanks a lot for checking. That reading seems to make more sense. I checked the wires and V30 speakers inside and they seem correct at first glance. Strange that mine is higher. I will de-oxit and see if that does anything.