Question about running two speaker cabs.

[Gjeven]

This question probably applies to all amplifiers...but anyway.

I have a 16ohm 2x12 and an 8ohm 2x12. Would it be possible to run both cabs in the CCV, would I plug the 16ohm cab into the 8ohm plug in the back of the amp, and the 8 ohm cab into the 4 ohm amp plug. Similar to what I'd do for a safe mismatch on my Mesa head.

 

[glip22]

I could be wrong. I think you might be running a mismatch if you do that. Rewire the 8 ohm cab in series if they are 8 ohm speakers cab to match the other. Normally you would plug two 16 ohm cabs in the 8 ohm out jacks or two 8 ohm cabs in the 4 ohm outs. You have to half the impedance when running two cabs as you know. I am not sure if the OT is safe doing as you would like. Not hard to rewire.

 

[steve_k]

A 16 and an 8 is a 5.3 equivalent. Run both in the 4 ohm jacks.

 

[charveldan]

Not a good idea, if it were mine i wouldn't.

 

[charveldan]

A 16 and an 8 is a 5.3 equivalent. Run both in the 4 ohm jacks.

Agreed. Knowledge is power. A 1.3 difference is nothing at all and actually less than most 4x12 cabinets. Most 4x12's are around 12-13 ohms and people use 16 ohm at the amp. I bet Charvel Dan is using a higher mismatch than the OP question....

Actually you make a good point, my G12M 25 watt Blackback cabs DC resistance measures about 13.6 ohms which i run off the 16 ohm tap.

I was always told when it comes to cabs, you can run more ohms, but not less, if needed. But i was also told that when measuring DC resistance things like the wire harness & voice coil wire diameter are factors, meaning that the 13.6 reading is prolly closer to 15 than 13.

 

[steve_k]

DC resistance does not equal impedance. Close, but not the same measurement.

 

[glip22]

A 16 and an 8 is a 5.3 equivalent. Run both in the 4 ohm jacks.

Agreed. Knowledge is power. A 1.3 difference is nothing at all and actually less than most 4x12 cabinets. Most 4x12's are around 12-13 ohms and people use 16 ohm at the amp. I bet Charvel Dan is using a higher mismatch than the OP question....

Actually you make a good point, my G12M 25 watt Blackback cabs DC resistance measures about 13.6 ohms which i run off the 16 ohm tap.

I was always told when it comes to cabs, you can run more ohms, but not less, if needed. But i was also told that when measuring DC resistance things like the wire harness & voice coil wire diameter are factors, meaning that the 13.6 reading is prolly closer to 15 than 13.

Listen to Steve, He knows what PI is possibly better than anyone on the board

 

[charveldan]

It's weird, i had a 50 watt JMP back in the 80's that i fried the 8 ohm tap, and i'm not even really sure how i did it, but i used to run all kinds of cabs.

Ever since then i've almost had a Superstition about matching impedance.