Connect a 16 ohm and 8 ohm to a 5150?

[MetalSound]

Just got a 4x12" Diezel with G12K-100´s yesterday and am looking forward to connect it to my 5150 and the Mesa OS 4x12".
Unfortunately the Diezel box is 16 ohm. So how can I do it?

I drew some very nice pictures.

Can you tell me if this works?

if not would you give another possibility?
I didn´t pay much attention in school when it came to electronic stuff parallel and serial and ohms and so on....

 

[::XeS::]

The 5150's output are parallel so, if you connect the mesa at 8Ohm you have to connect the other 5150's output to the 8Ohm input in the Diezel, and select 4Ohm in the 5150 because

Total impedence (parallel) = (8*8)/(8+8) = 4Ohm

But I'm not shure how the Diezel is.....if it's only 16Ohm I suppose the 2 8Ohm input are for stereo purpose right? So it could be your case
Anyone else?

 

[TheSweetener]

You always have to look at the total impedance of ALL cabs you connect to the amp.
If you connect one 8 ohm and one 16 ohm cab in parallel the total impedance will be 5.33 ohm.

I would just go from the 4 ohm output of the amp to the Mesa followed by the Diezel (or vice versa).

If there's a possibility to run the Diezel cab in stereo (which means that you get two 2x12" cab with 8 Ohm each) you could also only use two speakers (one sde) of the Diezel cab. Then you have 4 ohm combined with the Mesa. For recording it should be ok to just use two of the speakers. For live playing it might be a drawback.

Hope that helps.

kohle

 

[MetalSound]

That´s too bad. I was afraid that it has to be that way.
So I can run the Diezel only in 2x12" ´cause it has a 16 ohm mono and 2x8ohm stereo input?

is there a difference between these two possibilities as i´ve never used the thru output from the mesa...

do i have to switch the 5150 to 4 ohm or to 8 ohm?

 

[::XeS::]

You have to know if the thru is a serial or a parallel ooutput.

 

[TheSweetener]

Did you read my post? What you get is 5,333 ohms. Just connect that to the 4 ohm output of the amp.
I've done that countless times without problems!

 

[MetalSound]

well I don´t know....it doesn´t say anything.

 

[MetalSound]

why is it 5,33? i thought (8+16)/2=12 ohms....?!?!

EDIT: ah, I see: Total impedence (parallel) = (8*16)/(8+16) = 5,33Ohm

right?

 

[TheSweetener]

Look here:

http://dl.getdropbox.com/u/531846/Impendanz.png

R1 is the impedance of the first cab
R2 " " " " " " second "

 

[Trevoire520]

You might be able to rewire one of the cabs and change it's impedance to match the other cab.

 

[Wolfeman]

Do what TheSweetener said.

Ohms in regards to tube amps/cabs has never been a direct science, as long as you are close you will be fine, and even that is debatable.