Running 2 cabinets with Herbert - load/impedance

[nbarts]

This is a question about amps in general & Herbert particularly in this case.

I'd like to run 2 cabs with Herbert, but their impedance doesn't match as well as the wattage. In this particular case one is Mesa Rectifier 2x12 8ohm 120W & the other is Bogner Cube 1x12 16ohm 60W. Is it alright to run this 2 cabs together & if so which outputs should I use?

 

[duesentrieb]

1/8 + 1/16 = 2/16 + 1/16 = 3/16 --> 1/R1 + 1/R2 + 1/Rn = 1/R

16/3 = 5.3333 --> reciprocal = R

plug both into the 2x8 (=4) speaker outs.

On the back you have (left to right)

1-2-3-4-5
1 and 2 are 4 Ohm, both wired parallel, so if both are used, both cabs should be 8 Ohm each
3 and 4 are 8 Ohm, both wired parallel, so if both are used, both cabs should be 16 Ohm each
5 is 16 Ohm. For a single 16 Ohm cab

you need to plug into 1 and 2, cause your overall impedance is 5.3 Ohm and you'll feed the 4 Ohm of the transformer this way.

yes, its safe.

 

[nbarts]

Thanks!

 

[jswevers]

Can't you expect an unbalance in loudness if you connect a 16 Ohm and 8 Ohm cab. This will not harm
you amplifier but is maybe not desirable if you are playing since maybe you will hear very well only one of them ... the 8 Ohm cab I guess ...

 

[nbarts]

I'm thinking disbalance will be there, but I don't think it's gonna be like hearing only one of them.

I'll give you some more practical answer very soon. Didn't have time to try it yet.