2 cab speaker ohms and 8ohms one 4

[slystewart]

Ok have a Ampeg SVT 2 Pro using one 4 x 10 Ampeg cab at 4 ohms and one 15 inch Orange at 8 ....on the back of the amp switch there for 2 or 4 ohms so left it on 2 so I guess the speaker load is somewhere about 3 ohms.....is this a problem for this amp thanks any info

[waynepunkdude]

You should have a matched load with valve amps.

[BassTractor]

What Wayne says.
If you still are going to mismatch actual impedance (2.67 Ohm in this case) with output transformer impedance, then it is normally a better idea to have the cab have less impedance - not more as one would expect due to experience with solid state power stages.
That would mean connecting it to the 4 Ohm output.

[b]However[/b], I have no idea how flexible the SVT is, and in this case choosing the 2 Ohm output might be better.
I know this is of little help, but I thought mentioning the general idea was better than not mentioning it.

Maybe a pro chimes in.

[4 Strings]

Not a pro, but I do understand that the impedance is a nominal figure which changes with frequency. Lower frequencies result in lower impedances, the 4Ohms is a nominal average. You may never be operating at 2.67Ohms.

I suppose an extended question would be 'what are the warning signs if the impedance is too low?'.

Back to waiting for a pro.

[BassTractor]

[quote name='4 Strings' timestamp='1377220229' post='2185040']
Not a pro, but I do understand that the impedance is a nominal figure which changes with frequency. Lower frequencies result in lower impedances, the 4Ohms is a nominal average. You may never be operating at 2.67Ohms.
[/quote]

Yup. It differs by frequency, and is represented by a curve, and that curve has relative changes with excursion. One can never talk about one impedance curve. It's a set of curves.
So yes indeed, it's a very nominal figure. Still one that I wouldn't dare taking lightly, but I'm no pro either.

[xgsjx]

Why not sell one of the cabs & get 2 the same?