Specific Ohm Question - Ampeg SVT and Cabs

I think your ohms with both cabinets would be 2.67 ohms total load and I would think you should be just fine.

 

I have a similar setup myself, the SVT head and two cabinets. Both my cabs are 4 ohms each, but I was contemplating a setup which total ohmage would be the 2.67 that you'll be experiencing. This is an email I shot to Ampeg a little while back, also from a thread posted a while back as well:

Ok, so I shot Ampeg an email regarding this subject, here it is:

On Oct 31, 2007, at 9:47 PM, Bob Thiemann wrote:

> Hi, I'm a proud user of a wonderful SVT-CL and have been for many
> years. I had a couple of questions for you regarding the SVT-CL and
> playing through cabinets with mismatched ohms. I read on the
> www.ampeg.com FAQ page that it can be done, but is not recommended.
> But I would like to know what kind of consequences I would be facing
> by running a 1000watt 4x10 bass cabinet at 4ohms with a 500 watt 2x10
> bass cabinet on top rated at 8ohms. I know the nominal impedence
> would measure at approx. 2.667ohms. The SVT can be used at either 2
> or 4 ohms, both at 300watts RMS. I imagine the amp would be safe to
> run at 2 ohms for this application, dispensing 2/3rds of the overall
> power to the 1000 watt 4ohm 4x10 and 1/3rd to the 500 watt 8ohm
2x10.
> I'm not an expert on this sort of thing, so any input as to the
> severity of the possible consequences would be appreciated. Thanks!
>
> Bob THiemann

Here's what they shot back:

Hi Bob,

That's a pretty darn good explanation for someone that's not an
expert!!!!!!

That really is the only "bad" consequence is that the 8 ohm cab won't
get as much power allocated to it as the 4 ohm cab really. As far as
any detriment to your CL, there really isn't any. You might go through

power tubes a bit more prematurely but the difference would be pretty
nominal.
Just be sure to have that impedance switch set to 2 ohms and your CL
should be happy.

Hope this helps and feel free to hit me back here anytime should you
have any questions!

Best Regards,

Dino Monoxelos
Global Ampeg Product Specialist
LOUD Technologies Inc.


Hope this helps!

 

Chech this thread: (note Psycho Bass Guys responce in post #13)
http://www.talkbass.com/forum/showthread.php?t=439371