cab + loadbox?

[Low Sound Love]

Hey guys, need some wisdom here. I'm about to get an Ampeg SVT-Classic, which, as you all know, will run at 4 or 2 ohm. I currently have 2 Mesa ph212 cabs, each cab is 8 ohm. So as long as I run both cabs, everything is just fine.
Problem is that for smaller gigs, I'd like to be able to run just one cab, while still using the SVT. Now I was wondering if it is possible to combine one 8 ohm cab with a loadbox (eg. Mesa cab clone or Kock Loadbox). I know that those load boxes are rated to a max of 100 watt @ 8 ohm, but if the SVT is kept at a low volume would it be workable? Since there is a cabinet hooked up, the loadbox would not have to carry the full weight of the amp, right? Or am I about to fry 3k worth of gear?
Thanks for any advice!

 

[ThisBass]

I would assume the rms output of a somewhat cranked svt around 100 Watt at most. That is due to the crest of a bass guitar signal. IME the output is biggest at lower notes played on E string and/or B string rather then notes played on G/D strings. Thus the average output power depends somewhat on your playing style that I can't predict.

By the other hand the output power will be spread, 1/2 running into the cab and 1/2 running into the power soak.
I would expect rms power running into the power soak around 50 Watt at most even if the amp is cranked somewhat.

svt transformers are known for their forgiveness to some ohm mismatching. And if you dont't push lots of lows into the sound by eq then probably the 8 ohm cab's ohm response isn't significant different to a 4 Ohm cab that receives a excessive scooped or low boosted sound like reggae stuff. The average ohm response of a cab depends somewhat on sound settings. Bassy sounds will increase the impedance character that an amp will see on it's output terminals. So try to avoid bassy sounds at higher volumes and I'm pretty sure you'll be fine even with a 8 Ohm cab.

 

[BassmanPaul]

Load boxes are simply a waste of power converted to heat. Your amp works harder for the same volume level. Although I advise connecting a proper load to a tube amplifier I doubt that using a 8Ω 2x10 will cause irreparable damage.