Valve Amp - Adding extra cab

[BassAdder60]

A curious question regarding Tube amps ( heads )

I believe a tube amp gives out it’s output regardless of speaker load unlike A/B or Class D 

So is there any perceivable gain adding an extra matching cab in terms of volume ? In terms of power the tube amp is still the same wattage out but is the volume increased ? 
Example Ampeg V4B with SVT212AV with added SVT212AV cab ? 
 

If so that may become my main rig assuming I can get two cabs in the car ! 

 

 

[Bill Fitzmaurice]

Yes, because the added cone displacement of a second cab gives a sensitivity boost.

[BassAdder60]

1 minute ago, Bill Fitzmaurice said:

Yes, because the added cone displacement of a second cab gives a sensitivity boost.

Thanks Bill 

 

Is it a noticeable increase ? I know it’s all subjective but a rough idea would help ? 
 

[Bill Fitzmaurice]

It was always very noticeable for me when I last had a valve amp, a Fender Bassman. That would have been around 1970.

[Downunderwonder]

Much easier to hear yourself with a tall stack also. I am pretty sure I started lowering my overall volume when I got stacked.

 

It's conceivable you could wind up with actual headroom that can be used for dropping the odd bomb, I mean artful dynamic accented low note. Use sparingly lest you inspire guitard to double his rig also.