Here are some real world spl test of a Stetsom 7k

TEST: Stetsom 7kd 16v version vs. 7kd 12v version.

What you need to know. Stetsom 7kd 16v at .5ohms test is NOT full Power. The 16v version needs to be run at .25ohms for full power.
All test done on CS9000 battery (equal to 1.5 hawker 2150's)

First: 7kd 16v @ .5ohms

Average power 4500w
153.4db consistent
Average voltage drop. 11.8-11.9v

Second: 7kd 12v @ .5ohms

Average power 5300w
Average voltage drop. 11.3-11.4v

Third: 7kd 12v @ .7ohms

Average power 5100w
Average voltage drop ((11.6-11.7v))

Summery: The 16v and 12v version are a wash for power because the 16v 7kd gains about .5db going to .25ohms from .5ohms. When the 12v version was run lower than .5ohms it lost all efficiency and just ****** more voltage.

BUT!! The 7kd 12v version run at .7 only looses .1 at most .2db but gains .3 to .4v of efficiency.

Compare test 1 and 3: The 16v 7kd @.5ohms does 4500w @ 153.4db and the 12v version @.7ohms does 5100w @ 153.8-153.9 but only drops .2v more from the 16v 7kd at .5ohms.

Conclusion: The 12v 7kd is more efficient than the 16v version and does it at a higher ohm load. This is great news for people running NSB90,Powermaster D3100, Hawker 2150 or smaller batteries. Biggest difference is if you plan on running more than 2 amps on one battery they will do a lot better then the 16v 7kd.

Also anything above 1ohm for music on the 12v version is a big gain compared to the 16v version. So far at 1.4ohms on 12v to 1.4ohms on the 16v is a 1db difference. And the more battery you add to either one of these amps they keep gaining power. I have yet to see these amps stop gaining power with added battery power.