|KJung ||10-22-2013 05:36 AM |
It depends. In this particular situation, you will notice a meaningful difference. The LMII/III is a great head, but its power management system results in a pretty hard limiting when you hit its maximum output. So, that, combined with your large, moderate sensitivity cab, would result in a meaningful increase in volume (not massive, but 2db is quite noticeable... remember db is a log scale), and (this is the important point) much less compression in the low end when pushed. It can be a life changer.
So, if you are 'almost loud enough', but get frustrated at the end of the night when you are pushing a bit, and you tend to hear your low end compress a bit, the identical cab in 4ohms would result in (IME) a meaningful improvement for you without having to carry more gear (like a second cab).
HOWEVER, if you get a DIFFERENT model of cab at 4ohms, then all bets are off, since the sensitivity of a different model would have to be taken into consideration (in other words, a cab that takes more watts to get as loud as your current cab to reach the same volume might 'eat up' the additional watts you would get from running your head at full power/4ohms.
As I've posted many times, you are best to ignore those posters who are taking about general absolutes (i.e., it never matters or it always matters). It depends on a complex combination of absolute wattage of the head, SPL/efficiency of the cabinet, mechanical capability of the drivers, and power management of the head in question.