I've pulled 21oz from a 350w LED at 40% efficiency. Any decent 600w cob lamp these days should be able to pull 2. I assume the reason your Amare didn't do better is that you didn't have the plants in a reflective enclosure and the light was way too high if I remember correctly. Lenses/reflectors help but it's still a 80 or 90 degree cone.
The differance is Rahz, while you're talking about the probability of 600w cob lights pulling 2#'s by multiplying 1sq' yields by 16 to determine a 4'x4' harvest, me & other poeple are actually showing the real results in real life, live. Not to mention my Cloak pulled that out of 32"x4' w/ 4 medium/small plants.
And you must not remember correctly either. Cuz my Amare exceeded my realistic expectations, was not to high & had white walls on 2 sides. Like, did you even see?
And as far as your 21 oz. harvest off a 350w. Led, what, do you own the first SE-350?
I really wish you & Stephen would stop saying these cob lights yield 2#'s off 600w or less, like its to be expected. Where are all these magical harvests? Some you-tube guy counting popcorn, branches & exaggerating?
Don't get me wrong, I've seen some good yields but you guys talk like its a normal thing every cob grower experiences.
Fact is, almost every single SunCloak harvest recorded is 2#'s. Yes. It's absolutely normal. Not a 1 n 30 grows thing.
When a light consistently yields those kindve #'s when others are not, then it is a more efficient means of growing. That's why I say it's probably the most efficient light available.