well, everybody seems to be using 3500k cxb3590 CD bin these days, so I bought those. but I am now digesting this thread that I missed while on Thanksgiving holiday:
https://www.rollitup.org/t/top-bin-cob-comparison.891010/
Now I am thinking / definitely ordering a few CXB3590 5000K CD bin to throw in my mix. along with this PCB project to add some 660nm deep reds.
And if I am not happy, next step would be switch all (32) of my 3590s from 700ma to 1400ma and blast bitches titties off. kind of like a stereo so loud it will blow girls cloths off, but with leds.
It all started with pico and the vero v1 and his blind love for bridgelux. Very shortly after MrFLux came out with his analysis of the cxa and some other well known/used chips. His analysis along with SDS also showed some key ratios that kind of set 3K as the "golden ticket"...and so the revolution began.
When I got into it it, my second move was enhance the spectrum to something like what I was familiar with...apache. After small scale with straight 4K, I wanted to do 4K+630/660 full scale. There was a delay with my divers for the reds so I started with straight 4K and finished it out. The run turned out great and settle some things that plant physiology and I have been preaching for a while...photons are king. This carried on and ways of reaching the efficiency mark(~50%) were really explored. Right around here optics and amare were showing up, optics was very basic DIY based, Amare had/has something, but some weak links imo, but had the right idea.
This was all furthered by the cxb, which came in a general increase in output, as well as a specific extra bin in 3500K, allowing a warmer temps that held superior efficiency. This really negated the "need" to enhance. As well as 3590's being seriously available with the cxb...photons came even easier.
What's got many blinded and on the easy path is, that we have surpassed hps by a good point now, and have relaxed a bit imo. As well as red starting to be a good bit behind in efficiency, has mislead people some. I also speak from a lot of AT experience(W3:R2) which has given me superior quality to anything plain cobs have given(barely, but it's there). And was very productive despite it's lower efficiency.... (~39% compared to ~47%) and more compact design. Keep headed where you're going, it's the right path.
Your PCB(4 top bin 660's at 700ma)...
With a 5700K...
At 1400ma
At 700ma
With a 4K...
At 1400ma
At 700ma