COB VS SMD CREE - CXA 3070/CXB3590 vs 5W XP-G2

Hello all.
Serious LED DIY question.

I see tons of COB builds which obviously work well.
I also see alot of hate on single diodes, mainly non Cree.
From my research and perspective the best single diode is the Cree XP-G2 80CRI.

Strictly speaking 3500k.

For comparison lets say we have 3 panels all at 600w from the wall running at 700mA;
Light 1 - CXA 3070
Light 2 - CXB 3590
Light 3 - XP-G2

What would be your reason for choosing COB over thru XP-G2 5w SMD and vice versa.
I am well aware the price differences on all 3 as well as the CXB being alot more expensive than the CXA.

Would love to understand why COBS over high end CREE SMD when they are more affordable, high PAR and PPFD and 80CRI. In addition, it seems coverage and stable PAR can be achieved with CREE smd more affordably than COBS.

Would love to hear from @Greengenes707 and @Growmau5 @SupraSPL @REALSTYLES on the subject due to the far superior understanding on electrical and LED.

Seems Area 51 is also using the XP-G2 , but I also see Advanced using the older XTE making claims as if thru fixtures as the newest BIN....

So I hope this can clear up some confusion on my end and others who may be asking similar questions regarding high end COBS and SMD diodes.

Good vibes , Trippy

COB is way simpler to montage.
Just 2-4 holes for 1 cob and it's all done, SMD is a lot more work.

And using the Cree calculator...
http://pct.cree.com/dt/index.html

The best bin for XP-G2 @ 80cri is R5
At 350mA it does 155 lm/w but it's only a 1 watt light.
At 700mA it does 135 lm/w but again it's still just a 2.1 watt light.
You will need 300 of them for a 600 watt light.

The CXB 3590 3500K CD bin (72V) version has 172 lm/w and is a 48. watt light.
The 36V version has a higher lm/w but is just a 24 watt light at that current.

(CXB is the same as CXB but a better bin, the CXB3590 is more expensive than the CXA 3070 because the 3590 is bigger and badder)
The CXB3070 BB bin at 700mA is 183 lm/w and is 23.6 watts.

COBs are much cheaper when you need high power.
They're also more efficient unless you drive the SMD ultra low, in which case they're the same but I wouldn't call 0.2 watt lights practical for growlights

"Would love to understand why COBS over high end CREE SMD when they are more affordable, high PAR and PPFD"
Untrue statement.
SMDs cost more per watt.
And COBs are more efficient generally.

COBs cost less per watt and are more efficient.
For growlights white SMDs are obsolete, only far-red and UV SMDs may still have a place

frica said:

COB is way simpler to montage.
Just 2-4 holes for 1 cob and it's all done, SMD is a lot more work.

And using the Cree calculator...
http://pct.cree.com/dt/index.html

The best bin for XP-G2 @ 80cri is R5
At 350mA it does 155 lm/w but it's only a 1 watt light.
At 700mA it does 135 lm/w but again it's still just a 2.1 watt light.
You will need 300 of them for a 600 watt light.

The CXB 3590 3500K CD bin (72V) version has 172 lm/w and is a 48. watt light.
The 36V version has a higher lm/w but is just a 24 watt light at that current.

(CXB is the same as CXB but a better bin, the CXB3590 is more expensive than the CXA 3070 because the 3590 is bigger and badder)
The CXB3070 BB bin at 700mA is 183 lm/w and is 23.6 watts.

COBs are much cheaper when you need high power.
They're also more efficient unless you drive the SMD ultra low, in which case they're the same.

"Would love to understand why COBS over high end CREE SMD when they are more affordable, high PAR and PPFD"
Untrue statement.
SMDs cost more per watt.
And COBs are more efficient generally.

COBs cost less per watt and are more efficient.
For growlights white SMDs are obsolete, only far-red and UV SMDs may still have a place

Click to expand...

Thanks for that info.
White smd are obsolete? Area 51 as well as spectrum king use Cree white led.
I am no expert, but this begs the question. Why are they mot using COB if the price is much less?
Also lumens are irrelevant here for plants. Generally speaking PAR and ppfd. Thanks for the info. Would also love some others opinions on the subject.
Also 300 XP-G2 is actually cheaper for a 600w 700mA than CXB3590 at same wattage.
All depends on where you shop.
I am Canadian its 90+$ per COB... so its slightly cheaper for smd than cob in this country.
Glad you filled me in though.

Trippyness said:

Thanks for that info.
White smd are obsolete? Area 51 as well as spectrum king use Cree white led.
I am no expert, but this begs the question. Why are they mot using COB if the price is much less?
Also lumens are irrelevant here for plants. Generally speaking PAR and ppfd. Thanks for the info. Would also love some others opinions on the subject.
Also 300 XP-G2 is actually cheaper for a 600w 700mA than CXB3590 at same wattage.
All depends on where you shop.
I am Canadian its 90+$ per COB... so its slightly cheaper for smd than cob in this country.
Glad you filled me in though.

Click to expand...

Because people still buy those panels.

And CXB3590 @700mA vs 300 xp-G2 is not a very fair comparison either way since the CXB is much more efficient at that current so you'll need less watts and thus less cobs besides saving on your energy bill.

I'm comparing lumens because since they're Cree chips with similar colour temp they're likely going to have near identical colour spectrums.

Edit:The only reason why Cree cobs can be more expensive than SMD counter parts is probably because of the demand for cobs driving up the price. Manufacturing process of COBs is simpler than SMDs

You should also try looking at Bridgelux Vero chips.
They're a lot cheaper than Cree cobs but only slightly less efficient when driven hard.

So let's throw something like these in the mix. Lots of companies make these. Very good way to get some discrete light thrown into corners and smaller spaces. Priced right you could probably do entire grows with these, if you wanted.
http://www.ledinside.com/products/2016/2/lumileds_launches_new_high_efficacy_module_for_outdoor_applications



LUXEON XR-TX module, incorporating 12 LUXEON TX high-efficacy LEDs to produce 3300 lumens and 140 lm/W at nominal drive conditions*

I would use those all day for vegging, but I am liking the high power shit for flowering.

frica said:

Because people still buy those panels.

And CXB3590 @700mA vs 300 xp-G2 is not a very fair comparison either way since the CXB is much more efficient at that current so you'll need less watts and thus less cobs besides saving on your energy bill.

I'm comparing lumens because since they're Cree chips with similar colour temp they're likely going to have near identical colour spectrums.

Edit:The only reason why Cree cobs can be more expensive than SMD counter parts is probably because of the demand for cobs driving up the price. Manufacturing process of COBs is simpler than SMDs

You should also try looking at Bridgelux Vero chips.
They're a lot cheaper than Cree cobs but only slightly less efficient when driven hard.

Click to expand...

Thanks for clearing that up.
This was a question due to the fact that I'm building a 10 x 10 room for flowering.
Just wanted to get comparison . Thank you shed some light on this topic

frica said:

Because people still buy those panels.

And CXB3590 @700mA vs 300 xp-G2 is not a very fair comparison either way since the CXB is much more efficient at that current so you'll need less watts and thus less cobs besides saving on your energy bill.

I'm comparing lumens because since they're Cree chips with similar colour temp they're likely going to have near identical colour spectrums.

Edit:The only reason why Cree cobs can be more expensive than SMD counter parts is probably because of the demand for cobs driving up the price. Manufacturing process of COBs is simpler than SMDs

You should also try looking at Bridgelux Vero chips.
They're a lot cheaper than Cree cobs but only slightly less efficient when driven hard.

Click to expand...

I have herd good thongs about Vero.
Yes seems price is going hopefully it comes back down soon. Paying 90 a cob in my currency s quite absurd.

You have to look at cost and efficiency to get a good par comparison. The CXB3590 CD bin at 2.1 amps (75 watts) is 160 LPW, slightly better than XPGBWT-H1-0000-00HE7 at .35 amps. At that current it would take over 75 XP-G2s to equal the cost/performance margin.

Rahz said:

You have to look at cost and efficiency to get a good par comparison. The CXB3590 CD bin at 2.1 amps (75 watts) is 160 LPW, slightly better than XPGBWT-H1-0000-00HE7 at .35 amps. At that current it would take over 75 XP-G2s to equal the cost/performance margin.

Click to expand...

Very informative. What is your take on Vero 29 vs cxb3590 at cost and efficiency.
Running 700mA.

Better off running CXB3070 AD bin at .7 amps than Vero 29 at .7 amps if you can get a good price for them. Difficult to recommend Veros when you can get 3070 BB bin from PLC for not much more, or 3590s from KB or Cutter for under $50.

To contradict myself a bit, I should mention recent tests by SupraSPL seem to indicate Vero at .7 amps, efficiency is similar BB at .7 and to running 3590s at 1.05 amps. It's from a limited test sample and conflicts with the datasheets, so take that for what it's worth. If accurate, the same efficiency from 3590 at 1.05 is worth considering with the price premium, but it does indicate Vero 29s aren't a bad budget choice at .7 amps. I would like to see more test before I call that one though. My experience with low current Vero has been very good, but nothing quantitative.

Rahz said:

You have to look at cost and efficiency to get a good par comparison. The CXB3590 CD bin at 2.1 amps (75 watts) is 160 LPW, slightly better than XPGBWT-H1-0000-00HE7 at .35 amps. At that current it would take over 75 XP-G2s to equal the cost/performance margin.

Click to expand...

Rahz said:

To contradict myself a bit, I should mention recent tests by SupraSPL seem to indicate Vero at .7 amps, efficiency is similar BB at .7 and to running 3590s at 1.05 amps. It's from a limited test sample and conflicts with the datasheets, so take that for what it's worth. If accurate, the same efficiency from 3590 at 1.05 is worth considering with the price premium, but it does indicate Vero 29s aren't a bad budget choice at .7 amps. I would like to see more test before I call that one though. My experience with low current Vero has been very good, but nothing quantitative.

Click to expand...

Yes have read the thread about how the Vero29 efficiency and Cree datasheets are contradictory.
Yeah COBs are getting way too expensive for very Little reason.
Thanks for the insight.

We are only using these cobs at 20% of their intended power. 35$ for 60-100w. or 45$ for 60-140w. The prices are fine truthfully. Lower is always better...but they are not too expensive in the grand scheme. Cree never once in their life has thought about either 3590 or 3070 under 60w. Just the way it is.
You should have been around before cobs if you think 35$ for 50w is too much. Hell, even the xpg2 youre talking about to get that kind of output/power would cost almost double the cxb. Rahz showed it well.

Greengenes707 said:

We are only using these cobs at 20% of their intended power. 35$ for 60-100w. or 45$ for 60-140w. The prices are fine truthfully. Lower is always better...but they are not too expensive in the grand scheme. Cree never once in their life has thought about either 3590 or 3070 under 60w. Just the way it is.
You should have been around before cobs if you think 35$ for 50w is too much. Hell, even the xpg2 youre talking about to get that kind of output/power would cost almost double the cxb. Rahz showed it well.

Click to expand...

In my currency a cxb3590 is about 100$.
I'm not too concerned with price. Was just also a point.
I'm well aware driving them lower increases efficiency.
Thank you for chiming in GG.
What's your opinion on the Vero29, as it seems SupraSPL is dong some serious tests indicating Cree is much more efficient as the datasheets. What do you make of the data?
Glad I got the run down from more educated on lighting.

Hi guys,

you mentioned that Supra have tested that the vero29 at 0.7a is the same effieciency as the 3070 BB on 0.7a, but can someone direct me to that post because i can't seem to find it for 3 days now.

And i'm also curios about the verdict of Greengeges about the vero29

Because i want to make an decision what to order cxa3070 or vero29 for a large area were electricity and airconditioning are not a problem. Want to build 2 layers of 1.25m height each to make maximum use of my square meters of grow space. I think i am mandatory to get passive cooling because i have less height,
what do you guys think.


greetz

Since electricity and a/c is not a problem but height is... https://www.rollitup.org/t/more-money-than-brains-a-water-cooled-cab-build.802108/

Hi redcrxsi,

Thanks for your reply! I have seen that post already but don't think that is necessary, that flowerchamber has an height of 80cm and i have about 40-45cm more.

I've read that a couple of people drive there cobs at 1.4a (50w) with 13-15cm space to the canopy. I also want to do that or maybe drive them even higher if that is possible.

I hope that someone can help me with my choice.

greetz

frica said:

Because people still buy those panels.

And CXB3590 @700mA vs 300 xp-G2 is not a very fair comparison either way since the CXB is much more efficient at that current so you'll need less watts and thus less cobs besides saving on your energy bill.

I'm comparing lumens because since they're Cree chips with similar colour temp they're likely going to have near identical colour spectrums.

Edit:The only reason why Cree cobs can be more expensive than SMD counter parts is probably because of the demand for cobs driving up the price. Manufacturing process of COBs is simpler than SMDs

You should also try looking at Bridgelux Vero chips.
They're a lot cheaper than Cree cobs but only slightly less efficient when driven hard.

Click to expand...

I should add atleast based on all the data sheet information, given bridgelux is just a reputable as cree and no more likely to skew the data the vero 29 Gen 3 can be more efficient then the cree CXB 3590 when driven lightly and overcooled like one would do with a diy light. i think the materials cree uses makes it more expensive and gives it slightly better performance when ran at high temps and current. it also probably has better lumen maintenance, but i don't think that matters at all given how fast the technology is progressing. Even if your cob didn't lose any of its performance over time it would still be cheaper to replace them then to to keep them because in less 30000 hours from now the performance and efficiency would have improved quite a bit.
This is were cobs have a real advantage over discrete diodes unless you have a reflow oven or use pre soldering leds on mpcb. In that respect the vero also has an advantage over the cxb, they were designed to be much simpler and quicker to replace and build a light with. they also conform to Zhaga book 3 standards so they are very compatible with many optics and heatsinks out there.

I'm using aavid synjet downlight coolers is was so easy to put together and the synjets are the perfect fit for leds they are just as reliable if not more because you can actually get the full 100000 hours out them where as leds like i stated before using them for any more then 50000 hours is just a waste of energy. the synjet coolers can also work passively without the synjets so even if they fail you only lose a bit of performance and not a total failure of your cobs

Cree high power is kinda expensive. Samsung's chips can be on par cost per umols/watt. Also they are somewhat more versatile than Cobs heat management wise. Optics are not as plentiful but with our new boards there are about 7 choices. SMD isn't dead...... Not by a long shot.