Seoul P4 vs Cree XR-E

Hello Everyone,

Sorry if this was already hashed out--I searched, to no avail. Just wondering if anyone could list (or direct me to a thread) the major differences between the Seoul emitter and the Cree. Characterisics such as tint, dome hardness (which I already heard about, but might be useful to others), ability to deal with heat, bins and wattage, etc. Thanks in advance!!!

Use the google CPF search at the top of each page and google Seoul P4, read about it, then google Cree XR-E. During this search you will also probably find a comparison. Tons of info on both of these, and you can compare info.

Bill

duh! search them both? i don't mean to be rude but that's not very helpful. i would like a similar answer and i think this would be a cool thread. what is the difference? is the seoul p4 a little more efficent and can handle extra ma? i think i remember hearing that. but i also hear they are "cousins" and very similiar. can anyone compare the two for us noobs?

here you go, i even cut the crust off for you:

both use the same die, the part that makes the light. lumileds has patented the best methods of applying the phosphor layer that converts the blue light into white and so the methods cree and seoul have used are not as uniform and this is seen in tint variations throughout the radiation pattern. "white-wall hunters" can be displeased by this.

the cree seems to be the more durable package. gummy bear dome aside, the seoul has shown a tendency to shift in tint over a period of time. as to output, well, the jury seems to be out. in one test seoul's u bin (higher output than their t bin) was one of the brightest as well as one of the dimmest with all t bins falling somewhere inbetween. seoul seems to still be tweaking the recipe and making un-announced changes mid-stream.

you can send a dollar to my paypal.

They are just as good for each other, the seoul P4 emitter is easier to mount,

Here's a nice graph of the lumens per watt vs. current for the Cree and P4, though as ginaz said the output can vary from LED to LED even within the same bin.

https://www.candlepowerforums.com/threads/152094

The P4 is MUCH easier to solder and for the most part works with reflectors, heatsinks, and optics designed for the Luxeon I, III, V LEDs as it is almost identical in shape (round) and size, except the P4 sits a little bit lower than the Luxeon. The bad things about the P4 would be the fact that the bottom is electrically connected to the anode (+ termination) so you have to be sure to electrically isolate it from your heatsink, and the P4 also has a gummy / sticky dome that is a dust magnet. It's a little hazy too, not nearly as clear as the dome on a Cree or Luxeon.

The Cree is a completely different footprint (rectagular instead of round), but, the Cree has a nice dome and the bottom of the Cree is electrically isolated. The Cree, in general, isn't as bright as the SSC P4, but it is very well packaged. Problem is, it dissipates heat so well that if you use AS or AS epoxy to connect it to your heatsink BEFORE you solder the wires to it...well, when you do try to solder you'll find it to be almost impossible as the Cree will suck the heat away from the solder pad and into the heatsink and you'll never get the solder to melt. One more thing; the + and - solder connectors on the Cree are on both top and bottom, so you have to either clip the corners off of the Cree (where the traces run from top to bottom), or electrically isolate the entire LED. I prefer clipping the corners...

It seems that Philips Luxeon is back in the game now too with their GenX LED- you guys seen this thread?

https://www.candlepowerforums.com/threads/150005

ghadlock said:

The Cree, in general, isn't as bright as the SSC P4https://www.candlepowerforums.com/threads/150005

Click to expand...

That may no longer be the case now we're finally getting our hands on Q bin Crees, as the P4 bin was quite close

Good point, Chris_m - I got an email from Cutter.AU two days ago stating that they'd shipped their first 1000 Q2 bin XR-Es. I actually placed an order for some XR-Es from Cutter about 2 months ago and they never came....I don't know if the order didn't get processed (they obviously got my email adddress) or if I have some Q2s on the way via slow boat from Austrailia so we'll see. One thing that I didn't mention in my previous post, and I haven't seen any test results to document...

The brightness diminishes as the temperature of the LED increases. That said, the Cree does a great job of pulling heat away from the LED with the larger package and great thermal conductivity so at longer run times it is easier to keep a Cree cooler than an SSC P4 which does impact the brightness. That fact, coupled with the new Q2 bin XR-Es certainly may give Cree XR-E the lead for high power applications. I can't wait to see some of the new Q2 based mods!

Thanks for all the info everyone! Cant wait to see the Q bins

I didn't see it mentioned -- the Seoul has a radiation pattern that's similar to the Luxeon, so it usually works well in reflectors originally designed for a Luxeon (provided that you can move the LED about 0.030" to compensate for the different die height). The pattern of the Cree is narrower, so it usually doesn't focus as well when used as a direct Luxeon replacement. Flashlights which use it generally have a deeper reflector than ones using a Luxeon or Seoul, because of its different radiation pattern.

One other note about the Seoul -- on every star I've encountered, the LED mounting pad is electrically isolated, so there's no need to insulate the LED from the pad in spite of the internal anode connection when mounting on a star. You do, of course, have to insulate it when mounting to a conductive pad that's connected to something other than the positive LED supply voltage -- which is virtually always the case if there's no star.

c_c

Having read the info above, am I correct in thinking that the STARS of both Cree or Seoul are electrically isolated? Ie i can AA them to the heatsink without worrying about shorts etc?
I am looking at them for home lighting, so thanks to the info above, I think uncovered Seouls would be out, on the account of dust sticking to them.

I don't know if it just me but on the Seoul, when I run over 1 amp on it, it turn mad blue and very dim and when I lower it at 1 amp or below, then it white again.
On the Crees, I run it at 2 amp, it's very bright.

glockboy said:

I don't know if it just me but on the Seoul, when I run over 1 amp on it, it turn mad blue and very dim and when I lower it at 1 amp or below, then it white again.
On the Crees, I run it at 2 amp, it's very bright.

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2A? wow, didn't know they can take 2A without frying, good to know!

Mash said:

Having read the info above, am I correct in thinking that the STARS of both Cree or Seoul are electrically isolated? Ie i can AA them to the heatsink without worrying about shorts etc?
I am looking at them for home lighting, so thanks to the info above, I think uncovered Seouls would be out, on the account of dust sticking to them.

Click to expand...

Every one I've seen is isolated. But I still check each time -- who knows what variations there might be out there.

c_c

Curious_character said:

I didn't see it mentioned -- the Seoul has a radiation pattern that's similar to the Luxeon, so it usually works well in reflectors originally designed for a Luxeon (provided that you can move the LED about 0.030" to compensate for the different die height). The pattern of the Cree is narrower, so it usually doesn't focus as well when used as a direct Luxeon replacement. Flashlights which use it generally have a deeper reflector than ones using a Luxeon or Seoul, because of its different radiation pattern.

One other note about the Seoul -- on every star I've encountered, the LED mounting pad is electrically isolated, so there's no need to insulate the LED from the pad in spite of the internal anode connection when mounting on a star. You do, of course, have to insulate it when mounting to a conductive pad that's connected to something other than the positive LED supply voltage -- which is virtually always the case if there's no star.

c_c

Click to expand...

Are you only talking about Lux I and Lux III, becuase the Lux V seems to have a completely different radiation pattern from what I have seen. I'm still a NewB but I do believe that that a Lux V does not have the radiation pattern that you are talking about? Feel free to unleash on me as I am only going by personal experience and am not certain of what I am talking about.

I'm sure by radiation pattern he's describing the way the photons of light "radiate" off the surface of the dome and does not refer to the radiation hazard pattern seen here: