Well, I won't to too far out on a limb on the subject of dual coils because I still have MUCH to learn about them. I am NOT an EE and the tech information is complicated. I still hope an EE will jump in here and explain the FACTS.
Dual coils are very different from single coils, and not just because there are 2 coils.
According to this article:
How to Calculate Ohms in a Parallel Circuit | eHow.com
However, the incoming and outgoing amperage will always remain the same. The resistance only changes the amperage on the path the resistor is on.
I am assuming (possibly incorrectly) that the amps may be getting split between the coils. I think these coils are each actually higher ohms. I have seen dual coils that meter 2 ohms and others metering 1.5. I have also been "told" (in quotes because I have not yet confirmed the FACTS) that each coil is 3.2 ohms. I do not yet understand how these end up reading 1.5 or 2 ohms on a meter or Darwin. As you can see in the above linked article, the math gets a bit complex and this demonstrates some of the more complex aspects of ohms law (these parts are currently beyond my understanding - but I'll get it eventually, just need more time to study and I have been busy lately).
What APPEARS evident:
- Darwin reads these the same as a multi-meter (e.g. 1.5 or 2 ohms respectively) and supplies/regulates power accordingly. So, on a 2 ohms dual coil carto, my Darwin at max watts (12.7) will only push 5.2 volts and provide amps based on the 2 ohms reading.
- ProVari seems to wrestle with dual coils as well, especially the 1.5 ohms version and (depending on the voltage set) will often produce an Error code which temporarily shuts the device off = preventing vaping altogether (at least until voltage is dramatically lowered - possibly erroring even then {no longer have my ProVari so cannot do further testing})
- Multi-meters, so far, seem unable to distinguish between single coil resistance and dual coil resistance (if there IS a way to get the meters to make this distinction, I have yet to learn how to do it) but the dual coils certainly perform differently. Again, I am starting to think the path of the amps is a contributing factor and we have seen (in other devices using prism batts - tube style - that some batts have sufficient amps to accurately drive certain ohms/volts combos - like AW IMRs - and others provide insufficient amps for the ohms/volts combos resulting in under-load voltage drop-off). Until the dual coils came along, Darwin's batts have been able to accurately push and manage power for anything we throw at it. Darwin is STILL managing power correctly on these dual coils - just based on the ohms reading so it supplies power under the single coil model.
- *** THESE DUAL COILS PERFORM VERY NICELY ON UNREGULATED HIGH VOLTAGES (provided sufficient AMPS are available - in other words using something like the AW IMR batts in all mechanical devices like my GGTB)*** So, while these dual coil cartos are rated at low ohms, they certainly perform much more like higher ohms and seem very happy at HIGH votlage levels. I am using them on unregulated 6 volts and finding they perform very well at this level.
As for the question about the Colossal 801 Dual coil - I have one but have not gotten around to testing it yet. There seems to be some apparent criss-cross (over the last 2 pages in this discussion) about 801 cartos vs 801 dual coil colossal cartos. The basic 801 carto (as seen on NHaler site) is very similar (probably the same) to the Iken Fusion Boge JKY302 carto. This is a single coil carto that has the tube of 510 size (but a bit longer) and a flared out "collar" at the base to facilitate the 801 threading. These also have a different air intake than 801 style attys. 801 style attys have various air-intake holes thru the bottom of the connector (all downward facing).. Each model (801, BE112, 302, 4072) has a slightly different design to the size, shape and placement of the air-intake holes. These create variations in the airflow which most certainly impacts the overall vape experience. The JKY302 (801/fusion) cartos have 2 tiny pin-holes in the SIDES of the wider collar/flare-out for air-intake and appear to otherwise have only the center hole (center of positive connector/terminal) with none of the other 801 style air-intake holes found in the 801 series attys.
From visual inspection of the Colossal Dual Coil - the air-intake appears to be similar to the design of the JKY302 (801/fusion) but these have a tube size much closer to the 801 atty tube. And, of course, these have DUAL COILS so they are bound to function along similar lines to other dual coils. We have also seen that the various filler material inside cartos also impacts the flavor and the denseness with which that filler is packed/wrapped can impact the speed and efficiency of juice wicking to the coils.
So, while this post provides little conclusive factual information, I hope my observations are somehow helpful in your experiments as you compare. The bottom line on these matters, as with ALL vape gear combinations, is that the tech may be interesting to some and/or help with understanding WHY they are experiencing some of the differences. BUT, many may not care so much about the how(s) and why(s). With vaping, it is difficult to take anyone's word for what is "best" as all is so subjective and we each have our own "best/favorites". We can try different gear and combos (and take other peoples suggestions for stuff to try) but in the end - by trial and error - we have to find our OWN "best" for our own preferences. we each like what we like and the how(s) and/or why(s) may not matter so much.
I suggest you try what you can, when you can, and see what YOU like best - then HAPPY
I'm no longer a big fan of blastoid vapes. For the 2ohm I start at 6 and move up from there, depending on the juice and usually settle around 8.something. For comparison, I'm vaping my standard menthol juice in a dual coil reading 2.4 ohm at 6.7 and enjoying it...a lot! I've gone a lil past 10 with the 2.5's depending on the juice.
