Neither a Dripper nor a Genesis

Theorem by Wismec properly holds is name, an hybrid that enters in no current atomizer category.

A Dripper without be one, formally, because of its small liquid tank located below. Not completely a Genesis even if it bothers the top coil system generating a warm vapor.

This type of atomizer is a priori not my cup of tea, I am not looking for the volume of vapor but rather the rendering of flavors, what drives me to refill all the time. But I admit that I was puzzled by this new bobbin-like coil in stainless steel. It offers a huge surface of contact between the cotton and the heating part and keeps a good airing to accept high power supply.

This Therom by Wismec will probably be best appreciated by direct vaping lovers and by those who prefer big clouds. But, to my surprise, it can also fit to a tiny 30/40 W hardware to render a maximum of flavor to your favourite liquids.

The people who thought about this design are not beginners since it is the fact of SMM and Jaybo. You either love or hate, but it works pretty well and, on top of its qualities, it does not leak.

Wismec does not go in for half-measures with its powerful boxes accepting three batteries and its overfed kits.

The sales target of the Theorem is the expert vaper or the insane cloud chaser. But if you feel like tasting, for a reasonable price, a vape style that becomes financially reachable, this atomizer can represent a good choice because of easy operation and reliability of Notch coils.

Technical characteristics

  • Thread: 510
  • Coil: 4-pole type velocity (one bridge)
  • Capacity: max 2 ml
  • Simple coil or dual coil of any type
  • Length (with tip): 46.25 mm
  • Diameter: 22 mm
  • Weight: 29 g (fully equipped)
  • Drip-tip: insulated in pyrex
  • 2 spare tanks, one has a metal cover
  • Spares: 2 screws and 4 O-rings, a key (1.25 mm) to (un)screw the bolts
  • One single or dual airflow, depending on the rim
  • One airflow ring with three openings

A design for direct vaping and a reactive Notch coil that performs very well in temp control mode

I open the box and seize this tiny Theorem, the kit seems complete with two pyrex tanks among which one is covered by metal to high the inside, if you prefer. When vaping, the inside is less and less palatable but the advantage is that you can easily see when the cotton is drying.

The base plate offers a huge potential for mounting home-made coils instead of the Notch coil (provided). One can easily mount in dual coil, diagonally.

The airflow system is a bit painful to adjust because it consists in a crown that fits on the top cap that can loose its adjustment when screwing it. But the clever refilling operation by removing both top cap and airflow prevents it from loosing adjustment.

The mounting plate diameter is comfortable for setting single coils, and dual coils can easily be screwed on the bolts. Nevertheless, the finish is a bit lousy, showing manufacturing marks. I am also doubtful regarding the quality of the O-rings, and their surprising color would make me change them very quickly. They are necessary for maintaining the ensemble and to ensure no leakage.

The drip-tip is insulated but a bit short, in my opinion. Chain vaping in the temp control mode can lead to heating the top cap that you can inadvertently touch with the lips.

In fine, let’s have a look at the openings for the cotton at the bottom of the tank. They are large but located adequately for the size of a Notch coil. Due to this large diameter, it is required to use a lot of cotton and to ensure the tips are long enough to dip into the liquid. On my specimen, I cut cotton a little bit shorter to leave more space to the liquid in order to increase the autonomy of the half-tank. Believe me, if you do not do that, you will chain two tenths of puffs before refilling.

A ready-built stainless steel Notch coil: reactive, tolerant but fragile

The ready-built is also pre-mounted, which makes the first approach of the atomizer very easy to start vaping right away. Be aware that the cotton is of a quite bad quality and that it need a bit of rinsing.

I experienced not leakage but I confess I questioned the refilling procedure. I wrongly thought that bathing the coil with liquid was enough to refill the tank located below. But it is only by removing the whole (drip-tip + cap + airflow) that is achieved a correct refill. To remove it, remember to seize the pyrex tank because the tank is interlocked with the mounting base. An opening located under the black part allows refilling but I could not introduce more than 1.5 ml of liquid.

Beware also to the Notch coil legs, they are fragile because they are welded on the cylinder and can break easily during handling of the ensemble. Be very careful. The coil mounted on my specimen was of 0.23 Ω and accepted the power, especially in the temp control mode. I was surprised by the very pleasant rendering of flavors at high power but I also enjoyed vaping in the lower range, around 30 W. I noticed no sour diesel effects like sometimes happen with Clapton coils or other Mecas. Reactivity is full.

Finally, be attentive to moisture the cotton if you are in watt/power mode otherwise you might feel a “dry hit” when running out of liquid. It won’t happen in temp control mode, which is my recommendation.

A hybrid Theorem with a low autonomy that complies with pre-built and home-made coils

This top coil is of a new type since it offers a semi rebuildable solution. It is a come back for the pre-built Notch coils, what I dislike. I have been purchasing any coil for about 2 years, and you?

For whomever is not shocked by purchasing coils, Notch coil offers a rapid and simple solution where you only have to fit the cotton inside, like KangerTech and its coils ready for use. The atomizer will remain for occasional except if you accept to refill it all the time, which is crippling to me.

I am not the target-user for such atomizers and their coil, althought innovative, does not bring enough satisfaction or novelty to make me quit my habits for this one.

The added value of the Notch coil did not convince me at all since home-made coils are close to render the same result and are much more robust.

Aerial vaping, powerful and satisfactorily rendering flavors, which is a performance

If you enjoy thick and abundant vapor, stop there, you’re at the right place, this stuff is easy to use and of high efficiency. The equiation nevertheless incudes two unknowns because the Theorem can also become a sort of enhanced Dripper by using the dual airflow ring that allows air supply from the sides and from the top.

To finish, its versatility is achieved by a fourfold connectivity that is appreciated by expert vapers or other subohm and power vaping lovers. There exist passionate users, and Theorem is addressed to those ones.

These practices are, in my opinion, limited by the cooling of the device that has not been optimized, in particular at the levels of the drip-tip and to top cap.

In summary

The “+”:

  • Innovative pre-built Notch coil
  • Excellent for power vaping
  • Singular tank
  • 4 connection bolts for easy mounting of dual coil
  • Large mounting plate
  • Double Airflow, very aerial type
  • Ultra light
  • Price justified

The “-“:

  • Low autonomy
  • Notch coil’s legs too fragile
  • Bad heat dissipation
  • Airflow hard to adjust
  • Short Drip-tip
  • O-ring’s colour surprising
  • Disassembly is tricky
  • Finition is lousy
  • Drip-tip not included
  • Insane consumption


Rating 3.3/5. Special mention for the coil, if you’re not much of a handyman or woman. The Theorem by Wismec launches the new Notch coil that only half convinced me because of weaknesses at the level of the welded legs. It nevertheless offers an easy going concept for the non-experts, and therein lies the dilemma because, in my opinion, top-coil atomizers only address to experts.

Value for money
Vape quality
Manufacturing quality
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Reviewer for the past 3 years, I've tried most of the popular products available on the market. My conclusion about the best vaporizer ? The one that simply fits your need and makes you forget tobacco.