Because the 5200 was built to be the strongest motor on the planet when it was released. The 5400 still has a very strong motor and generally needs a small box and will still play lower than 99% of subs on the market, and does it with a flat response when tuned low. You already messed with the 5200 and saw what it's frequency response looked like. Go look up the 5400's specs and you'll see what I mean. It can play very low, very flat in small boxes. The 5400 also has copper in the motor to lower inductance based distortion. The inductance of the 5400 is less than 1/3 the inductance of the 5200, which means it can play higher frequencies with less distortion. If you like to cross your subs high this is a great thing and really lowers distortion. Lastly, the 5400 fits the LMS coil which greatly lowers BL related distortion. If your into SQ the 5400 crushes the 5200 in every way. The 5200 is really more of an SPL driver when used in a car app, unless you put it into a sealed box. It has more motor than you need for any kind of a SQ app ported in a car and doesn't have the fancier distortion lowering components (LMS Coil and shorting rings) that you find a 5400.r
Also about the 2x the output on the same power. If you look at how subwoofer's actually work, you'll see that isn't the case. The stronger motor does make it more "effecient", but at the expense of low end output. What you end up with is a driver with high effeciency, that begins to fall slowly, at a high frequency. The lower strength 5400 motor does the opposite, starts weaker, but decreases very little as it goes lower until eventually falling very rapidly. In a sealed box for each, you'd need around 2x the box size for the 5400, but still a small box. However, when you do this the effeciency difference will all be above 100hz on paper anyway, where you normally use a sub in a car below that, they will be very close. Then when you factor in indutance, you realize they are probably in truth pretty close higher up, but the 5400 has less distortion AND more capability down low due to the higher xmax. Look at these graphs and they show what I mean.
Here is 5200, you can see it's 3b down by 113hz! However it falls very slowly so that you still have good output through the bass region.
Here is the 5400, you can see it's lowered output, especially above 100hz and going higher, but again I don't beleive this factors in inductance, nor will it show how they sound that high, the 5400 will be cleaner up there if you used it that high. You can see how it falls very slowly as you go lower in frequency until 20hz where it finally begins to really drop off, still more flat overall, again this is in 2x the box size, but the 5200 has such a strong motor, box size hardly makes a difference it's ALL motor. The extra motor force on the 5200 really only does 2 things. 1. You can use it in a retard small box. 2. It's useless in a ported box unless you want pure SPL. 5400 is a little more well balanced. It does well sealed or ported more or less and still needs a small box, just not AS small.
As far as tantric goes, I have no idea. They stole the baskets off of TC sounds, whether they stole a motor too and improved upon it IDK (I'm half joking here). Only way to know for sure would be to get them both on a klippel, the 5200 has been put on one and it's specs are pretty well known. The Tantric is a strong motor I'm sure as it's designed as an SPL driver, stronger, who knows? To find actual motor strength the formula is BL^2/RE. The 5200 is 410 Netwons/watt, which is pretty beefy. To put it into perspective the DDZ and Warden which have both been touted as the strongest motor ever, by DD nuthuggers and Incriminator Audio itself, only clocked in at 310ish for both units when Jacob actually tested them.. Even my 21 which is a neo magnet with a 6inch coil is only around 300.. (although it's NOT an SPL driver per say, big coils like that just make for strong *** motor force without a lot of work lol)
