Are you insane? What leads you to believe they're the same as the Dyns? Just because they have a similar looking cone and dustcap?
They are nothing alike. The Hi-Vi is just a cheap ripoff of the Dyn
IMO.
Let's look at some of the differences:
The Hi-Vi is 8 ohm, Dyn is 4 ohm
The Hi-Vi is shielded.
Hi-Vi has a lower Fs due to the heavier cone (higher Mms)
Higher Qts, Qes, lower Qms on the Dyn
Smaller Vas on the Dyn
Dyn has copper in the motor, unknown if the Hi-Vi does, which it should at the prices they cost, especially for being made in China... I'm surprised they don't cost $7.40 as opposed to $74