The reason why the 3Mhz talk came up at some point was the fact that the US machine works at a specific area at a time. For example, let us say that you are trying to heat your forearm. It will NOT be possible. If you start moving your transducer in circular motion, slowly, and you start covering your whole forearm, by the time you are half way, your starting point will be cold again. Therefore the US is intended to be used in a small area.
For that same reason, Kyrpa had the following problem. In order to properly heat up the penis, he split the shaft in 2 sections. Then proceeded to heat up the bottom half, then he upper half. Still, by the time you are finishing heating up the upper half, the bottom half is already in the process of cooling down.
As a temporary fix, kyrpa was aiding himself with rice socks to not only keep the temperature up in the tissues but also to help them come up. That is when he said 'If the 3mhz heats up faster, then by the time I am finishing heating up the upper half of my penis, the bottom half will still be at target temperature.
Based on that Manko's acquired a 3Mhz machine which proved Kyrpa's logic.
However, Kyrpa came up with a workaround that is cheaper than buying a 3Mhz machine, and perhaps more efficient and versatile. The solution, buying a second US Pro transducer and use them both at the same time. One heating up the bottom half, the other heating up the upper half.
Both ways are equally beneficial, the whole purpose is to reach the target temperature and that is why they have been encouraging to measure temperature in the tissues constantly. Without proper temperature, there will be no results in terms of septum growth, and that is how so many people will claim this therapy to be useless and keep looking for the easy fix. You HAVE to measure temp and MAKE SURE you reach the already proven target temperatures.