Semi OT question

In pdf brochure on tuning forks that I've found, they state various
frequencies they consider important/beneficial.
I'm trying to figure out how did they come up with "pitch data"
and "tempo" values?
For instance: how does 172.06 Hz becomes "equivalent chromatical at
433,6 Hz" and then "tempo 80,6 /161,3 bpm"
Sorry if this is OT.

The actual pdf:
http://www.planetware.de/tone/The_CoOc_Tuning.pdf

--- In tuning@yahoogroups.com, "pasport197" <pasport197@y...> wrote:
> In pdf brochure on tuning forks that I've found, they state various
> frequencies they consider important/beneficial.
> I'm trying to figure out how did they come up with "pitch data"
> and "tempo" values?
> For instance: how does 172.06 Hz becomes "equivalent chromatical
at
> 433,6 Hz" and then "tempo 80,6 /161,3 bpm"
> Sorry if this is OT.

A frequency of 172.06 Hz, transposed down 6 octaves, gives an
oscillation frequency of 161.3 beats per minute. You just multiply by
60 to convert from "per minute" to "per second" units, and divide by
2^6. Another octave down, and you get 80.6.

Now if you consider your 172.06 Hz to be an "F" and tune a 12-tone
equal temperament system to that, you'll get a "A" of 433.56 Hz,
which rounds to 433.6 Hz. Just multiply 172.06 by 2^(16/12).

Thanks!
It all looks so easy now :)
>
> A frequency of 172.06 Hz, transposed down 6 octaves, gives an
> oscillation frequency of 161.3 beats per minute. You just multiply
by
> 60 to convert from "per minute" to "per second" units, and divide
by
> 2^6. Another octave down, and you get 80.6.
>
> Now if you consider your 172.06 Hz to be an "F" and tune a 12-tone
> equal temperament system to that, you'll get a "A" of 433.56 Hz,
> which rounds to 433.6 Hz. Just multiply 172.06 by 2^(16/12).