The frequency you want the dial on is 432hz not 440.
Add 7.83hz to that. These work well with good headphones or sound system...
https://www.youtube.com/watch?v=E5Ppl49Lg1w
https://www.youtube.com/watch?v=AZJK36dxvxI
https://www.youtube.com/watch?v=BJ9pkEiI4OQ
https://www.youtube.com/watch?v=9wYwQFp2mfU