Hi Vdi,
this was posted in the mox lite group buy. I cannot recall who should get the credit.
Ignore all the other sheets, unless you need some other corrections, just use moxlite meantime which I have changed to your 2500Hz filter frequency.
You can also go to ESP and download his java L-R calculator.
this was posted in the mox lite group buy. I cannot recall who should get the credit.
Ignore all the other sheets, unless you need some other corrections, just use moxlite meantime which I have changed to your 2500Hz filter frequency.
You can also go to ESP and download his java L-R calculator.
Hi Vdi,
the spreadsheet designer has allowed the option for equal resistor values or unmatched resistors.
Notice that in all three calculators you set the Q before choosing the Rs or Cs. I have appended the three common Qs used in Butterworth and Linkwitz Reilly.
The ratio between the two caps and the ratio between the two resistors determines the Q of the filter. When these are 1:1 and 1:2 you get Butterworth Q (1/root2).
If you want a different Q then you can stagger the capacitors or stagger the resistors or do both.
I find the variable resistor less easy to manipulate. I find it very difficult to choose a Q and then select Rs and Cs to give that Q with either calculator. I would use equal value S&K for this. That was my point in the earlier posting.
Try to set up 4 pole Butterworth with Q=0.54 for first stage and then repeat the calculation using Q=1.3 for the second stage and you will find that selecting Rs and Cs is very laborious. There are better methods than this calulator. But for Q=1/root2 it works just fine. Which is where the unity gain S&K excells.
the spreadsheet designer has allowed the option for equal resistor values or unmatched resistors.
Notice that in all three calculators you set the Q before choosing the Rs or Cs. I have appended the three common Qs used in Butterworth and Linkwitz Reilly.
The ratio between the two caps and the ratio between the two resistors determines the Q of the filter. When these are 1:1 and 1:2 you get Butterworth Q (1/root2).
If you want a different Q then you can stagger the capacitors or stagger the resistors or do both.
I find the variable resistor less easy to manipulate. I find it very difficult to choose a Q and then select Rs and Cs to give that Q with either calculator. I would use equal value S&K for this. That was my point in the earlier posting.
Try to set up 4 pole Butterworth with Q=0.54 for first stage and then repeat the calculation using Q=1.3 for the second stage and you will find that selecting Rs and Cs is very laborious. There are better methods than this calulator. But for Q=1/root2 it works just fine. Which is where the unity gain S&K excells.
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