K402/K-691 EQ SETTINGS

[Chief bonehead]

46 minutes ago, mikebse2a3 said:

 

@Chief bonehead  for clarity are these the settings using the Xilica or EV DX38

It doesn’t matter. I think the xilica describes shelf filters a little differently than what I have listed. 

[mikebse2a3]

1 hour ago, Chief bonehead said:

It doesn’t matter. I think the xilica describes shelf filters a little differently than what I have listed. 

 

It’s been awhile since I used the EV DX38 and EV DC-One versus the Xilica XD4080 program simulators but I definitely had to change some of the shelf filter’s parameters in the Xilica to achieve identical projected output responses from the Xilica when compared with the EV DX38 or EV DC-One.

 

 

 

Note: Both EV units behave identical with the same parameters settings which I simulated and verified with output measurements several years ago.

 

miketn🙂

 

 

 

 

 

[babadono]

"it doesn't matter" yea its the same but different

@mikebse2a3 can you expound more on what the differences with the shelving filters are /were? Or do you not recall the subtleties?

[Edgar]

2 hours ago, babadono said:

can you expound more on what the differences with the shelving filters are /were? Or do you not recall the subtleties?

 

It may come down to definitions of parameters. If you are deriving the shelf filters using the RB-J Cookbook, then the critical frequency is the frequency at the midpoint of the boost or cut. RB-J also defines a "shelf slope S" parameter that is usually set to 1, but doesn't have to be. 

 

By comparison, when I implemented shelf filters in firmware, I defined the critical frequency as the frequency at which the piecewise linear Bode Plot would break from 0 dB (which corresponds to the ±3dB frequency for large boost or cut), which I think is what most people expect. I also avoided confusion with the "shelf slope" parameter by providing a choice of either fixed 6dB/octave or fixed 12dB/octave.

 

Both methods are correct. You just have to know which one you're dealing with. 

[mikebse2a3]

3 hours ago, babadono said:

"it doesn't matter" yea its the same but different

@mikebse2a3 can you expound more on what the differences with the shelving filters are /were? Or do you not recall the subtleties?

 

Let me see if I can find my notes from about 2 1/2 years ago when I was researching it. 

 

I remember when using the Xilica I selected the Octave/Q set point and then having to Change the Frequency set point depending on the Amplitude set point to achieve the matching simulated output with the Xilica that matched the EV Shelf filter settings simulated output response.

 

If any one wants to play with this just download the editor/simulation programs for the EV DX38 and EV DC-One and program them using Roy’s Settings and this becomes your reference output curves. Then do the same in the Xilica editor/simulation compare them with the Xilica results and then start tweaking the Shelf Filter’s parameters in the Xilica until the output curve results match the EV reference curves.

 

miketn

 

 

[mikebse2a3]

This is a note I made of variable multiplication factors I used (I developed these through trial and error) that allowed me to calculate the new Xilica Lo-Shelf Frequency Set Point based on Amplitude Set Point of the filter that gave me results very close to the EV Units Lo-Shelf performance.

 

Note: I found the Xilica Lo-Shelf 1.80 Oct(Q=0.751) set-point best to equal the EV 12db Slope set-point and then adjust Frequency Set-point based on Amplitude Set-point and my multiplication factors listed below.

 

For example:  EV-DC One.                    Xilica XD4080

                        Lo-Shelf                         Lo-Shelf

                        -10db                              -10db

                        5400Hz.                         4200Hz (5400Hz x .7775 = 4198.5Hz)

                        12db Slope.                    1.80 (Oct) / Q= 0.751)

 

                        EV-DC One                     Xilica XD4080

                        Lo-Shelf                          Lo-Shelf

                        -1db                                 -1db

                        2500Hz                           2500Hz (2500HZ X 1.0 = 2500Hz)

                        12db Slope                      1.80 (Oct) / Q= 0.751)

 

Again what I basically found was at -1db Amplitude of the Xilica Set-point no Frequency Change was needed but as the Xilica Lo-Shelf Filter Amplitude Set-point was increased the Frequency Set-point needed to be adjusted lower to match the EV Lo-Shelf Filter.        

 

miketn

 

 

 

[babadono]

Thanks @mikebse2a3