Jump to content

Logarithmic Expression Pedal Control for Low Pass Filter


Meiannatee
 Share

Recommended Posts

I'm building a synth-like patch, with the built-in Helix expression pedal controlling the high-cut (low-pass) frequency of the Low and High Cut block.

 

With the pedal min at 1kHz and max at 11kHz, there's not enough fine control at the low end. If I drop the max range of the pedal, I won't have enough highs with the pedal fully down. If there's an option for a logarithmic sweep like in the Volume block, that will solve the problem. Unfortunately, I can't figure out how to do that. Care to help?

 

And yes, I've tried using the Wah blocks, but all of them have a very pronounced resonance peak at the cut-off frequency of which there's no control to cut out.

 

Side problem: Is there a low-pass filter block that goes lower than 1kHz?

Link to comment
Share on other sites

On 7/23/2021 at 7:28 AM, Meiannatee said:

I'm building a synth-like patch, with the built-in Helix expression pedal controlling the high-cut (low-pass) frequency of the Low and High Cut block.

 

With the pedal min at 1kHz and max at 11kHz, there's not enough fine control at the low end. If I drop the max range of the pedal, I won't have enough highs with the pedal fully down. If there's an option for a logarithmic sweep like in the Volume block, that will solve the problem. Unfortunately, I can't figure out how to do that. Care to help?

 

And yes, I've tried using the Wah blocks, but all of them have a very pronounced resonance peak at the cut-off frequency of which there's no control to cut out.

 

Side problem: Is there a low-pass filter block that goes lower than 1kHz?

 

As far as I know there are no EQ blocks on the Helix that have a low-pass(high cut) filter that goes below 1khz. The only thing I can think of that might work is somehow using the 'Split Crossover', which goes down to 25Hz, to maybe rig something up to your liking.

 

I guess another approach would be to get tricky and have the expression pedal work two or more parameters simultaneously on the Parametric EQ. The 'Tilt EQ' also has a 'Center Freq' parameter that can be set as low as 100Hz.

 

Don't know of any way to explicitly set the curve to logarithmic for any block other than 'Volume'. 

 

Note: The Helix EQs do have the high pass(low cut) filter available down to 20Hz but you were probably already aware of that.

Link to comment
Share on other sites

Look in the Filter Section, under Legacy, and try the Q Filter.

Im not sure the frequency it goes down too, but its going to work a lot better than a wah or eq.

The expression pedal has plenty of control in the lower ranges when used on Freq value with this effect.

 

  • Upvote 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...