Could someone please plot in some specific High Shelf and High Shelf Filter points for me?

[NoiseNinja]

I use following shelving filters in a TC Electronic Sub'N'Up Mini custom toneprint :

High Shelf Filter set to : 8kHz -20dB with a 12dB/Oct slope

And another High Shelf Filter set to : 12.5kHz -20dB with a 9dB/Oct slope

And then finally a Low Shelf Filter set to : 4.5kHz +2dB with a 9/dB Oct slope

And would like to know how they look on a graph (X axis=Hz/Y axis=dB) to get a more precise idea of what they do exactly, but as it turns out the VST equalizer I use in my DAW doesn't let one dial in the slope, which instead is controlled by bandwidth, which just adds up to nonsense number wise translated to a slope vallue.

So I would like to ask if anyone with a VST equalizer that allows you to actually set the slope value would please plot these 3 filters into it for me, take screen shots of the result of each filter separately, and post it in this thread?

I need a separate graph for each of the 3 filters, without any of the other filters interfering.

 

[Frank Tuesday]

How does TC Sub'N'Up determine the frequency? Cut-off, Center or Corner frequency?

 

[silky smoove]

Yeah, I can do that. I’m going to my studio in a few hours and will grab some screenshots if no one else has gotten to it before me.

 

[NoiseNinja]

How does TC Sub'N'Up determine the frequency? Cut-off, Center or Corner frequency?

-3dB corner I assume, isn't that the standard?

Yeah, I can do that. I’m going to my studio in a few hours and will grab some screenshots if no one else has gotten to it before me.

Thank you so much.

 

[silky smoove]

Your original request leaves out the Q value, so there's a range of possible results based on Q. I've provided extremes on either end as well as more common Q values of 0.7, 1.0 and 2.0 in the middle. The actual plot of your device will vary somewhere along the provided spectrums, which as you can see ends up being pretty drastic based on Q.

Here's the 8khz filter. Again, the frequency (8khz), amount of cut (-20db) and slope (12db/oct) all remain the same and only the Q changes. This EQ defaults to a Q of 1.0 on all bands, but some of my other EQs default to 0.7. I suspect somewhere in that range would be a common point for many devices.

For the next two filters things get a little more complicated. I don't have another EQ that will allow a filter slope (i.e. db/oct) to be applied to a high/low shelf. A filter slope is typically seen on LPF/HPF bands. I'm sure there's a way to mathematically correlate the two ideas (i.e. bandwidth versus slope) but I've never done it. Since this is my only EQ with that functionality I'm limited to what it has available, and unfortunately a 9db/oct slope is not an option. It provides 6db/oct and 12db/oct options. Further, when you set it to 6db/oct the Q control grays out and becomes a fixed value, which is why all of the EQs show the same thing when set to 6db/oct.

Here's the 12.5khz filter (6db/oct first, and 12db/oct second):

Here's the 4.5khz filter (6db/oct first, and 12db/oct second):

Just to reiterate; I would guess that your device uses a Q value somewhere between 0.7 and 1.5. If you look at the three middle plots and take an average you'll likely be pretty close, but that's entirely speculation on my part. Hopefully this helps.

 

[NoiseNinja]

Your original request leaves out the Q value, so there's a range of possible results based on Q. I've provided extremes on either end as well as more common Q values of 0.7, 1.0 and 2.0 in the middle. The actual plot of your device will vary somewhere along the provided spectrums, which as you can see ends up being pretty drastic based on Q.

Here's the 8khz filter. Again, the frequency (8khz), amount of cut (-20db) and slope (12db/oct) all remain the same and only the Q changes. This EQ defaults to a Q of 1.0 on all bands, but some of my other EQs default to 0.7. I suspect somewhere in that range would be a common point for many devices.
View attachment 4429270

For the next two filters things get a little more complicated. I don't have another EQ that will allow a filter slope (i.e. db/oct) to be applied to a high/low shelf. A filter slope is typically seen on LPF/HPF bands. I'm sure there's a way to mathematically correlate the two ideas (i.e. bandwidth versus slope) but I've never done it. Since this is my only EQ with that functionality I'm limited to what it has available, and unfortunately a 9db/oct slope is not an option. It provides 6db/oct and 12db/oct options. Further, when you set it to 6db/oct the Q control grays out and becomes a fixed value, which is why all of the EQs show the same thing when set to 6db/oct.

Here's the 12.5khz filter (6db/oct first, and 12db/oct second):
View attachment 4429268
View attachment 4429269

Here's the 4.5khz filter (6db/oct first, and 12db/oct second):
View attachment 4429267
View attachment 4429266


Just to reiterate; I would guess that your device uses a Q value somewhere between 0.7 and 1.5. If you look at the three middle plots and take an average you'll likely be pretty close, but that's entirely speculation on my part. Hopefully this helps.

Thanks a lot.

 

[Frank Tuesday]

-3dB corner I assume, isn't that the standard?

That is most commonly used, but for shelving, Q is most commonly used rather than dB/octave. Shelving eq defined with db/Oct is counterintuitive. To understand why, it's important to understand how each set of adjustments is made. A Q value will keep the same corner frequencies no matter the amount of gain, or in other words keeps the bandwidth constant. This means the slope of the filter will change based on the gain to keep the bandwidth constant. But if you define the curve using dB/Oct, the slope stays constant, which means the bandwidth changes when you change the gain. If you increase the magnitude of gain, the bandwidth increases.

If your pedal is in fact using dB/Oct, the only way to know for sure what it is actually doing is to send some white noise through it and compare the frequency response with the pedal on and off. I don't know of any plugin that uses dB/Oct for shelving EQ. It may exist, but I haven't found it yet.

 

[silky smoove]

I don't know of any plugin that uses dB/Oct for shelving EQ. It may exist, but I haven't found it yet.

Check my post earlier in the thread which shows screenshots from Crave DSP’s EQ.