Spline EQ - how to create a steep HPF?

Official support for: photosounder.com
User avatar
Novalis
KVRist
328 posts since 18 Sep, 2013

Post Wed Aug 27, 2014 5:35 am

Hi guys,

I'm experimenting with Spline EQ, and I have to say, I've never heard an EQ that transparent so far :)
However, it surely needs a bit time to get used to the handling.

Could somebody please help me, as to how I can create a steep hi-pass filter (low cut)?

This is what I've got so far:

Image

I set one band at 20 Hz, dropped the gain drastically, and set the next band at 30 Hz.
However, I cannot get the slope to get steeper, whatever I do with the gain or slope at either bands.
(The real curve is shown with the dotted lines, as far as I understand.)
I don't like to have a resonance bump, just a straight low-cut.

Any help much appreciated :)

User avatar
Yeager
KVRian
1111 posts since 28 Jun, 2005

Re: Spline EQ - how to create a steep HPF?

Post Wed Aug 27, 2014 11:21 am

Up the Resolution to 16

User avatar
Novalis
KVRist
328 posts since 18 Sep, 2013

Re: Spline EQ - how to create a steep HPF?

Post Wed Aug 27, 2014 4:07 pm

Ok, and then?

User avatar
Turello
KVRAF
3149 posts since 6 Jul, 2012 from Sick-cily

Re: Spline EQ - how to create a steep HPF?

Post Wed Aug 27, 2014 4:15 pm

I ever wonder to myself the same question million times... Yeager, and Then? o.O

User avatar
Novalis
KVRist
328 posts since 18 Sep, 2013

Re: Spline EQ - how to create a steep HPF?

Post Wed Aug 27, 2014 4:51 pm

It's always the question in life - what to do next? :hihi:

User avatar
valerian_777
Banned
1182 posts since 24 Jun, 2014 from Giza Plateau

Re: Spline EQ - how to create a steep HPF?

Post Wed Aug 27, 2014 9:05 pm

Sure there is a HPF in the presets.
║▌║█║▌│║▌║▌█

User avatar
Novalis
KVRist
328 posts since 18 Sep, 2013

Re: Spline EQ - how to create a steep HPF?

Post Thu Aug 28, 2014 4:19 am

I use the free version.

Is the one in the presets steeper than the one on my screenshot?

User avatar
Novalis
KVRist
328 posts since 18 Sep, 2013

Re: Spline EQ - how to create a steep HPF?

Post Thu Aug 28, 2014 6:45 am

I was looking for this thread now for 10 minutes...
looks like somebody moved it.

Would be nice if one would be notified somehow if a thread got moved, for whatever reason.

User avatar
Yeager
KVRian
1111 posts since 28 Jun, 2005

Re: Spline EQ - how to create a steep HPF?

Post Thu Aug 28, 2014 9:05 am

Novalis wrote:Ok, and then?
Then it looks like this :

Image

Simon Morrison
KVRist
104 posts since 22 Dec, 2010 from California

Re: Spline EQ - how to create a steep HPF?

Post Thu Aug 28, 2014 6:23 pm

Try the following settings (adjust frequency to taste):
SplineEQ HPF.jpg
You do not have the required permissions to view the files attached to this post.
Simon Morrison • Audio Architect • Mastering Engineer • Music Technologist
[ www.MorrisonStudios.com ]

User avatar
valerian_777
Banned
1182 posts since 24 Jun, 2014 from Giza Plateau

Re: Spline EQ - how to create a steep HPF?

Post Thu Aug 28, 2014 7:57 pm

Novalis wrote:I'm experimenting with Spline EQ, and I have to say, I've never heard an EQ that transparent so far.
Novalis wrote:I use the free version.
Since you was so excited i assumed that you bought it for the little price it's offered.
║▌║█║▌│║▌║▌█

User avatar
Novalis
KVRist
328 posts since 18 Sep, 2013

Re: Spline EQ - how to create a steep HPF?

Post Sun Aug 31, 2014 4:00 pm

@ Yeager

Ah cool, thanks.
Did not think of setting both bands to the same frequency.
This results in a very steep filter indeed.

Could this cause a lot of pre-ringing?

@ Simon

Thank you as well, but that's not very steep.

A_SN
KVRian
966 posts since 6 May, 2008 from Poland

Re: Spline EQ - how to create a steep HPF?

Post Mon Sep 01, 2014 12:17 am

Is that steep enough?

Image

I assume you want to cut the infrasounds out of your mix, then Yeager does it right. Just keep your dots close together like Yeager did and turn up the resolution.

As for the pre-ringing it depends. Generally the answer would be yes, but actually that's only if you cut in the thick of a sound. For instance, if you cut in the middle of the spectrum of a sound, then yes, it's going to ring. But if you cut in a silent part of the spectrum then not really, mostly if you cut out infrasounds or ultrasounds, since your ear would filter out any ringing if there was any.

Think of it like clipping a sound in the time domain (this is the equivalent of what happens in the frequency domain). If you clip a sound in the middle of let's say a note, you're going to hear a sharp click. And the longer the fade-out the less clicky it's going to be. But if you clip in the middle of a silence then you're not going to hear any click at all. Same thing here but in the frequency domain, it's not an analogy, a click is a straight vertical line in the time-frequency plane, ringing is a straight horizontal line, so a click in one domain is a ring in the other if you will.

And if you do have ringing but it's outside your hearing range (probably 30 Hz - 16 kHz) then it's as if you had a click in a sound before you were there to hear the sound, so yeah, your ear would filter that out by not hearing it.
Simon Morrison wrote:Try the following settings (adjust frequency to taste):
Wow okay, this thread just made me realise I should perhaps make a video explaining how to make curves. Never thought I'd have to, I just assumed it would be pretty obvious. Never thought anyone would look for a simple high pass filter preset either....

Now I understand why you'd want to do it like this, because usually in most EQs you'd do a whole filter with just one control point and choosing a filter type. But here it's different, you make the curves yourself, and you wouldn't use slope for that, you would use 2 points for a LPF or HPF, at least 3 points for a notch filter and usually 4 for a bandpass/bandstop. I guess I should make a video explaining that.
Developer of Photosounder (a spectral editor/synth), SplineEQ and Spiral

User avatar
Novalis
KVRist
328 posts since 18 Sep, 2013

Re: Spline EQ - how to create a steep HPF?

Post Thu Sep 04, 2014 2:11 pm

Thank you very much!

Yes, a video would be very helpful indeed, and much appreciated.
I think most people who are used to conventional EQs (which is pretty much all there is, right?) struggle a bit with Spline EQ.

Actually the most important information is, that you have to use more than one point!
Now that I know and understand this, Spline EQ begins to make much more sense.

A_SN
KVRian
966 posts since 6 May, 2008 from Poland

Re: Spline EQ - how to create a steep HPF?

Post Wed Nov 05, 2014 4:44 am

Novalis wrote:Thank you very much!

Yes, a video would be very helpful indeed, and much appreciated.
I think most people who are used to conventional EQs (which is pretty much all there is, right?) struggle a bit with Spline EQ.

Actually the most important information is, that you have to use more than one point!
Now that I know and understand this, Spline EQ begins to make much more sense.
I'm writing the script for the video, I've done the part that details how curves work, can you tell me if I missed anything that would need being covered?

"The first thing you need to know about SplineEQ is that it uses splines, and because of that it works quite differently from other EQs. Traditionally EQs use bands of different types that work independently from each other. In SplineEQ the entire equalisation curve goes through those yellow control points. That means that in order to create any type of filter you need at least two control points.

To create a low shelf filter just have two control points, the leftmost one below the other. The position of those two points determines all the characteristics of the filter. A low pass filter is the same except with the lowest point brought all the way down to minus infinity. And high shelf and high pass filters are made the same way by having the lowest control point to the right.

You can make a peak or notch filter by having two control points at about the same base gain level, then create a third point in between those two points. You can make a band pass or band stop filter by combining a low and high pass filter. Note how so far we haven't touched the slopes parameters, which is unnecessary in order to make basic filters.

You can also make curves that couldn't be created using those basic filter types in a traditional EQ like this one, or you can adjust the shape of a curve segment very precisely by adding an extra control point. Here's an example, we have a high shelf filter, but I don't want the transition between the two points to look so symmetrical. I can just add a point in between the two, adjust the slope parameter to give the curve the angle I want when it goes through that new control point, and place it where I want to get the desired asymmetry."

Yeah I write the whole thing before recording, that's how you avoid spending the first 3 minutes not saying or showing anything interesting like so many tutorial videos do lol. I'm being seriously slow at writing this btw, dunno why, I hate it.

Btw I want to end the video with an explanation of why more resolution doesn't mean a better sound and can even mean a worse sound, and show the effects of ringing and how they compare to clicks when clipping a sound, but it might take several minutes and it might be kinda heavy, should I do it anyway?
Developer of Photosounder (a spectral editor/synth), SplineEQ and Spiral

Return to “Photosounder”