EQ Cloning with Impulse Responses

Tutorial | Sep 30, 2024

In this video, I demonstrated how to clone EQ settings using impulse responses, showing the process with tools like an EQ curve analyzer, Ozone 8 EQ, and a convolution device. By recording the output of the Ozone 8 and using a test tone or Dirac signal, I showcased two methods to replicate the linear phase EQ setting. This technique is useful especially if you don't have a built-in linear phase EQ in your DAW like Bitwig.

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Summary #

Maybe you don't watch the video, here are some important takeaways:

In this video, I demonstrated how to clone or copy EQ settings using impulse responses, a technique that some people have been curious about. The process is quite straightforward, and I’ll walk you through it step by step.

I began by using an EQ curve analyzer, which isn't strictly necessary but helps explain how this technique works. First, I set it up as a generator and received it using an EQ curve analyzer as the receiver. In between, I used an Ozone 8 EQ to create a high-pass filter. I enabled the phase setting on the analyzer to see that in zero latency mode, it offsets the phase, which might not be desirable for some users who want a linear phase.

In Ozone 8 EQ, I switched to digital mode, which ensures the phase remains flat, though this introduces a latency of 64 milliseconds. I demonstrated adding a 30 Hz low cut with a steep filter setting of 48 dB per octave, showing the EQ curve analyzer that the phase remains unchanged.

To sample this EQ setting, I used the EQ curve analyzer to change the impulse sample’s loudness to 0 dB instead of the default -12 dB, ensuring the signal is normalized. After passing the signal through the Ozone 8 EQ, I intercepted it with a rolling sampler. The output was sampled, and I zoomed in to capture the specific portion of the signal.

Next, I showed creating another track, using the EQ curve analyzer as a generator once more. In between, I placed a convolution device set with a normal reverb and dragged in the captured signal. The signal exhibited a low cut at 30 Hz with a flat phase, effectively replicating the Ozone 8 EQ setting.

For those without an EQ curve analyzer or rolling sampler, I demoed an alternative using a test tone, specifically a Dirac signal, which is ideal for this purpose. I lowered the frequency to produce clicks and sampled a part of it, making sure to account for latency. I used this sample on the Ozone 8 EQ set to digital mode, this time cutting at 120 Hz for variety. After bouncing the output, I applied it to a convolution reverb, highlighting that the length of the signal matters to avoid excessive latency. Adjusting and re-bouncing until achieving the right length ensures minimal latency while replicating the EQ setting.

In summary, whether using an EQ curve analyzer and rolling sampler or a test tone, the process involves sending a normalized impulse signal through the EQ, capturing the output, and applying it with a convolution reverb to mimic the original EQ settings. This method effectively copies the EQ settings straightforwardly, especially faster with the right tools. If there are any questions or clarifications needed, feel free to ask in the comments. Thanks for watching, and don't forget to leave a thumbs up and subscribe!

Transcription #

This is what im talking about in this video. The text is transcribed by AI, so it might not be perfect. If you find any mistakes, please let me know.
You can also click on the timestamps to jump to the right part of the video, which should be helpful.

[00:00:00] So two weeks ago I showed you that I cloned or copied some EQ settings with impulse responses
[00:00:06] and some people wanted to know how this works.
[00:00:09] It's actually not very complicated.
[00:00:11] I show you this here in this video.
[00:00:14] First we use here an EQ curve analyzer.
[00:00:18] It's actually not needed, but it's cool to explain how this works.
[00:00:23] So let's set this here as a generator.
[00:00:27] We have here a generator and an EQ curve analyzer here as a receiver.
[00:00:31] And in between we use now here an ozone 8EQ.
[00:00:38] And we want to use here in high pass, right?
[00:00:43] So let's open up here the analyzer and we also enable here the face setting.
[00:00:52] So now you can see this is in zero latency mode, which means we have zero latency.
[00:00:59] What the tradeoff is that we change the face.
[00:01:01] As you can see here, we slowly offset the face.
[00:01:06] And some people don't want that.
[00:01:08] They want to have a linear face.
[00:01:10] And we can do this with this EQ here.
[00:01:12] And there's no linear face EQ in Bitwig.
[00:01:15] That's the reason why you want to sample this probably.
[00:01:19] So here there's a linear face mode, which is called digital.
[00:01:24] We switch it here to digital.
[00:01:27] And you can see now here the face is completely flat.
[00:01:31] So nothing changes.
[00:01:33] But the tradeoff is that we have now a latency here of 64 milliseconds because of that.
[00:01:41] And let's say you want to have some kind of low cut at 30 Hertz.
[00:01:49] Usually want to cut at 30 Hertz some at some point to get rid of some rumble.
[00:01:54] It's not like that you need it on every track, right?
[00:01:58] But sometimes you need a nice low cut at some point.
[00:02:03] And here you can do this or you can resample this with impulse response.
[00:02:06] So let's here also make the filter a bit steeper, 48 dB per octave, I think it is, or 48
[00:02:13] pull.
[00:02:14] No, I think it's 48 dB per octave.
[00:02:18] So now we have here a nice 30 Hertz low cut.
[00:02:21] So you can see here in no face change.
[00:02:25] So how can we sample this now?
[00:02:27] So the easiest way is without using Bitwig only things, we can just utilize here the
[00:02:34] EQ curve analyzer, right?
[00:02:36] And we can go to the first instance and change the impulse response or impulse sample loudness
[00:02:42] here to 0 dB instead of minus 12.
[00:02:46] So now it's normalized.
[00:02:48] So the sample that goes into the EQ is exactly 0 dB.
[00:02:53] You can see this also here on the view meters and also in here.
[00:02:59] And then it goes out of the EQ here at the end.
[00:03:03] And we can just intercept the signal with the rolling sampler.
[00:03:08] That's how I do it most of the times because it's just so easy and straightforward.
[00:03:13] You can see here we sampled this, the output.
[00:03:17] You can just highlight yourself and then zoom in with the scroll wheel or the mouse wheel.
[00:03:24] And all we need to do now is we create another track.
[00:03:31] And let's use the also EQ curve analyzer so you can see, set this generator.
[00:03:40] And in between now here we use a convolution device.
[00:03:46] And here's just a normal reverb in there all the way up, all the way up.
[00:03:52] And then we just take here one signal or one part and drag this in.
[00:03:59] You can see this is now 62 milliseconds long.
[00:04:02] It's exactly the, not exactly but kind of the same, roughly the same latency here.
[00:04:10] And the pre-ringing is needed in order that the low cut works perfectly.
[00:04:15] You can see here in the signal coming out of the convolution reverb we have a low cut.
[00:04:22] The face is completely flat.
[00:04:25] So now we copied basically this EQ setting here from the ozone aid to the convolution
[00:04:32] reverb with just recording the output of this ozone aid.
[00:04:41] It's actually very straightforward.
[00:04:44] So if you don't want to use the EQ curve analyzer or you don't own it, right?
[00:04:50] Or let's say you don't have the rolling sampler and you don't want to use the rolling sampler.
[00:04:56] You can do it in a different way.
[00:05:00] It involves or it uses the test tone.
[00:05:06] So the test tone here, you need to have the mix here at 100%.
[00:05:11] The test tone has here this direct or direct.
[00:05:14] I don't know how it's called in English in German.
[00:05:17] It's just the Dirac because that's the name of the scientist Dirac or mathematician.
[00:05:24] I don't know what he was.
[00:05:25] I think he was a mathematician.
[00:05:28] Then we pull this down to the lowest frequency here and then we get some clicks.
[00:05:34] Right?
[00:05:37] So we just sample here a part bounce, no dither, 32 bit post fader.
[00:05:45] And then we have in here.
[00:05:49] Let's zoom this in and see we have here a click in there, right?
[00:05:54] This signal.
[00:05:57] And what I do sometimes is I just let's say use your sampler.
[00:06:07] You maybe don't need to use the sampler.
[00:06:09] You can just play this one back here.
[00:06:13] Let's track this into the sampler here and zoom in.
[00:06:19] Actually, let's use the signal here.
[00:06:24] I think it's better.
[00:06:26] Just single this out.
[00:06:29] Something like this.
[00:06:35] You need to include your, by the way, the, what's the name?
[00:06:40] The latency.
[00:06:41] You need to include the latency here.
[00:06:43] So we don't need to, you don't want to go with the signal to the beginning, right?
[00:06:48] You want to have it here in the middle.
[00:06:52] So let's loop this.
[00:06:55] And this is the impulse.
[00:06:58] And on that we use the ozone aid again.
[00:07:07] And we do the same thing.
[00:07:12] Digital here.
[00:07:14] Let's go this time to one on 20 hertz just for the, for the example here.
[00:07:19] And all you need to do now is to bounce this.
[00:07:25] Post-radar 32 bits.
[00:07:28] Right.
[00:07:29] You can see here.
[00:07:31] We have an result.
[00:07:35] And then we use an EQ curve analyzer again.
[00:07:46] And here we use convolution again.
[00:07:50] And then we can use the sample here.
[00:07:52] Put it in there.
[00:07:55] Right.
[00:07:57] Looks something like this.
[00:08:01] That's not really sure.
[00:08:08] That's correct.
[00:08:11] So what you need to do now is to figure out the exact latency or the length.
[00:08:17] You can just delete this here and make this way shorter.
[00:08:23] Something like this.
[00:08:28] And then re-sample.
[00:08:36] So that's, that's more or less the hard part that you need to find the latency length here
[00:08:41] to correct one.
[00:08:46] Files to the stone bounds.
[00:08:53] This one is one on seven milliseconds long.
[00:08:56] It's still too long.
[00:08:58] I mean, it still works here as you can see, but we don't want to use too much latency.
[00:09:08] Can we see actually the length here in milliseconds?
[00:09:13] Probably not.
[00:09:14] Okay.
[00:09:15] Let's try this one.
[00:09:18] Bounce.
[00:09:21] Test tone four.
[00:09:25] That's much better.
[00:09:31] So we have some problems here, but it's not really important, I think.
[00:09:36] But you can see how this works.
[00:09:38] And when you figure it out here, the correct length, you can reuse it for different or
[00:09:44] other EQ settings and then just bounce it out.
[00:09:47] So all you need to do is to use a Dirac signal, impulse signal and send it through the EQ
[00:09:55] signal, then record it at the output.
[00:09:57] And yeah, if everything is zero dB or normalized, you can just put it into the convolution reverb
[00:10:04] here, put the wet gain up, put the mix all the way up and you can replicate the EQ setting.
[00:10:10] It's actually not very hard in my opinion.
[00:10:13] And if you own rolling sampler or the EQ curve analyzer, it's even faster sometimes.
[00:10:19] So I want to show you this, how this works in Bitwig.
[00:10:22] I hope it's clear.
[00:10:25] If you have questions, let me know in the comments down below.
[00:10:27] Leave a thumbs up in the subscription.
[00:10:30] Thanks for watching and bye.
[00:10:31] [ wind blowing ]