Impulse Responses without the Impuse

Tutorial | Oct 30, 2024

In this video, I discovered that the Unfilter plugin, which I initially used primarily for removing resonances, has a fascinating feature that allows you to export transfer curves as impulse responses. This capability enables you to mimic the resonances and filter characteristics of one sound on another, creating a more cohesive and authentic sound environment for your audio projects. If you own Unfilter, give this feature a try; if not, consider adding it to your wishlist for future purchases.

You can watch the Video on Youtube

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• Unfilter by Zynaptiq

Summary #

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

In this video, I explore a plugin called Unfilter, which I've had for a while but never fully utilized until recently. This plugin is quite expensive, typically priced around $300, but I managed to purchase it during a sale for half the price. If you're considering getting it, maybe add it to your wishlist, as it offers some intriguing features.

Unfilter works by analyzing what filtering has been applied to a signal, then attempts to reverse that filtering to restore the original sound. For instance, if you play a guitar through an amp or an amp simulation, Unfilter analyzes the impact of the amp on the signal and applies an inverse filter to counteract those effects. This can be handy if you want to remove unwanted coloration from recordings.

In my demonstration, I use a piano recording sourced from YouTube, captured in a room with a smartphone, which introduced various resonances and filter effects. By enabling the learn feature in Unfilter, the plugin identifies the transfer curve—or the filter applied to the piano sound—and attempts to neutralize it, effectively linearizing the sound. Typically, I use Unfilter to remove resonances from different tracks or instruments by adjusting the process knob, which inverts the identified filter curve to clean up the sound.

What's fascinating is the ability to export the identified transfer curve as an impulse response. This discovery was a major revelation for me, as it opens up creative possibilities. For example, I can take the impulse response derived from the old piano recording and apply it to a clean piano sound to mimic the original recording's acoustics, effectively making the clean piano sound as though it was recorded in the same room.

This technique isn't limited to pianos; it's applicable to various instruments and samples. If you have disparate sounds and want them to blend more seamlessly, you can use impulse responses to impart the same acoustic characteristics. Unfilter's ability to learn and export these characteristics allows you to create a cohesive sound by matching the acoustic properties of different recordings.

Overall, Unfilter is not just a tool for removing resonances or refining audio; it's a versatile asset for sound design and production. By exploring its full potential, I've found new ways to experiment and create more cohesive mixes. If you already have Unfilter, I encourage you to try out this impulse response feature. For those who don't own it yet, consider keeping an eye out for sales. Thank you for watching, and remember to like and subscribe if you enjoyed the content. See you in the next video!

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] Hey folks welcome back to another video. Sometimes you have plugins installed for years. They lay
[00:00:06] around you never use them that much or maybe you use them only for one feature and at some point
[00:00:14] you find out they have actually more features and these features are kind of helpful or interesting
[00:00:19] and yeah this happened to me today here with this plugin called Unfilter and Unfilter is very
[00:00:25] expensive. I got this on a sale for half the price but at the moment I think it's around
[00:00:29] 300 bucks so it's very expensive. I know that right it's not like you have to buy it right now
[00:00:35] so maybe put it on a list if you want to have it but Unfilter maybe you already have it. I don't know
[00:00:41] so Unfilter here is a plugin that tries to find out what was done to a signal right in terms of filtering
[00:00:51] and then it tries to apply the inverted filter to your signal to actually remove it. So let's say
[00:00:59] you play some kind of guitar through a amp simulation or maybe through a real amp right and then you put
[00:01:07] this on and then this plugin tries to find out what the amp does to the signal and then it tries to
[00:01:13] apply the inverted transfer curve to the signal to remove everything that the amplifier does to your
[00:01:19] signal. I hope you know what I mean okay so here I have a piano recorded from YouTube sounds like this
[00:01:29] maybe put this here on bypass for a moment
[00:01:35] and you can hear it's recorded in some kind of room. I have here also the video
[00:01:46] from cancel or chance. Yeah it was recorded here through a phone inside of a room old piano not the
[00:01:58] best quality so a lot of things are happening in the process right from the piano going through this body
[00:02:04] giving all the resonances from the room going through a microphone inside of a smartphone so there's a lot of
[00:02:11] filtering happening right so you can take then this plug in here and put it on and when you hit play
[00:02:20] let's uh remove bypass here and enable learn
[00:02:25] you can see here the signal and it tries to find out you can see this here with the red line
[00:02:33] it tries to find out the transfer curve so this is the filter
[00:02:37] um that was applied to the piano or to the sound of the piano or at least that what the plug-in
[00:02:46] think it does it was applied
[00:02:48] and it tries really to learn here what's happening
[00:02:52] and this is not the match eq it doesn't take the full spectrum here right and then it tries to find
[00:02:58] out this curve and then it applies a different curve to this it's not the match eq it really
[00:03:03] tries to learn only what's happening with the signal here and where are the resonances and what
[00:03:10] kind of resonances are added to the signal and usually i use this plug in here for um
[00:03:16] removing these resonances right i put this on the master on my tracks or maybe on an instrument
[00:03:23] and then i have this transfer curve here and then i turn up here this process knob and this process knob here
[00:03:32] eqs this out or it tries to apply the inverted filter curve to my signal to remove
[00:03:40] actually all this crap and it tries to make the sound linear right so this is the idea behind it
[00:03:50] if i put this here to zero nothing happens so this is the original signal
[00:04:02] and then you have here this knob the waiting and the more you turn this up the more it uses the fletcher
[00:04:11] munson curve um for eq-ing you can see a set frequency waiting higher values progress progressively
[00:04:19] apply a fletcher munson curve to the final output so here you can also play around so i use this plugin
[00:04:26] more or less all the time for filtering out resonances and it works really great for that
[00:04:32] on all kinds of um sounds and tracks and masses and so on
[00:04:37] but what i find out is that you can actually take this curve here and export it as an impulse response
[00:04:47] so this is the main takeaway from this video so you can hit save here and just save it as an impulse response
[00:04:54] so we can say here old piano you have some options here for minimum phase and zero phase ordering and
[00:05:01] everything does something different here the signal point you can just leave this disabled just call it
[00:05:07] old piano right need save so now what we can do with this impulse response is that we can use let's say a clean piano sound
[00:05:19] piano take eight here for instance um and then let's see how this sounds
[00:05:25] so it's it sounds very clean right when you want to play with this piano to this piano it yeah it doesn't
[00:05:42] fit it it's not gluing together everyone talks about gluing on the internet right and when they say
[00:05:48] gluing that usually just mean um put a compressor a glue compressor on a on a drum bus but that's
[00:05:56] not what gluing means in my opinion gluing is also that you have the same frequencies
[00:06:00] that you play the same melody or in the same frequency ranges and so on it's not only that the dynamics
[00:06:07] behave in the same way so gluing can mean a lot of things in my opinion so here these two sounds sound
[00:06:14] you know not similar
[00:06:18] right it's a completely different sound they don't match so now we can take here the convolution reverb
[00:06:28] and can just put in this type of wave file we exported um i have to just search it here old piano there is
[00:06:37] it just drag it in so this is the wave file here we just exported from the Unfilter here and then we can
[00:06:44] just take or apply the same resonances that was applied to the old piano to this piano
[00:06:51] so you can fake this piano to sound like it was recorded in this room
[00:07:03] so you can fake this piano to sound like it was recorded in this room and this is not only interesting for
[00:07:20] uh piano sounds or for guitar sounds if you record something somewhere else right and there's a lot
[00:07:26] of filtering happening you can apply the same filters to your internal sounds and then they don't sound
[00:07:31] that clean anymore or they sound they were they were recorded in the same room but you can also imagine
[00:07:36] this is pretty handy for let's say you download some samples from the night some snare sounds right
[00:07:43] and then the snare sound in a different way in a certain way and then you have a clean click kick drum
[00:07:49] and then you can use this impulse response and make the kick drum sound like it was recorded in the same
[00:07:56] room than the snare sound something like this right where you want to apply the same filtering to a sound
[00:08:03] so first you need Unfilter to actually learn what was done to the signal in terms of filtering then you
[00:08:11] export this here as an impulse response and then you can can apply the same process to a different sound
[00:08:17] to glue them together in a certain way so this is very interesting for me also here um let's say if
[00:08:25] you want to make um piano simulations right it's all about these harmonics it's all about these uh formats
[00:08:33] that um or static frequencies that are applied when you record a piano to make a piano sound realistic
[00:08:41] um so this is very handy and sometimes interesting so this Unfilter plug-in is not only interesting to
[00:08:48] remove resonances or to finalize mixes or to straighten out frequency responses of masters or mixes you can
[00:08:58] also just learn what's happening inside of a signal in terms of resonances or filtering and then use that
[00:09:06] and export it as an impulse response and apply to a different signal so it's very cool and i have to
[00:09:12] experiment with that in the future of course but i just found this out and i want to make a video on it
[00:09:18] so if you own Unfilter try this out very handy if you don't own Unfilter then maybe put it on your um
[00:09:26] i have to buy this in the future list or whatever and then get it in a sale but i think it's very handy
[00:09:34] sometimes to use this right so that's it for this video thanks for watching leave a like if you like
[00:09:39] the video if you don't like the video then don't leave a like um do whatever or just block me i don't
[00:09:45] know whatever subscribe to this channel see you in the next video bye
[00:09:49] Thank you.