# Using Convolution reverb for Horror Effect



## composerguy78 (Jan 2, 2017)

I am scoring a horror movie and I'm looking to create some scary sound patches. 
I just opened up the NI instrument The Giant and came across the Cinematic setting. It basically uses a convolution reverb to process the sound source. I'm guessing this technique is well known? It works really well, it's basically using a convolution recording of a percussion scrape - in this case a gong, cymbal etc. to process the piano sounds set at 100% wet and it sounds like a more playable gong/cymbal scrape. or a cross between the two. 

I'd like to use this method further to create some more instruments (not just limit myself to NI's The Giant). 

Could anyone recommend any other samplers which do this? or perhaps there are blog posts out there on how to do this? I was thinking I could load up a space designer patch with some sounds and put anything through it and see sounds scary? Any suggestions gratefully received!

Thx

Felix


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## rJames (Jan 2, 2017)

Yes you can use space designer. Make it 100% wet. 
The longer the sample that is your convolution sample, the longer your result. I.e. Put a 2 sec white noise as convolution with a spicatto note and the result is a 2 sec stretch of your spicatto note. White noise is full spectrum. Shorter convolution samples stay closer to your original sound with a new tonal color. This is the way to think about it.
A scrape noise as convolution will reveal your entire input sound multiplied thru the color of the scrape over time. And it will move in stereo with whatever your convolution sample does in stereo over time. 
Better for strange ambiences than for sharp scary sounds although super short convolution samples can alter sounds and remain somewhat sharp. There are a lot of strange samples that come with sound designer. 
Ron


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## composerguy78 (Jan 3, 2017)

Thank you so much Ron. I really appreciate that. Great explanation too. I will give this some experimentation.

Best

Felix


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## Krakatau (Jan 3, 2017)

If you allow me...

...i experienced to create IRs from scratch designed to match a chosen scale or another.

For odd, marred horror ambiances it gave convincing results when the scale in where you're playing was in complete contradiction with the one chosen as IR (for instance C# pentatonic while playing C Major) 

In fact, the technique is way more effective when both performance and IR matches the same scale and therefore the use in so to say "counterhamony" requires different types of adjustments

If you're curious to give this a try, here some of them (that where primarily part of my contribution the kvraudio developer challenge of 2012)

https://www.dropbox.com/s/eorkjn5qer0cwv0/Counterharmonic IRs.zip?dl=0

Load them into space designer and search for the relevant dry/wet equilibration 

bear in mind though : you're performance should strictly match the chosen scale

in summary : 

12 chromatic transpositions (from A to G#) 

8 different length from "a" (about 12 seconds) to "h" (about 93.75 milliseconds...their length being each time 
divided by two)

11 process chains (inducing of course, different sonic textures)

Notice though, you can perfectly use them as harmony enhancements (musically talking, nothing to do with the sound engineering paradigm !) by matching the Pentatonic scales their corresponding to, (as the example underlined above : their all supposed to be in counterharmonies with MAJOR scales only !) ...but in the cas you'll urgently need a different dry/wet equilibration because the IRs might be way more responsive in the case !

My two cents, hope you'll like it

P.S. perhaps it would be more effective to copy/paste the link of my dropbox rather than clicking the link..?


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## composerguy78 (Jan 4, 2017)

Hey there,
This is so kind of you to offer up this technique! I am downloading those files from your dropbox and I will let you know how I get on. 
much appreciated!
Felix


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## desert (Jan 6, 2017)

Krakatau said:


> If you allow me...
> 
> ...i experienced to create IRs from scratch designed to match a chosen scale or another.
> 
> ...


Do you mind if I download this, as well? I'm curious on how this works. (Your dropbox link doesn't work)


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## Chandler (Jan 6, 2017)

It should work with any IR loader. Try making some IRs yourself by hitting various things. You can also try manipulating white noise to make an IR.

Something else that might work is MMorph. Listen to the last sound sample on the page called Tagirijus - MMorph demo. 
It has some crazy monster sounds made by mixing a human voice with stone, water, fire and animal sounds. It might or might not be easier to work with than IRs.


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## Krakatau (Jan 7, 2017)

Chandler said:


> It should work with any IR loader. Try making some IRs yourself by hitting various things. You can also try manipulating white noise to make an IR.
> 
> Something else that might work is MMorph. Listen to the last sound sample on the page called Tagirijus - MMorph demo.
> It has some crazy monster sounds made by mixing a human voice with stone, water, fire and animal sounds. It might or might not be easier to work with than IRs.



seems like a relevant advice for horror movie especially considering a related content into the scenario (fire, scary animals, etc...) as far as i can judge...

On a more closer composing aspect i can suggest the discussion, down on this page on the metasynth's forum :

http://metasynth.com/wikifarm/metas...ideo#comment_8ab25f895a643390729442f10ed9a452

...in where i explained the basic in creating scale-related impulse responses (under my real name) using the image synth room within Metasynth

Some point to underline that aren't mentioned in the related post, though :

*1) - *in our case you'll need to create IRs than shall enhance the note that AREN'T included in the scale in use (this assuming there would be no scale transitions in your composition)

*2) -* you better avoid using sine waves as sound sources because their resulting IR will be highly unresponsive to notes that aren't included in it scale, better user other waveform with a minimum of harmonic content

*3) -* If you don't own Metasynth, it is always possible (but more complicated) to do the trick within a more conventional DAW at the moment you can load a synth that can decently play the appropriate number of voices simultaneously, you might even consider the tessiture of the instruments (or instrument's section) that is on focus and then bound the number of simultaneous voices consequently,...at least it make sense looking for an harmony enhancement, perhaps not much in our case

notice that the focus, as far as i understand music theory, might be atonal but not so to say achromatic, i assume a thin and skilled ear might find some room to exploit this ambiguous mood for harmony transition, for instance

BTW to give a example at my level of sensitivity of what i might compare as similar odd, dissonating ambiance into published production/composition ta here a specific passage from the Band Van Der Graaf Generator (Interference Pattern/ Trisector) appearing twice* (from 1’42’’ to 1’54’’ and 3’25’’ to 3’37’’)* that might be very talking on that purpose IMHO :



the melodic line of Hammill's voice being here deliberately out of scale, i can't define exactly if this passage is ruled by a same counter-harmonic contradiction but it's very similar in mood

As far as i can imagine a related horror soundtrack , it reminds me of either the laughing of a macabre situation (as an exulting maniac), the careless though of someone unaware of a deadly danger around him, or someone singing ,trying to give himself courage face to an horrifying situation while turning insane by terror

I even say it might helps not being English based because i'm not aware of the lyrics immediately...but this might likely even increase this horrendous feeling, knowing the lyrical intelligence of Peter Hammill as author !

I think the main interest this way to create and use IRs is more relevant harmonically and you will likely avoid at a certain degree a long trial and error process

Alexandre Borcic


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