KVR Audio

androidlove · Post by **androidlove** » Sun Feb 19, 2006 11:35 pm

i've been happy with the buzzroom verb, so i haven't even exlpored ir's for reverb. i just figured they were fer foley work

anyway, i get the feeling ir's do a lot. could ya tell me what those things are?

arke · Post by **arke** » Sun Feb 19, 2006 11:39 pm

basically, an impulse is an infinetely short "pop" which is recorded with a good amount of tail time. The changes in characteristics can then be applied to any other sound through some clever filtering using a recording of that "impulse response". Basically, you can use it for reverbs but also for filters or pretty much just to make something sound like it is in a certain room (theres freely available IRs for things like buckets, woods, small rooms, toilets, under a bench, in a park, in a car, whatever).

androidlove · Post by **androidlove** » Sun Feb 19, 2006 11:42 pm

arke wrote:basically, an impulse is an infinetely short "pop" which is recorded with a good amount of tail time. The changes in characteristics can then be applied to any other sound through some clever filtering using a recording of that "impulse response". Basically, you can use it for reverbs but also for filters or pretty much just to make something sound like it is in a certain room (theres freely available IRs for things like buckets, woods, small rooms, toilets, under a bench, in a park, in a car, whatever).

yea, foley work. but it seems i've read they can do other jobs

jplanet · Post by **jplanet** » Sun Feb 19, 2006 11:49 pm

Also good for amplifier cabinet emulations, like those in Guitar Rig...

Music Engineer · Post by **Music Engineer** » Mon Feb 20, 2006 12:22 am

in terms of signal processing, convolution can be used to exactly simulate any linear time invariant (LTI) system. linear means, that a weighted sum of different input signals passed through the system results in the same output-signal as if the system was applied to the individual input signals and the outputs were mixed afterwards, that is (in pseudocode):

Code: Select all

systemOut(weight1*signal1) + systemOut(weight2*signal2) = systemOut(weight1*signal1 + weight2*signal2)

also, if the input to a linear system is sine, the output is also a sine with the same frequency but possibly different amplitude and phase. time invariance on the other hand means, that the system characteristics do not change over time

examples for LTI-systems are: rooms (real or artificial), filters/equalizers, microphones, loudspeakers, ...

examples for nonlinear systems: distortion, exiters, pitch-shifters, subharmonic-generators, ...

examples for time-variant systems: dynamics, time-varying filters, modulation-effects, ...

scamme · Post by **scamme** » Mon Feb 20, 2006 12:30 am

As far as i know Voxengo's Boogex uses IR's for cabinets too.

androidlove · Post by **androidlove** » Mon Feb 20, 2006 2:24 am

thanx braindoc

vurt · Post by **vurt** » Mon Feb 20, 2006 2:27 am

i use em as samples in drum samplers, or in anysampler, use em as waveforms in synths that can import waveforms.
pretty much use em for most things.

androidlove · Post by **androidlove** » Mon Feb 20, 2006 2:47 am

ha ha, didn't think of that. i'm checkin out some pops right now

shamann · Post by **shamann** » Mon Feb 20, 2006 2:48 am

You can do all sorts of cool stuff with convolution. Just take any sample and convolve it with any other sample and see what you get.

I just convolved an 88hz sine wave with 58hz sine wave, got pretty good waveform in the end.

You can also get pretty good special effect reverbs that might be harder to come by with a regular reverb. Try creating one second of white noise in an audio editor, start filtering or applying effects to it. Cut it up, reverse it, whatever.

When you are done, select the whole thing and apply a fade out envelope (preferably something like a -20dB exponential fade, so you get a good tail). Now take that sample and use it as an IR.

androidlove · Post by **androidlove** » Mon Feb 20, 2006 2:52 am

will do

Barbed Wire Kiss · Post by **Barbed Wire Kiss** » Mon Feb 20, 2006 10:22 am

shamann wrote:You can do all sorts of cool stuff with convolution. Just take any sample and convolve it with any other sample and see what you get.

I just convolved an 88hz sine wave with 58hz sine wave, got pretty good waveform in the end.

You can also get pretty good special effect reverbs that might be harder to come by with a regular reverb. Try creating one second of white noise in an audio editor, start filtering or applying effects to it. Cut it up, reverse it, whatever.

When you are done, select the whole thing and apply a fade out envelope (preferably something like a -20dB exponential fade, so you get a good tail). Now take that sample and use it as an IR.

What effects work well on an IR, for example, would a non-linear effect really have any worthwhile effect?

cron · Post by **cron** » Mon Feb 20, 2006 10:29 am

My last track used non-reverb convolution tricks quite a bit. I used a sound which I got by recording myself drumming on the bridge as fast as possible with my fingers, then convolving it using a plucked harmonic as the IR. Ended up with a lovely staccato chiming.

Most simple sounds with a sharp attack and a 'natural' sounding decay work great in place of IRs for special effects.

Rangtangtang · Post by **Rangtangtang** » Mon Feb 20, 2006 10:36 am

I convolved one of my tracks whith the DR WHO synth sweep intro.

I wanted to get that DR WHO sound.

lowercase · Post by **lowercase** » Mon Feb 20, 2006 10:45 am

Spirit Canyon Audio!

what can ir's be used for besides reverb?