What Are Impulse Files?

think of it as the imprint of an echo or the imprint of changes in a sound going through a piece of equipment.
A convolver takes your sound and applies the imprint.
An impulse of a concert hall takes your sound and mathematically changes it to make it sound like you're playing in the hall.

definition with pictures halfway down the page:
CKSDE- Download - Impulse Response Files
 
You're in a room or hall or arena. You set up a mic. You make some sort of impulsive sound, like a balloon popping, clap, gunshot etc. You record the resulting echoes and reverberation. You now have an impulse response.
 
I guess the more common place you see an impulse response (IR) used is with reverb.

In the case of reverb, an impulse response is (as already mentioned) a capture of the reverb response to an impulse sound in a particular space

So if you wanted to make it sound (somewhat) like a vocal was being performed in the Sydney Opera house, find an Impulse Response that was recorded in the opera house, load it into your convolution reverb plugin and use it as your reverb for the vocal, hey presto you have an approximation of how that vocal would sound if it had been performed in the Sydney Opera house (or at least in the exact spot the mic was placed to capture the impulse response)

Many convolution reverbs will also allow you to record your own impulse responses as well as offering a large selection of premade ones. So if you love how the reverb sounds in the stairwell at your office or in the shower for example, you can capture an IR and use it as a reverb in your mixes

The benefit of an Convolution Reverb using IRs is they often sound more natural (less metallic to my ears) than just a pure algorithm reverb. The downside is convolution reverbs can eat up a lot of CPU applying those IRs to the sounds

You could also use IRs to capture how a signal is affected by a particular piece of equipment, like a guitar cab or any of a million other things
 
Bristol Posse said:
I guess the more common place you see an impulse response (IR) used is with reverb.

In the case of reverb, an impulse response is (as already mentioned) a capture of the reverb response to an impulse sound in a particular space

So if you wanted to make it sound (somewhat) like a vocal was being performed in the Sydney Opera house, find an Impulse Response that was recorded in the opera house, load it into your convolution reverb plugin and use it as your reverb for the vocal, hey presto you have an approximation of how that vocal would sound if it had been performed in the Sydney Opera house (or at least in the exact spot the mic was placed to capture the impulse response)

Many convolution reverbs will also allow you to record your own impulse responses as well as offering a large selection of premade ones. So if you love how the reverb sounds in the stairwell at your office or in the shower for example, you can capture an IR and use it as a reverb in your mixes

The benefit of an Convolution Reverb using IRs is they often sound more natural (less metallic to my ears) than just a pure algorithm reverb. The downside is convolution reverbs can eat up a lot of CPU applying those IRs to the sounds

You could also use IRs to capture how a signal is affected by a particular piece of equipment, like a guitar cab or any of a million other things
Click to expand...

Thank you very much for the explanation. I sort of had an idea of what it was, but no idea how to go about using one. So now I just need to look for the thing highlighted in red up there and try it out.

Sounds like fun...and out of the hundreds of thousands of digital reverb choices I have, I don't love any of them.
 
chrisharris said:
Thank you very much for the explanation. I sort of had an idea of what it was, but no idea how to go about using one. So now I just need to look for the thing highlighted in red up there and try it out.

Sounds like fun...and out of the hundreds of thousands of digital reverb choices I have, I don't love any of them.
Click to expand...

You use Reaper?

Reaverb is the plug you want.
 
The interesting thing about convolution reverbs is that it is not just impulse files that you load into them. You can load in any WAV and use that to generate a 'reverb'. You can generate some freaky effects that way.
 
Greg_L said:
You use Reaper?

Reaverb is the plug you want.
Click to expand...

Ahh...ok, cool. Does it have impulses in there? I'm assuming you can download impulses from...places, right?

I'm getting lazier in my old age, but it's not that I'm too lazy to open Reaper and figure it out...I'm not near my DAW right now, so I can't.
 
gecko zzed said:
The interesting thing about convolution reverbs is that it is not just impulse files that you load into them. You can load in any WAV and use that to generate a 'reverb'. You can generate some freaky effects that way.
Click to expand...

I don't understand what you mean, but I'll try it.

So...I could totally isolate my vocal by singing with one of those mobile vocal booths, then I could create an impulse of my room, then mix that reverb back into the vocal. OR....I could just ditch the booth, lol.
 
chrisharris said:
I don't understand what you mean, but I'll try it.
Click to expand...

Conventional impulse files are available on the web. You can download them and load them into Reaverb (or SIR, or whatever convolution plugin you can find). But you can also load in a file of, say, a car driving down the road, or any other thing, and use that to get weird effects.


chrisharris said:
So...I could totally isolate my vocal by singing with one of those mobile vocal booths, then I could create an impulse of my room, then mix that reverb back into the vocal. OR....I could just ditch the booth, lol.
Click to expand...

If you isolate your singing and get a totally dry sound, you can then insert Reaverb, load an impulse file and generate a reverb that replicates the particular venue in which that impulse file was recorded. Or you can create an impulse of your room and mix that back in, as you say. Better still, ditch the booth and use the room!
 
moresound said:
First trying Poppa bears reverb Goldilocks said "this reverb is to Hot", then she tried the next one, Momma bears reverb and said "this reverb is to cold" then went to the baby bears reverb and said "this reverb is just right!"

:D:p:D
Click to expand...


PERFECT!!!!


Thanks, guys...this sounds interesting, and I'm looking forward to trying it out. I'm sure I could have googled this stuff, but I wouldn't have known about ReaVerb or that this technology is awesome.
 
chrisharris said:
Ahh...ok, cool. Does it have impulses in there? I'm assuming you can download impulses from...places, right?

I'm getting lazier in my old age, but it's not that I'm too lazy to open Reaper and figure it out...I'm not near my DAW right now, so I can't.
Click to expand...

You have to go get some impulse files. They're everywhere on the net and most are free. Open Reaverb, and in the little dialog box you tell it where to find your reverb files and choose which reverb file you want.

I've got some good ones if you want them.
 
This is a screenshot of a wavform of an impulse file, it's boring to listen to one:
Screenshot2011-05-14at83226PM.png


You need this type of plugin (convolution reverb) to load the above file into to hear how it sounds:

Screenshot2011-05-14at83345PM.png

Screenshot2011-05-14at83418PM.png

Screenshot2011-05-14at83450PM.png
 
Impulse files are usually wav files in various bit and sample rates. There are some convolution plugins (such as SIR2) that use a proprietary file system for some of their impulses. SIR 2 will still load stereo and mono wav impulse files though.
 
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