impulses

[blue]

ok, over the last while i have seen this word impulse used in relation to recording guitar on a computer.  please excuse my ignorance, but if you don't know you gotta ask?  what is an impulse?

[MDV]

Its a wav file thats applied to the input signal that simultes the effect of a speaker, cab, room, power section of an amp and so on and so forth that makes a dry DI from a preamp sound more like a real amp driving a speaker in a room.

They're loaded in your DAW as a VST or effect and applied to a track the same way as you would a DAW effect or an amp sim to a dry signal.

Tis good stuff, pretty usefull.

[tomjackson]

Never heard of them but found this:-

An impulse response (IR) of a cabinet is a data representation of the transfer function of the cabinet. It is obtained by sending a very transient signal through the cabinet, mic'ing it with a measurement mic, and recording the change.

That "change file" or IR, is used by a plugin or software application called a "convolution engine", that takes that IR plot, and applies the encoded transfer function to whatever signal you're sending through the engine.

Sounds like an algorithm of a guitar cabinet response, I've heard this before but in relation to reverbs where you measure the response in your favorite hall/church/room and then it can be applied to what you put through it.

Certainly Tis good stuff....

[blue]

thanks guys, that's most illumiating.  these can be used in most DAW's then, can they? could be worth looking into.

[MDV]

They can be used in any DAW.

I got some off somewhere in Andy Sneaps forum. A search of ultimate metal or probably even google should bring them up. You need the (tiny) app to run them, and a bunch of actual impulse files. Its free and easy.

[gingataff]

They are mostly used to provide accurate sounding reverbs of real places, such as concert halls, churches, clubs, bathrooms etc. but you could send the signal through almost anything, analyse the change in the soundwave and use this information to modify any other sound source.
There are IRs of places, speaker cabs, mics, amps, outboard gear, ..the list is pretty long. You can even find impulses of line6 pod presets!
Of course you need software to use the IR and not all DAWs have them included, but there are some free ones like LA Convolver.

[JDC]

MDV which cab impulse do you use? I'm still using the engl 4x12 one in revalver, I've got a bogner uberkab one somewhere but I haven't got round to trying it yet

[Oli]

Using impulses for reverb i find works really well, and sounds great... but in my (admittedly fairly limited) experience with using poweramp and cab impulses with my preamp. It still just doesn't feel right!

[MDV]

MDV which cab impulse do you use? I'm still using the engl 4x12 one in revalver, I've got a bogner uberkab one somewhere but I haven't got round to trying it yet

No paticular one. I just experimented with them a bit. I dont even remember the name of the plugn I used :lol:  I'm on my laptop at the moment so I cant check.

[gwEm]

which is a good VST for applying the impulses? keFIR, Convolver, FreeVerb3?

[_tom_]

I heard keFIR is good, also Voxengo Booxex is free and meant to be quite good.

[exoslime]

I heard keFIR is good, also Voxengo Booxex is free and meant to be quite good.

i use that one too

[gwEm]

my marshall 20/20 has line out. if its not frequency compensated, it might be a good way for me to experiment. i sort of hope its not!