How does an 1024 IR become a 512 one?

[guitarnerdswe]

I'm just wondering about something. As far as I understand, you can look at an IR as an eq with ( for the high res mode in the Axe ) 1024 points of adjustments. How do you make an 512 point IR of an 1024 one? I mean, to you skip every other point of adjusment, or how do you do it? :?

 

[javajunkie]

I'm just wondering about something. As far as I understand, you can look at an IR as an eq with ( for the high res mode in the Axe ) 1024 points of adjustments. How do you make an 512 point IR of an 1024 one? I mean, to you skip every other point of adjusment, or how do you do it? :?

You remove part of the end. The 1024 and 512 are the number of samples used.

 

[guitarnerdswe]

I'm just wondering about something. As far as I understand, you can look at an IR as an eq with ( for the high res mode in the Axe ) 1024 points of adjustments. How do you make an 512 point IR of an 1024 one? I mean, to you skip every other point of adjusment, or how do you do it? :?

You remove part of the end. The 1024 and 512 are the number of samples used.

Okay. Seems like I'm missing something. Could you explain a bit more, of point me to some information?

 

[javajunkie]

http://en.wikipedia.org/wiki/Impulse_response

From what I understand it basically captures the frequency response and phase over a set amount of time (the time is dictated by the # of samples at the sampling rate)

http://en.wikipedia.org/wiki/Convolution_reverb

 

[AndrewSimon]

I'm just wondering about something. As far as I understand, you can look at an IR as an eq with ( for the high res mode in the Axe ) 1024 points of adjustments. How do you make an 512 point IR of an 1024 one? I mean, to you skip every other point of adjusment, or how do you do it? :?

You remove part of the end. The 1024 and 512 are the number of samples used.

Okay. Seems like I'm missing something. Could you explain a bit more, of point me to some information?

IR is like an EQ .... note "like" !

It's a very short wave file(22ms), so short that you can describe it in 1024 points (samples of 24bit).
The 512 point one is even shorter only 11ms.

So it's the same resolution (48KHz24bit) but half the lenght.
Because the most important data sits at the beginning of the IR you can
cut off the second half without loosing the "vital spirit" of the cab.

 

[AlbertA]

More wiki links :mrgreen:

http://en.wikipedia.org/wiki/Finite_impulse_response