Re: seamless loops & windows tools (ambiloop vs Mobius)

[Giorgio Robino <giorgio.robino@gmail.com>]

a) about loop track saving / reuse:

Thanks Jeff for your very accurate and clear explanation!

Possibly I was not too clear in my explanation; In facts my process was this one:

1) I perform an overdubbed "perfect" loop (using ambiloop)


2) I save this track as the file loop.wav
3) I run an audio editor (using audition) and I INSERT JUXTAPOSING many instances (COPIES) of this loop.wav chunk: my aim now is to play for example 10 contingous clicles of loop.wav .. 


HERE I realize clicks... ( ! ) mmhh....now come in my mind the possible problem: phearps is the audio editor that do not perfectly juxtapose contigous audio chunks .. ?! .... (I used here a functionality called "multiply" that I believed was working doing perfect jusxatposition (at "sample level")  but pheraps this was not true: I have to re-test...

Anyway thanks again for your clear analysis, that is helping in understand the point!


b) about seamless loop editing:
Thanks Rick, yes I'm aware of the little fade-in - fade-out method to avoid clicks.
sorry, again I was not too clear in my inbitial post: I refer to an editor helping in realization of "perfect loops"

I mean something like the old beautiful "infinity" on Mac ...

Au revoir
giorgio

2011/3/2 Jeff Larson <jeff.larson@sailpoint.com>

> Indeed, does the alternative sw Mobius ( http://www.circularlabs.com ) 

> save .wav without start-end clicks / artifacts ? 

I think I know what your problem is.  It isn't really an "artifact",

the loop is being saved exactly the way it was recorded.  The problem

is that in a looper, loops normally play from beginning to end and

then repeat.  If you overdub and you let the overdub carry over the

loop boundary, then the audio will not be faded to zero at the

begininning and end of the loop.  When the looper plays this audio

continuously, you don't notice this, it sounds like seamless audio

without clicks.  But if you save this loop to a file and play the loop

in an application that is not a looper, there will be a click at the

beginning and end of the audio.

This is difficult to talk about without pictures.

Layer 1: rrrrrrrr

Layer 2: ----oooo

Layer 3: oo------

The letter 'r' means the loop was being recorded for the first time,

'-' means the loop was playing, and 'o' means overdubing.

The result will look like this:

    oo--oooo

In order for the overdub to sound seamless it is important that the

looper *not* fade the starting and ending edges of this loop to zero.

When the loop is allowed to play forever, you want it to sound like

this:

    oo--oooooo--oooooo--oooo

If you fade the edges of the loop to zero...

    _o--ooo_

Here '_' means silence.  The faded loop will sound like this when it

plays:

    _o--ooo__o--ooo__o--ooo_

You normally do not want this in a looper, the faded edges will be

audible as a "fade bump" that you will hear every time the loop

repeats.

If you save an unfaded loop to a file then bring it into an audio

application that is not a looper, the start and end of the wave form

will have sharp edges that will sound like clicks if you play the wave

form without looping it.  If you need to do this then you need to edit

the wave file and fade the edges, this is sometimes called "top and

tail" fading.

So to answer your question, Mobius will save loops WITHOUT

top and tail fading so that you can load them back into Mobius

and have them play seamlessly.  If you want to save Mobius loops

and use them in a different audio application, you will need

to edit them and fade the edges.  Most pro audio editors

provided an easy way to do this.

Jeff

-- 
"Siamo polvere di stelle, siamo oro, e dobbiamo far ritorno al giardino" (Joni Mitchell)
Giorgio Robino http://solyaris.altervista.org