Changing tempo to a whole song

[unguitar]

Hi,
I need to change tempo ( while keeping pitch) to a whole group of files recorded in one song.
Each is a long file fitting the whole song ( 5'40"), no loops at all.
I must slow them down of 2 bpm ( from 85 to 83).
How can I do it ?
I can use Audition, Acid and Sound Forge.
Thanks for your help, I really don't want to do them all again !
luca

[JGriffin]

One way to do it would be: in Acid:

Create a new Acid file. Set the tempo to 85 bpm.

Import all of your tracks. Line them up and make sure they play back fine.

Set the tempo to 83 bpm. Play the song down to make sure it sounds good and doesn't drift, etc.

You can now either export the tracks as a mix, or by selectively muting and exporting, you can individually export to create new mixable tracks to put into another application.

Have fun!

[chris harris]

just 2bpm?!?

[apropos of nothing]

You could also use sound forge to pitch shift the whole track, which'd act like varispeed on a tape-deck.

I will say that the most recent Acid's BPM-shifting engine sounds pretty decent, and with a small shift, like 2bpm, you're not going to lose *that much* quality. the Beat-mapper wizard is pretty happenin'.

[unguitar]

Hi, I tried to export the single audio files and re-importing them in a new acid song set to 83 bpm.
Unfortunately slowing down of just 2 bpm has brought to an evident warbling to the recorded sounds.
It may be because most of the sounds have long sustained notes.
The more rhithmic ones have slowed down well, but these are just 2 in a song composed by 15 files...
I am afraid I will have to re-do them all.
Any other idea to try ?

thanks a lot !
luca

www.unguitar.com

[apropos of nothing]

I'll say again: If you don't need the pitch to be the same: use the pitch-shifter in Sound Forge. Make sure the "preserve duration" checkbox is not selected. Use highest quality. You want the length of the track to be 85/83=102.409639% of the unprocessed orignal.

[UXB]

There are many ways to do this, but each with its own set of artifacts. Tools like serato pitch and time used to be one of the better ways, but there are many options. I'm not too familiar with pc based tools for this, but don't be discouraged if one program doesn't do it well. There are usually many parameters that can be tweaked for better results.

Sometimes software designed to align audio to video can have good algorithms as well.

Best,
H

[unguitar]

I'll say again: If you don't need the pitch to be the same: use the pitch-shifter in Sound Forge. Make sure the "preserve duration" checkbox is not selected. Use highest quality. You want the length of the track to be 85/83=102.409639% of the unprocessed orignal.

Actually I need to keep the pitch and change the tempo, I checked the SF pitch-shifter and it seems to me it doesn't allow to affect duration without shifting the pitch ...

About other sw, I wanted to check if it was possible with the ones I have ( Sound Forge, Acid and Audition).
Thanks for your help.

luca
www.unguitar.com

[JGriffin]

Hi, I tried to export the single audio files and re-importing them in a new acid song set to 83 bpm.
Unfortunately slowing down of just 2 bpm has brought to an evident warbling to the recorded sounds.
It may be because most of the sounds have long sustained notes.
The more rhithmic ones have slowed down well, but these are just 2 in a song composed by 15 files...
I am afraid I will have to re-do them all.
Any other idea to try ?

thanks a lot !
luca

www.unguitar.com

1) go back and re-read my directions. first you put them in an 85 bpm song, then adjust the tempo. Do not import them into an 83 bpm song, that'll just confuse matters.

2) unfortunately, Acid does tend to screw up small tempo changes, which is odd as they're usually pretty good at large tempo changes. So 2 bpm change is risky in that program. Try 82.5 bpm (and other variations around the mark) and see if some other approximate fix works. Of course, if it absolutely must be 83 bpm, I dunno what to tell you.

[obermorph]

Find someone who is using PT 7. Import the tracks, and set the audio tracks to "Tick Based" Then, as long as it is all aligned right, you can set the tempo to 83, and all of the audio will change with it.
Supposedly with very few artifacts as it moves each sample relatively small values based on the Bar/Beat/tick values of the session.
I have not used it myself, but it would be the easiest way with the fewest artifacts. Seriously check it out.
r