I use Audacity to correct the speed but now I've a doubt I used it in an uncorrect way.

Up to now, I used the pitch intonation, which means that I decrease or increase the key-tune of the track of a semitone or a tone, with the result that the length of the two tracks are the same.
Example: HTW in A can be corrected to G but last 4 minutes in both versions.

There is the alternative solution, i.e.: to change the speed.
In this case there's a modification of the key-tune but also a correspondent modification of the length of a track.
Example: HTW in A last 4 minutes and corrected to G last 4,30.

What is the correct approach?



Edited 1 time(s). Last edit at 2009-05-23 13:10 by straycat58.

If you change the key, the length should change.

Forget Audacity and try to get Sonic Foundry Forge. If you want quality, you will have to pay, but Forge is a fantastic software.

Tks Haristone. Hence I messed up all my past works. (shit!)

Sound Forge is good but older versions can't cut on sector boundaries, I don't know if newer versions can do this.

If you don't know what this means consider a film that you want to splice. You will cut the film in between individual frames before splicing, you don't cut through a frame. It's the same in digital audio, there are frames or 'sector boundaries' & cuts should be made @ these points not just anywhere in the audio file. You can usually get away with it but in some cases you will get an audible click @ the join.

Cooleditpro2 can cut on sector boundaries but they call it 'Snap to Frame'

.....use Audacity to correct the speed.....used the pitch intonation.....alternative solution, i.e.: to change the speed.....

if you wanna correct the speed, you use the alternative change speed option, i guess!

speeding up too much, mj will sound like micky mouse.
when you lower the speed very much, he will sound like my granddad: slow with a deep down voice.
meaning to say: when you have the correct speed, you've got the correct key, in the right time: the way the music was meant to be.

if you want to change the key, for whatever reason, you use the pitch: changing the pitch will not affect the speed of the piece, as you experienced.

Let's say that most of the recordings I worked on were a semitone higher.
Therefore I just corrected the pitch a semitone lower leaving the tempo same as the original.
But I understand that I had to change the speed, meaning adjusting the tempo.
Not a big problem but, anyway, I made a mistake.

I do Linedancing, straycat, where we never make mistakes, we do "variations"

I use a cd player designed for dance instructors which gives a wide +/- pitch/speed correction. I might be being stupid but I don't see how you can speed up/slow down recording without affecting the pitch?

It's a big assumption but I copy whatever the source is onto a CD, play it on the above CD player and compare individual versions of a tune with a version I believe to be correct pitch wise - usually something with some clear sounding chords: Gimme Shelter, Ruby Tuesday, Love in Vain, HT Women are all good examples. If you like I "tune" by ear and generally it seems to work very well. Once I'm happy I then make a master copy from the speed corrected source on to a high end hi-fi audio CD recorder.

With vinyl sources I have a deck with speed adjustment and use a similar process.

I've had some quite pleasing results doing this - for example whilst the VGP 1971 London Roundhouse disc is the correct speed, whatever process they used to attempt to nonoise/de-click kills the sound. A speed-corrected vinyl original sounds much much better! As for CD's, a typical example is Pignose's St Paul 78 which runs WAY to fast and hugely improves when speed/pitch corrected.

I should say that in my opinion, whatever the imperfections of some of their old tape/vinyl transfers, VGP/DAC generally get the speed/pitch spot on, and a lot of times do a really good overall job - Essen 70 or Charlotte and Washington 72 for example.