time stretch
have a guitar piece that’s just too tricky to record at normal speed. i’d like to slow the song down while i record (in digital audio–not midi) the guitar solo and then be able to playback the song at normal speed without altering the pitch of my guitar piece.
i have nTracks 3.3, powerTracks pro audio 9 and cool edit pro 1.2. do any of these offer such a feature
Try practicing harder. (Just kidding.)
Yes, it is possible to do this.
You can do “Track” => “Special” => “Time Stretch” to double the speed of a track (which will also raise it an octave) and then use the n-Track pitch shift plug-in to transpose it back down an octave (and thus back to normal).
(I would start by mixing down a bed track and then doing the reverse of the above process in a new project file to create a half-speed backing track. Then you can (slowly) play your guitar to it. Then when you’re finished, just import your speedy guitar back into the original project.)
NOTE: This will suckify the audio quality of the track. Pitch-shifting never sounds normal and may create odd artifacts. Perhaps you could try doing it with a dry guitar signal and then use an amp-sim plug-in after you’ve done all the monkeying around. You might be able to get away with it in a mix; though. It’s worth a try.
As an alternative, I hear Yngwie isn’t so busy lately 
hth,
mrtoad
I can’t believe I didn’t think of this before:
If the tricky part is up the neck then you could simply play it an octave lower and skip the pitch-shifting. Anyone have a baritone guitar? 
Also, if the tricky part is only a small section of the song you could paste it into a track that didn’t have the monkey-business anywhere else and then send the whole thing through an amp-sim. I’ll bet it would be hard to tell.
mrtoad
what’s amp-sim ?
i’ve been trying to use time stretch but the only directions are the help section and it really doesn’t tell you how. could i accomplish what i want with time stretch ? if the answer is yes, i’d appreciate a “step by step” on how to use the thing.
thanks for the replies
Eyup!
Cool Edit 1.2 will do it.
Steve
I’m working with n-Track v4.05 at this point but I think the following will be pretty similar if not identical in 3.3.
First, even though “time stretch” appears to refer to an entire track, it ONLY seem to work on one complete wave file at a time.
Step 1. In the timeline click on the wave file you want to speed up or slow down.
Step 2: “Track” => “Special” => "Time Stretch"
Step 3: In the time stretch window use the “transpose” function. +12 to double the speed. -12 to halve it.
(I suppose you don’t have to go a whole octave so feel free to experiment.)
That’s it. I assume you know how to apply the pitch-shift plugin?
Oh, “amp-sim” means “amplifier simulation”. There are plugins that take a direct dry guitar signal and simulate a guitar amplifier and speaker cabinet. It’s like a line6 POD that resides in software. Examples are revalver and amplitube. See simulanalog for a great FREEWARE example that everyone (including me) raves about - the Marshall JCM800. See this discussion as well.
hth,
mrtoad
many thanks to all who responded to my post on time stretch.
mrtoad, i especially appreciate the step by step, however theres a couple of things i need to help with.
1. after i go to time stretch, is the transpose function the only thing i’m concerned with or do i need to move the slider for “new length”. it looks as though when i set the transpose value it also changes the length ? maybe i just answered my own question.
2. no, i’ve never had occasion for pitch shift until now. couple of things that “help” doesnt cover-- preamp, post gain and fft size. what should these values be set to?
thanks again for the response
fivestring
1. Yes you did answer your own question. The time stretch function works just like speeding up/slowing down a tape. The length of the wave file will increase as the pitch decreases (and vice versa). You can choose to set either the new length or the new pitch and the other will be set accordingly. I just told you to use the pitch because it’s easier.
2. Whenever you apply any effects plugin n-track allows you to increase/decrease the gain of the signal entering the plugin (using the preamp knob) and exiting the plugin (using the post gain knob). It’s useful if you want to drive a plugin harder or if your plugin is clipping for some reason; in general you should probably leave these set at zero dB (off).
The fft size (Fast Fourier Transform by the way, how’s your advanced mathematics?) refers basically to what size “chunks” of data get analyzed at a time. Larger chunks usually give better results but have higher latency. The “accuracy” control means what it says but it can turn the effect into a real cpu hog. Start with fft 1024 and accuracy 6 and experiment from there. (Warning: bumping up the accuracy too high will bring your PC to its knees.)
hth,
mrtoad
appreciate the response, mrtoad. think i’m on my way to getting this piece done.
five string