How to Slow Down Backing Tracks for Practice and Avoid Dropouts

[Jamie Rosen]

I use Cakewalk to help practice and record guitar over backing tracks from NowYouShred (amazing tracks) and often need to slow down the tracks until I get my chops up.  But, I'm having an impossible time figuring out how to successfully do so on CW.  I found the option of using audiosnap and "clip follows project," and then adjusting the BPM downward up in the counter area.  This works for about 5-10 seconds, until I get a dropout error.  It's always #1, which tells me to change change the buffer size, but that has not been successful, even when I move the slider all the way to "safe" (and it creates unworkable latency).  I ultimately resorted to trying to slow the tracks before importing to CW using https://audiotrimmer.com/audio-speed-changer/, but that's a real pain.  So, does anyone have any genius ideas?  I'm surprised this is so hard, since slowing audio while maintaining pitch is such a common tool across so many platforms (youtube, slowdowners, etc.).   I have a pretty powerful laptop that I work off of (Dell G7 gaming laptop), so it's hard for me to believe that my computer is too weak/slow.  I use the iRigHD as my interface, so I'm not sure if that may be the issue (I could use another interface if needed).  Finally, if CW is just not a good fit for this sort of guitar pratice and recording over backing tracks, I'd love to hear other recommendations for a windows laptop.  I just need a very simple mutlitrack recorder/DAW (I switched to CW after Cubase was making me crazy).  thanks!!!!

[57Gregy]

I'm sure there's more than one way to do it, but I just tried a method in CbB, the one I would use for its simplicity.
Assuming the tracks are all audio, I would bounce them down to a single stereo track in the same project. Do that by selecting all the tracks you want, going to Tracks>Bounce to Tracks and selecting busses as the source, then Master bus. Also assuming the tracks are going through your Master bus.
Once that master track is rendered, select that track only, then go to Process at the top, then Length. I did 120%, which slowed it down quite a bit. So, now you have a slow track and your fast track(s) all in the same project. Solo whichever one you're working on and when you're through, you could delete the slow tracks if you want.
If they are MIDI through soft synths, you would have to render the MIDI to audio first.

Welcome to the forum.

[John Vere]

You can most certainly do what you are doing with out issues but a few things to think about. 
1- Make sure the audio clip is set to Musical time in the clip properties of the inspector 

2- Don’t overdue it. It can only take so much of a change or it will barf. 3. Find a midi file of the backing track and you can slow that down to zero. 
4. Cakewalk is a multi track Audio recording DAW. It is not a DJ software app those are designed to do what you want. 

[Jamie Rosen]

2 hours ago, John Vere said:

You can most certainly do what you are doing with out issues but a few things to think about. 
1- Make sure the audio clip is set to Musical time in the clip properties of the inspector 

2- Don’t overdue it. It can only take so much of a change or it will barf.

3. Find a midi file of the backing track and you can slow that down to zero. 
4. Cakewalk is a multi track Audio recording DAW. It is not a DJ software app those are designed to do what you want. 

thanks for the input.  I checked and all clips are set to musical time.  As for overdoing it, I would get dropouts even trying to reduce speed by 10%.  As for finding midi file, that won't do, as it's not simple backing track I'm using; it's a multitrack that I disaggegate in the CW DAW, which allows me to not only play over the backing track, but also to swap out my tracks for the original (e.g., I lay down my own rhythm guitar track and mute or pull out the original; I add my own lead track, etc.).  So, that's also why I need a multitrack option like CW and not a simple DJ app.  Any other clues would be appreciated!  thx!

[John Vere]

Well 10% change in tempo should work. Just last week I did this to a project. I have developed arthritis in my right hand so it hurts to hold a pick. 🙁  I went from 95 BPM to 85 BPM and recorded the lead part .  
The project was mostly midi  but there was 2 Rhythm Guitar parts as audio and a scratch vocal. 
It didn’t work the first time because the Guitar parts were edited so I exported them and the vocals as stems @ 48/32 and brought them back in and applied audio snap clip follows project. Set BPM to 85. No problem. I recorded the lead and reset the project to 95 BPM.  No artifacts I can hear.  
I wonder if you export those tracks like I did?  What do they show as when you look at them in Project/ Audio Files ?  

The other thing comes to mind is buffer settings. I run at 256 on a Motu M4. 

[Jamie Rosen]

On 3/14/2022 at 9:18 AM, 57Gregy said:

I'm sure there's more than one way to do it, but I just tried a method in CbB, the one I would use for its simplicity.
Assuming the tracks are all audio, I would bounce them down to a single stereo track in the same project. Do that by selecting all the tracks you want, going to Tracks>Bounce to Tracks and selecting busses as the source, then Master bus. Also assuming the tracks are going through your Master bus.
Once that master track is rendered, select that track only, then go to Process at the top, then Length. I did 120%, which slowed it down quite a bit. So, now you have a slow track and your fast track(s) all in the same project. Solo whichever one you're working on and when you're through, you could delete the slow tracks if you want.
If they are MIDI through soft synths, you would have to render the MIDI to audio first.

Welcome to the forum.

thanks!  I tried it and it seems to work well without dropouts.  One issue/question.  I'd prefer not to group all the tracks together, because then it's hard for me to drop a track out at the end (I want to substitute my guitar part for the backing track's guitar part, after playing along with all tracks at the reduced speed).  So, is there any problem with just skipping the tracks/bounce step and just selecting all tracks and process the length to them as a group?  It seems to work well at quick try, but I thought I'd check if there's a better way to do this. thanks!!!

[sjoens]

I just did this.

1. Select all audio tracks

2. Open Clips in Inspector

3. Open Groove Clip

4. Check Stretch to Tempo (all tracks will be adjusted)

5. Set Tempo in Control Bar

6. Hit Play

EDIT: Doesn't always work as expected

Edited March 16, 2022 by sjoens

[msmcleod]

If the backing track is a single audio file, the easiest way is to hold CTRL+SHIFT to stretch the clip:



If you want to do it in an existing project, bounce the tracks to a new track and solo the new track.  You can then stretch it while you practice until you're ready to record.

[John Vere]

I like @57Gregy idea. It seems the secret is to bounce the tracks. I don’t know why this is but the only time it works is when then the audio has been bounced or exported which is the same as bouncing I guess. 
But the other 2 ideas from @msmcleod  and @sjoens might work too. 
Those ideas are not easily undone  and so you would want to do this to a copy of the track. 

 Greg’s idea keeps the original audio untouched ,  that appeals to me 

Edited March 16, 2022 by John Vere

[57Gregy]

11 hours ago, Jamie Rosen said:

So, is there any problem with just skipping the tracks/bounce step and just selecting all tracks and process the length to them as a group? 

None at all, as long as you remember to NOT save it at the end of the session. You would have to remember to Undo (Ctrl Z) after each iteration. You could also copy all the tracks and work on the copies to your hearts content without altering the originals.
I don't know if repeatedly Lengthening and undoing a track will screw it up, which is why I typically work on copies.

[sjoens]

Scratch my method. It worked in one project but in another one it did some very strange unexplainable things to the audio.