Most of my original songs were recorded on tape and transferred to digital. The BPMs are not exact. I'm having difficulty syncing loops to these songs. I use ACID 6.0 (don't laugh) for this task. I've tried the Beat Mapping feature but it doesn't work for me. So I use a trial and error process. I manually reposition the loop and manually adjust the BPM rate until the song and drum loop are in sync throughout the entire song. In most cases the BPM rate is carried out to two or three decimals i.e., 120.275 BPM.

Okay. Two questions:
1. Can I set the BPM of my songs (in my DAW) to a whole number without sacrificing the sound quality?
2. Is there a software that will detect the BPM down to decimal points?

 

I would try a more advanced DAW, look at youtube videos that explain how the top DAWs achieve what you want. Some can do it automatically but I forget which (I had the same problem a while back).

 

Thanks. I also use Reaper, but mostly for it's MIDI features. I'll check out it's BPM features.

 

It's not really about what you can do, because you can basically do anything you want. The question is how much degradation of your files are you going to get as a result of the way you pick to do it.

You should be able to get a bpm counter plugin, or there is probably one in your DAW. If you leave the session at 120bpm, you load the file with no time correction done to it during import. In Logic, the stock bpm counter only goes to 1 decimal place. But it gets it so close anyway, that some .1275 margin of error will be your variance. Something under .1 of a beat is such a small variance, that any timestretching (time compression or expansion) will be so negligible that you will not hear it at the bpm level, never mind the audio quality difference it causes to fix it. Your DAW will do those calculations down to the sample accuracy anyway, not the bpm.

If your files have bpm variance just caused by tape, it will not be that much. If the original clock was something wrong, or a band playing out of tempo all over the place; is where you will run into problems.

 

Last edited: Aug 11, 2024

I get asked this time & time again.If you are any good at looping or djing the bpms do drift! as they say today is to tap to sync on usb decks ..which i had no option using technics 1200s back in the day but here's a site for key & bpm but its been a while! Acid pro is more capable of doing the job as i used to do mix cds onit
https://tunebat.com/Analyzer

 

Last edited: Aug 11, 2024

Try it out. Theoretically, there is always a degradation in quality when the audio has to be time stretched, pitch shifted, etc. It just depends on whether you can hear it.

Celemony's Capstan can remove wow and flutter from tape recordings and bring the audio back to the original tempo. Melodyne can detect the tempo and create a tempo map to use in a DAW.

 

How I would do it in Ableton is. note the exact time the original lasts on tape. Then once you have imported it to the digital realm, insert a start point then go to the very end of the song and place an end point. Now drag the end point to the exact timing of tape.

That's it.. done! You may not even need to warp it (although if there is excessive wow and flutter on the tape? Then yes you might!)

You should be able to do that in ANY DAW. I say should, because I've only ever done this in Ableton!

As for degradation, it is negligible!

 

Do you still have your decks?

 

When you transfer a track to a DAW (tape machine > DAW), then insert start/end points to the recorded track, the time dispayed between the two markers is exactly the same as the original track played by the tape machine (the contrary will be illogical, at least to me).

So, unless I've missed something, where are you're going to drag your end point other than the exact same spot you've already inserted it?

 

This is even easier if you are using a digital file, like from YT. A lot of the time, you will end up with empty space at the beginning and end of the file. You microscope zoom in to the very first dot of waveform start. Chop it, delete the silence, and pull the entire track all the way back to 0. Insert your BPM Counter and play it long enough to get the real bpm of the file. You change the DAW project tempo to the real BPM of the file. Cut the tail the same way. Instead of leaving it at some "almost perfect measure length", and warp it the tiny bit it takes to get it to a perfect bar length. So now you have 192 bars at say 118 bpm. Change the project back to 120 and drag it to the exact same measure length (timestretch it). Bounce the audio out as your new 192 bar long, 120bpm file.

Open a new project at the new corrected tempo. But when you reimport the file, you set your DAW import option to not only Align the start and end points of the sample; but set it to Align Bars and Beats. It does not just stretch the file, it aligns all the downbeats within the measures.

If you chop up old funk and disco stuff from vinyl, it will save you a ton of time correction manually to account for drift. Then you stick the whole track into RipX to separate it using the real bpm, before you even start chopping. 5 minutes of prep work will save so much time cutting, and way less damage to the audio. Melodyne might be a little faster, but you have to use Melodyne. No thanks.

 

Last edited: Aug 11, 2024

1. Yes, of course there will be distortion proportionally to the difference from the original average BPM.
2. Yes, most of DJ sw can do that, for daws, it depends.

Yep the worse thing was not the speed but the pitch cange, that was immediately perceived as you touched the pitch control (I love the time/pitch stretch of sw today).

Well, yes and no.
If the track is diamond cut on tempo, there will be no problem, but if shifts up and down (many track from 70's will do) you'll have to set warp marker to bar 1, on the last bar and every some measure add a warp marker to realign it, or you could have some sync problem with daw BPM here and there.
BTW I experienced that in Ableton, but at last I succeded in perfectly realign the track.