Stem separation or Melodyne issue?

[lowerfreq]

Tried stem separation for the first time, and I'm not sure how usable it is, at least how I attempted to implement it.
My friend recorded a S1 song with vox, drums (EZDrummer vsti), keys, acoustic and electric guitars. He sent me an mp3 mixdown of the song which I imported into a new project and then used the stem separation function to break it into the appropriate tracks. It had average at best separation--there were a lot of ghostly artifacts going on in certain sections. Anyway, his EZdrummer kit of choice was suspect, so I thought I would try switching kits by editing the drum track with Melodyne and then importing it into a new EZdrummer track with a different kit. Unfortunately, when it was processed by Melodyne (tried both the Universal and Percussive detection), it turned out unusable. The "blobs" or notes detected were mostly on the same (almost all crash cymbals with a stray snare or kick hit). Is this a user error by me, an issue with the stem separation, or a Melodyne detection problem?

Thanks for any thoughts...salud!

 

[lokeyfly]

.......Unfortunately, when it was processed by Melodyne (tried both the Universal and Percussive detection), it turned out unusable. The "blobs" or notes detected were mostly on the same (almost all crash cymbals with a stray snare or kick hit). Is this a user error by me, an issue with the stem separation, or a Melodyne detection problem?

Well, you tried both methods of detection, so you made good on trying Melodynes capabilities. I usually don't use Melodyne on drums, but to hopefully assist, you can copy and paste in Melodyne. Are you using Melodyne Editor, or Studio? If you're using only Melodyne Elements which is the free supplied version in Studio One, that might explain a lot. Elements is monophonic, not polyphonic. So it's not going to capture drums in any usable way. At least for re editing. Also make sure you bounce the event after you edit with Melodyne.

In the final analysis, what you stem should be quite literally what is on the track itself. Blobs aside. But it sounds like you were having difficulty editing in Melodyne and I'm not sure what you were using.

Again, my experience editing drums and use of Elements was little to zero. Other instrument, quite the opposite. Melodyne Editor does not hold me back in any way. In fact, I usually chalk Melodyne Editor up as Supernatural Voodoo. (In a good way).

 

[TDF1981]

Tried stem separation for the first time, and I'm not sure how usable it is, at least how I attempted to implement it.
My friend recorded a S1 song with vox, drums (EZDrummer vsti), keys, acoustic and electric guitars. He sent me an mp3 mixdown of the song which I imported into a new project and then used the stem separation function to break it into the appropriate tracks. It had average at best separation--there were a lot of ghostly artifacts going on in certain sections. Anyway, his EZdrummer kit of choice was suspect, so I thought I would try switching kits by editing the drum track with Melodyne and then importing it into a new EZdrummer track with a different kit. Unfortunately, when it was processed by Melodyne (tried both the Universal and Percussive detection), it turned out unusable. The "blobs" or notes detected were mostly on the same (almost all crash cymbals with a stray snare or kick hit). Is this a user error by me, an issue with the stem separation, or a Melodyne detection problem?

Thanks for any thoughts...salud!

No user error - Melodyne can’t do all the work and you need to separate blobs by hand for some stuff.

Anyway, regarding the quality of the stem separation: I think we all need to remind us of the fact that these algorithms have been trained with well-mixed tracks. Probably with tracks that are mainstream for their genre aka tracks that sound like one would expect for a good Rock, Electro, Pop etc. track.
So if you get something like a rough mix or anything that crosses those borders of popular sound mixing you will get more artifacts as the algorithm will probably not understand why a vocal is “behind” a curtain of guitar noise etc.
I would argue that having an mp3 can also lead to problems due to the artifacts it already presents when being below 320kb/s
Maybe you get better results with a .wav at 48kHz in 24 bit.

 

[lokeyfly]

I completely agree. The stem separation is going to provide separation in best case scenarios.

The Melodyne issue you mention lowerfreg, If you're trying to remove particulars from a track with Melodyne, it also doesn't work miracles. If frequencies are closely related to neighboring frequencies (drums or otherwise), then Melodyne can't properly seperate those entities from one another. If we know which Melodyne you're using, that might help tweak a little further, but dont expect a lot.

Blobs can simply end up more often than not just being residuals of a sound. Overtones, harmonics, resonance, acoustic reflections, etc. Reverb on those drums won't help either. Nor will long decays. So full removal of specific drums may often not be in the cards.

 

[lowerfreq]

Tried stem separation for the first time, and I'm not sure how usable it is, at least how I attempted to implement it.
My friend recorded a S1 song with vox, drums (EZDrummer vsti), keys, acoustic and electric guitars. He sent me an mp3 mixdown of the song which I imported into a new project and then used the stem separation function to break it into the appropriate tracks. It had average at best separation--there were a lot of ghostly artifacts going on in certain sections. Anyway, his EZdrummer kit of choice was suspect, so I thought I would try switching kits by editing the drum track with Melodyne and then importing it into a new EZdrummer track with a different kit. Unfortunately, when it was processed by Melodyne (tried both the Universal and Percussive detection), it turned out unusable. The "blobs" or notes detected were mostly on the same (almost all crash cymbals with a stray snare or kick hit). Is this a user error by me, an issue with the stem separation, or a Melodyne detection problem?

Thanks for any thoughts...salud!

Thank you both

I am not familiar with Melodyne Elements? I just use the free Melodyne Essentials that came with S1. It make sense that a better version of Melo might do the trick, but I'm not going to go there as of now. All I wanted Melodyne to do was detect the drums so I could convert them to a midi track. Separating the blobs seems like much more work than just redoing the drums altogether, so that is the route I will take. And you are correct regarding the quality of recordings... my friend isn't the most sophisticated recordist (nor am I) and he recorded in a virtual echo chamber in one of his rooms;( ... 20 ft high ceilings and no treatment. I guess I could try the wav import instead of mp3, but this song is in the nascent stages and probably not worth it. Do either of you do any drum sample replacement or augmentation over a drum vsti? I have a free version of Trigger but have never dipped my toes into that water...
Salud!!

 

[Sethares]

Hi lowerfreq, I don’t really understand the approach you are taking. Since your friend has a S1 session, why not start there? Surely it should be easier to remove/replace/augment the drums from the session file than from a mix down.

 

[lokeyfly]

Correction, Essentials ; ) haven't touched it in ages.ypu may want to step up to a more capable version of Melodyne. Just saying.

 

[lokeyfly]

if you move up to Melodyne Editor, you gain polyphonic editing (so can can deconstruct chords into their individual intervals) and if you move up to Studio, you get the sound editor. You can edit multiple tracks with the Studio version, bit I don't believe that will help you, unless your friend can provide individual track stems. Removing drums and overall sounds is not an automatic or perfected process. But it's increasingly getting better.

 

[lowerfreq]

Hi lowerfreq, I don’t really understand the approach you are taking. Since your friend has a S1 session, why not start there? Surely it should be easier to remove/replace/augment the drums from the session file than from a mix down.

Yes, that makes total sense...unfortunately, my friend bounces down his mix and then deletes the song altogether---and we've had the discussion about this before, before but he's a stubborn guy, so it's not worth the battle at this point. He's not computer savvy at all and I'm actually amazed he even remembered how to export the mixdown much less turn the machine on... oh well

"ypu may want to step up to a more capable version of Melodyne. Just saying."

Certainly an option!