Quantizing is Degrading the Signal

[Cayce]

I have a basic piano track, recorded with a Yamaha CP40 audio output (no midi) that needs just a slight bit of quantizing, mostly only whole-note markers, a few half-note markers. Because many of the transients are intentionally off-beat, I began with the quantize grid setting at 1/8 note, then removing unneeded markers. The adjustments were extremely minor, but necessary, so there wasn't much in the way of stretching or compressing. What I'm getting as a result is a warbling of the sustain decay between transients of the piano signal, almost a breathing/pumping effect. To get around it, I'm having to quantize manually, setting my elastic selection to Polyphonic, the view to Warp, and manually inserting markers, avoiding any automatic processing. Even that, though, has a slight degrading effect.

Is this typical, or am I missing something? I've found a few of what I feel are good tutorials on quantizing, but would be open to any other known resources or suggestions.

Attached is a screen shot of my settings.

Thanks.

[_JJ_]

If you can't simply have it replayed a bit tighter by a human being ... I would suggest moving what needs to be moved manually. Piano, in my experience, is difficult to nudge around because it has so many shifting overtones all following a single dynamic curve from striking the note until the following notes are struck. It's hard to make any crossfade in that decay which won't "pump" because the waveform is so complex.

But if you're careful you can shift the entire note or chord, make an edit at the beginning of the next attack, crossfade, copy / paste / trim a few db to extend a note, etc. Very tedious work but the results would likely be better than asking the computer to do it for you. IMO.

[albee1952]

Agree with JJ. But you might try this:
Go through the performance and separate clips where adjustments are needed. Then use the X-Form algorithm. X-Form is the cleanest(least artifacts), but it renders the entire file for each adjustment. By working on smaller clips, the render happens much faster.

Next time, track the midi. If you really like the sound of the CP40, its easy to send midi back to it, once the midi is quantized to your liking I used a Motif es8 for years and would almost always track both the audio and the midi for just this kind of scenario

[climber]

Originally Posted by albee1952

Next time, track the midi. If you really like the sound of the CP40, its easy to send midi back to it, once the midi is quantized to your liking I used a Motif es8 for years and would almost always track both the audio and the midi for just this kind of scenario

I do this all the time

[Cayce]

Originally Posted by albee1952

Next time, track the midi. If you really like the sound of the CP40...

Yeah, I actually did build a MIDI track and have it fairly well composed, but was trying various virtual piano instruments, all of which came up short. Actually, sounded like crap. I've spent so much money on a half-dozen or more virtual pianos—Kontakt's Vintage Keys, The Giant, The Maverick, The Gentleman, then Pearl Concert Grand by Impact Sound Works—and can't get any of them to sound anything close to the demos, no matter how much time I spend dialing in the controls. I get a nice recording of the CP40 audio output, but haven't tried sending the MIDI back through it, mostly because I assumed there would be latency issues. I'm going to give that a shot.

I also like what JJ had to say : "If you can't simply have it replayed a bit tighter by a human being...", which is my ultimate goal, to reduce the need for quantizing at all. I'm more guitarist than pianist—though coming along—and I'm thinking the worst case scenario might be to set up the MIDI as close to perfect as I can get it, printout the score, and take both to a seasoned pianist to record. The project, though, is a 12-minute video & soundtrack I composed as a memorial for my 26-year-old daughter who I recently lost, and I feel the need to keep all performances as personal as possible.

Thanks to all for your input... helps tremendously.

Cayce

[nednednerb]

Hi Cayce,

You mentioned you "assumed there would be latency issues" with the CP40.

In my experience there could be an inherent system delay and the MIDI might be slightly out of sync with the audio when you record. However, after both audio and MIDI are recorded, if the MIDI is timed/quantized, then the following is probably valid:

When you output MIDI and re-record the CP40, the recorded audio might also have a bit of latency. The solution might easily be shifting the re-recorded audio (the whole file) to the left by the amount of latency. Ultimately, this takes way less time and fuss than the manual edit of the initial or unquantized audio.

Shifting manually any offending midi notes and re-recording will sound PRO and take less time, I think.

[loopzilla2]

Cayce,

We also lost a daughter awhile back. So sorry you have to go through this too.

Albee's suggestion to cut sections and only quantize offending parts is a great one. That will reduce the quantizing artifacts a good bit.

If you want perfect audio with no artifacts, consider cutting the audio at the offending phrase and simply moving that chunk in time. Don't know if that works for you, but it's what I do when quantizing artifacts aren't permissible (quiet piano passages, drums, acoustic guitar). Beat Detective is amazing for these moves. Use crossfades as needed.

Lastly, I ended my search with Ivory. Didn't want to pay the money, but it's truly worth every cent to me. I have all the ones you mentioned as well, and you're right - there's something missing. Hope all this helps. Here's to making it through the next season of life - Massive Cheers to you and your family.