Bounced midi to audio doesn’t null test?

Just curious if anybody has run across this. Not using any plugins, just a logic synth. After bouncing, the audio file doesn’t even come close to canceling when the polarity is flipped. Anyone know why ??

bounce-in-place? or bouncing out of logic? does the synth have any chorusing? are there any random elements in the sound? does it sound bad on it's own? out of time? out of key?

 

if it's important to figure this out, good luck; there's a great community here to help. but i have to say... i've never tried this, am too busy making music....

 

EDIT: i have never bounced-in-place anything that didn't sound exactly like it should (but of course, am only using my puny human ears...)

Yea, bounce in place. I just have a habit of checking regions I bounce in place with null testing to the source. Only takes a couple of seconds and I like the piece of mind. Anyways… thanks for taking a break from making music to chime in.

ok, but again... any chorusing, or random elements in the sound? that can affect things... (am not trying to be difficult... i just can't help it usually)

You can Freeze the track prior to bouncing. This will ensure any random elements (freewheeling LFOs, round robin samples etc.) play back exactly the same every time and thus the null test will work correctly.

Like has been said, synths often involve pseudo random things like global LFOs, reverb, modulation, chorusing and other non-repeatable things so they often won't null when you record them multiple times. This is not a problem.

 

If you want peace of mind that nothing's broken, take a synth sound, one oscillator, filter fully open, turn off all modulation and FX so you're left with a raw sawtooth. Make sure it's phase is retriggered on each note, as otherwise, free-running oscillators also mean duplicate recordings won't null - once you do all that, the simplest of simple cases, your files will likely null if you've done everything correctly. But you've really gained nothing from that exercise really, so I'm not sure what the point is.

 

Why did you expect it would null? Why does it matter? Life doesn't null....

I'd suggest not using a synth but a sampler for this.

A couple of weeks ago I did this with Ultrabeat and the results were weird, to say the least. It depended on where the regions were located in the song relative to the play start. Logic needed around two measures before the regions; then it would null completely. It's as if Logic needs a certain amount of time to "find its groove", so to speak.

Consequently having regions starting a measure 1 never did null for me. Moving those regions two measures (and starting playing from Measure 1) did null.

My guess is that it's not the bounced regions that are a problem here (if I remember correctly bouncing a region twice would null the bounced material against each other) but the playback of the original MIDI/instrument material.