Why does consolidation &or bouncing tracks=loss of sound quality

[John Kurzweg]

Ill definetly try spectrafoo and a few other tests(scsi or system-good suggestion)to try and get to the bottom of this but im not sure using the same computer to test this stuff is the wisest choice-I wonder if it could be a clock issue of the motorola chips in the mac or in the digi cards?-The time adjuster and flip phase method is definitly the more scientific way and is how i always do this test(Just ask my assistant who I drive crazy with my meticulous "that test is not valid because we didn't etc....)-But theres still something going on-If enough tracks are going I can really hear this.One more test that may open some ears(This test only takes one track to hear)-buss a track with a plug-in(the last one I did this with was McDSP Analog Ch 2)and rerecord it to a new track.Now match volumes and pans etc.Solo the original with the plug-in on and then solo the new track(with the other one muted of course)Flip back and forth a few times.
To quote my assistant after he picked the original EVERYTIME from across the room, "I dont even want to think about what that means"
P.S.(I had 2 other bounced tracks up so it would'nt be a 50/50 proposition)NOW------Would rerecording from a buss improve with a better clock?

[mpr3]

Well, if I understand jitter correctly (I do not assume this to be correct), the re-recorded bussed track could be a bit for bit copy of the original track, but at the same time could have more jitter than the original. Thus, resulting in perfect null cancellation when inverting one against the other, but having an audible difference resulting from the jitter.

If you were copying the tracks or duplicating them like you would data files, the jitter would be the same in both tracks, but since you are re-recording the audio in-real-time, the system clock may come back into play. The question then would be: why do consolidated tracks sound different than the original pieces since the merging process is not time dependant?

Again, this is all amatuer speculation, and in no way am I stating facts here.

[roberts]

I wonder if you dulicate a Micsrosoft Word file if you loose any of the letters.

[2064]

John, not saying you dont hear anything but you could just be a little paranoid. What if the fade files changed the audio region (well they actually do) even the tiniest little bit that file could be perceived as an audi quality issue. I cant say I have ever noticed this. Even if I did notice it after reading this thread it wouldnt bother me to much.

Rememebr when you recorded to ananlog tape? Did the signal ever come back the same. It never did with me it was an instant reach for the HMF pots as sson as the signal was coming back from tape.

will have a check later though [img]images/icons/cool.gif[/img]

[s2n]

I wonder if this has anything to do with the sample rounding bug. [img]images/icons/confused.gif[/img] You might wanna try and x-fade & consolidate while in SLIP mode. Then perform tests on the newly consolidated file. It might be worth a shot. You might also be doing double-dithering...dither when fading/x-fading and output dithering.

[narcoman]

check that your not bouncing in 24 bit but with 16bit dither on in the bounce. I've seen loads of people do this.

[narcoman]

Oh, And if your dithering AT ALL your introducing a change.

[Rob Aubrey]

HI

I recently did a project that needed editing and consoldating on a stereo and 5.1 surround file. I sent it off to a dvd production house and when I got the files back I could have sworn that they were different.

I eventually did theis PHASE invert trick on the files against the original and ............???


Guess what they cancelled out absolutely, It was in my imagination!

Sometimes the 'old'ears play tricks on me, but I would like to hear if anybody else has come to a conclusion/
ROB

[2064]

John, I have since tried a listening test and I hear no difference. I dont have the best monitors so there is always a possibility you are hearing something I´m not?

[orbital]

John, i recently worked on a project using Logic Audio, i did all my midi programming and then tracked the results into Logic 24 bit, 44.1, it was all synth based music, i liked the sound i was getting in Logic but i the wanted to try mix in Protools, so as to make it easier to import, i bounced each track from a common start point ,ie bounce starts at bar 1 ends bar 150, then i imported the the bounces into Protools, the results where a suprise, the track seemed to loose definition in the bottom end, the mix using bounces sounded "thinner" to my original Logic Audio work mix using first generation tracking, i know exactly what you are saying regarding the whole bouncing issue.