Help! Outboard gear causing phase issues

[Shellacattack]

I'm running my drum mix out to my ART Pro VLA II for parallel compression. I know there'll be a slight delay, so I've been attempting to compensate for that after I record it by nudging the track and lining up the waveforms. No matter what I do, I can't seem to get it in phase with the original drum tracks. Of course the compression will alter the waveforms, but it seems very odd that it's phasey every way I nudge it.

I tried figuring out how many samples it was delayed by by running a quick test sound out and back, but that didn't help much.

I can bus the same drum mix over to the same stereo track and compress the crap out of it with the BF76, and record that back in, without any issues. In fact, the waveforms are still not aligned when I do this, but they also don't sound out of phase. When I attempt to align them, they do sound out of phase.

What the hell am I missing?

[RodC]

You are just aligning the wave forms for one freq, (Really 2 freqs that are very similar). If you pass a signal through something and the "tone"changes then its most likely affecting the phase, and it will affect each freq differently. This is how most EQs work, you are just changing the freq of the signal in a selected area so that adjoining signals amplify it or cancel it out.

In theory you could correct a perfect delay caused by a piece of gear by nudging a track, but you wont be able to correct for multiple freq shifts by moving the whole track. When you nudge the track so things line up at say 200Hz, your highs may be off. (Resulting in the sound of Comb filtering) If you line up things at 3K, the lows may be off a bit, hurting the bass or propping up unwanted low freq sounds.

[T-rex]

A couple of things. 1. What program are you using? 2. Have you checked your wiring to be sure that one of the two stereo or both cables are wired correctly? Honestly probably not a big deal if you bought the cables but worth checking just in case.

You should put a really sharp click (like from a click track) in front of the drum track and then when you run it out to the VLA and back in you will have a definite point to line the two up again, as opposed to a wave which has been altered by the compression. The other thing you could maybe do is run the drums through twice. Once, compressed all to hell or whatever and once through the same exact chain but with no compression. Then those two tracks are going to be lined up to each other as close as you are going to get and you can see what the issue is or just use those two tracks instead of the one original and one compressed.

I thought even PT had delay compensation so I am surprised you are having that much of a phase issue but nudging stuff always freaks me out a little. Sometimes its perfect and other times a slight nudge in any direction is just phase city.

[T-rex]

BTW, nice avatar!

[chris harris]

You never mentioned if it sounds phasey and weird BEFORE you start nudging things.

[farview]

Have you tried to reverse the polarity of the compressed tracks before you line them up? You might have some wiring somewhere along the way that reverses the polarity.

[Nick Sevilla]

You never mentioned if it sounds phasey and weird BEFORE you start nudging things.

+1

[Shellacattack]

Thank you for all the replies! Here are the answers to the posted questions:

1. I'm using PT M-powered 8 (w/ Delta 1010)
2. Checked all my cables (also, they're fairly new)
3. Yes, it sounded phasey before I began nudging it.
4. I did not try reversing the polairty of the compressed tracks because when looking at them, they appear to be in phase with everything else, just delayed.

So, to make this whole story better... I read everyone's posts, I open up the session and record a quick click to the bypassed ART VLA, and check it with the original click. It shows exactly what my test yesterday showed, which is that going out to the VLA creates a 2-3 sample delay.

SO, I take the same track I worked with yesterday, check that it's still phasey in it's original position, then move it 2 samples earlier. Now everything is in phase. I don't understand what the hell happened, it must be user error, but I spent about 30 minutes yesterday nudging sample by sample, both earlier and later... and it didn't EVER get in phase. I feel like I'm taking crazy pills.

I decided to record a newly compressed track of the drum mix, and this one also easily moved in phase. So, sorry to waste your guys' time, but I appreciate the responses.

And T-rex, thanks for the avatar comment! Are you a Slint fan as well?

[RodC]

I used to use the 1010s, nice units. I know this is not your issue since the polarity is correct, but you should be aware of this:


Delta 1010 Polarity issue
Tuesday, 22 January 2008 23:02
I have just noticed that when I switch my input level from +4 to -10 that the signals phase is inverted.


http://beyondsanityproductions.com/inde ... &Itemid=28

[T-rex]

Yeah, I have lived in Louisville since the early 90's so I was big into the post punk scene here, as a fan. I have a bootleg from twice told coffeehouse somewhere where they cover cortez the killer along with their regular set from waaaay back. If you are interested and don't already have it, I will try to track it down.

[Shellacattack]

I used to use the 1010s, nice units. I know this is not your issue since the polarity is correct, but you should be aware of this:


Delta 1010 Polarity issue
Tuesday, 22 January 2008 23:02
I have just noticed that when I switch my input level from +4 to -10 that the signals phase is inverted.


http://beyondsanityproductions.com/inde ... &Itemid=28

Yeah, while googling my issue, I randomly came across a post from you on a separate message board on this subject. Did you ever determine if it was intentional on the part of M-Audio?

Yeah, I have lived in Louisville since the early 90's so I was big into the post punk scene here, as a fan. I have a bootleg from twice told coffeehouse somewhere where they cover cortez the killer along with their regular set from waaaay back. If you are interested and don't already have it, I will try to track it down.

I'm definitely interested! Does their regular set include anything off their albums, or is it completely different stuff? That'd be very cool to hear.

[RodC]

I don't think it was intentional, I think it was a design overlook/flaw that they just never corrected.