Advanced Pro Tools/Mixing Question

[robertstj9]

I've got something kind of strange happening and I can't quite pin point what it is. Like normal I am mixing in stereo and everything sounds like I want it to. But when I hit the mono button on my 002 everything down the center is just fine, but the stuff panned left and right are significatly reduced. At first thought, I was sure it was phasing issues and it was something I just need to work on in the mix. But when I listened more closely, I realized that it really shouldn't be phasing because they are completely different tracks (guitar 1 is all hard left and guitar 2 is all hard right). I could understand phasing if it was just overheads disappearing, but it also did background harmonies and toms the same way. So anything not right down the center seems to be loosing volume. It also does the same thing when I burn my mix and play it through a mono source in a different room. I also went back and checked old mixes and they were doing the same thing. This is why I think it has something to do with the summing and bouncing in Pro Tools. I am pretty proficient in Pro Tools, but don't remember coming across a setting that changes the summing and bouncing options. Please let me know if you guys have any ideas. Thanks

[sw rec]

That really does sound like a phase issue...have you tried inverting the phase on one of the instruments to see if it solves the problem? Any number of the rtas plugins hyave a phase reverse button.

[robertstj9]

I tried flipping the phase on the guitars (which is the main problem), but this did nothing because they are completely different signals. One is a rhythm guitar and one is a lead. When this didn't work I also tried by putting every single track down the center, and this was actually a decent mix. This is why I get the impression that Pro Tools drops the outside channels down in volume when it sums and bounces the mix. Am I just crazy?

[Kris75]

What is your monitoring chain? I had this problem once working in a room that was not acoustically treated, and using the passive version of the Tannoy Reveals. I narrowed it down to the amp we were using to drive the speakers in combination with the dimensions of the room (although I did not like the reveals).
Maybe that is an option as well. Remember that phase is something that happens in nature not just in circuts.

[Aussie Scott]

One mixing technique I've heard many people use is to do most of the mixing in mono (with the mono button in) and occasionally flip out to stereo to see how you're going and to chack any panning effects etc.

The theory is, if it rocks in mono - it'll really rock in stereo. Also in mono you find your phase problems pretty quick.

Scott

[robertstj9]

I use some Event TR8 active monitors in a decently treated room. However, I do know that is not the problem because I have used a couple of different mono boom boxes which I took a burned cd mix to different rooms. I would think this would rule out the monitoring being off.

As far as mainly mixing in mono, I have gone back and tried that, but I find my self having to adjust the levels by turning down the stuff panned to the left and right once I throw it back into stereo. And since almost all sound systems are stereo these days, I would rather have a good stereo mix than mono if I have to choose.

[daeron80]

That's absolutely normal. Most mixers give more gain to the total mix when a track is panned center than when it's not. With PT, the difference is 3.5 dB from Center to hard L or R. Once your pans are set about where you think you'll want them, and the overall mix is in pretty good shape, that's the time to get the final balance while monitoring summed to mono. When you go to stereo, it will still sound great. But if you tweak the balance while monitoring in stereo, especially if you're mixing through headphones, it won't sound right summed to mono.

The fact that you noticed probably means you have good ears.

[tapani]

That's absolutely normal. With PT, the difference is 3.5 dB from Center to hard L or R.

It's called Pan Law or Panning Law. Do a search here or Google. I haven't looked at my meters, but hearsay I thought said it was 2.5dB. In HD someone said they changed it from 2.5dB to 3dB, so presumably Digi may make this change for PT LE too.

Tapani

[daeron80]

I haven't looked at my meters, but hearsay I thought said it was 2.5dB.

That's correct of the inverse situation, which is how it's usually stated. If you ask about the pan law of a mixer, the figure given will be the difference in level in one channel between a signal panned hard to that channel and panned center. That figure is deceptive, though, because we don't listen to just one channel, we listen to both.

In PT, the center is 2.5 dB down in the center. That means if you have a mono track panned center, its level in the stereo bus - in two channels - will measure -2.5 dB with reference to its level as a mono track. Since the combined level of the two channels of a stereo bus is double that of a mono bus (i.e., +6 dB), that means the centered track is delivering 6-2.5=3.5 dB more level to the stereo bus than it would if it were panned hard L or R.

In HD someone said they changed it from 2.5dB to 3dB, so presumably Digi may make this change for PT LE too.

Uh oh. No, they haven't changed it for LE. That would be kind of nasty to move a mix from LE to HD or vice versa and find that your levels were off. I hope they haven't really changed it.

[robertstj9]

That helps to know that I'm not crazy. I've heard of pan law before, but don't guess I ever really thought about it too much. So with that said, how do you create a stereo mix that also sounds great in mono? In my case, the guitars (which are panned hard left and right) sit right where I want them to in the stereo mix, but in mono they almost disappear. I guess I'm being really picky, but that's what I am paid to do.