What's the deal with stereo?

[gendefect]

I feel like I don't have a very good handle on how stereo works with the Axe. I mean, I get there's a left and right output. But I feel like there are a lot of settings with regards to stereo or mono and how a given effect will be used, and some dramatically bad consequences if you get it wrong.

I tried looking through the manual and there didn't seem to be much at all about how stereo operates in the Axe (or if there is, can someone point me to where?).

So, what are some basic things you have to be constantly aware of when you're dealing in stereo. If you're going between practicing with mono and gigging with stereo (direct through a PA) what are some things you should keep in mind?

What's the best way to take best advantage of the stereo capabilities of the Axe in terms of how you program your presets?

I play FRFR, by the way.

 

[s0c9]

you should read this thread/post first..
http://forum.fractalaudio.com/threads/25470-Wet-Dry-Wet-Rigs?p=395934

Focus on Jay's responses..

 

[JWDubois]

In mod blocks like chorus, set the LFO phase parameter to something other than 0. I think classic chorus is 90 degrees. It's set to 0 by default for mono operation. It will really widen the effect. In the delay block, try the Phase Reverse parameter. Of course, try stereo, ping pong and dual delays. The enhancer block makes stereo pop too.

JWW

 

[Rex]

What you do with stereo depends on what you want to do. Just about anything on the Axe-FX can be panned left or right or anywhere in between (things like delays, amps, cabs, chorus, and much more). The panning can be fixed, or varied in real time.

There was a good discussion recently on what to watch out for when collapsing stereo patches to mono.

 

[randombastage]

Seems like stereo is good for the studio/bedroom but not so good for most stages unless the room and the PA system happen to be set up just right.

 

[Rex]

True enough. Most venues run mono; there's just no good way to get proper two-channel coverage across the room.

 

[gendefect]

Hmm, interesting. Sounds like I should mostly stick with mono and not worry about stereo too much, since I'm mostly using the Axe for gigging at the moment. When I go back to recording, I'll have to dive into stereo a bit more.

Sounds like, as far as mono goes, the output should be Sum L-->R and balance/pan should be set to center and then you should be safe, yes?

 

[Jay Mitchell]

Sounds like, as far as mono goes, the output should be Sum L-->R and balance/pan should be set to center and then you should be safe, yes?

No, that's the worst possible way to go mono, as it exposes you to all the bad phase cancellation effects. The best way is to set the output mode to stereo and just use one channel. You will then get only one channel of any effects blocks that happen to be set up stereo, which is exactly what you want. If you need two outputs with the same signal on them - for example, to send a signal to FOH and one to your stage rig - set up an output for "Copy L->R."

 

[gendefect]

No, that's the worst possible way to go mono, as it exposes you to all the bad phase cancellation effects. The best way is to set the output mode to stereo and just use one channel. You will then get only one channel of any effects blocks that happen to be set up stereo, which is exactly what you want. If you need two outputs with the same signal on them - for example, to send a signal to FOH and one to your stage rig - set up an output for "Copy L->R."

Huh, interesting. Thanks Jay, I would have never thought to do that, since it seems somehow "wrong". But I get the rationale and it definitely makes sense.

 

[s0c9]

You can run L/R outs [stereo] to FOH. Chance is the channels will not get panned hard L/R on the console so will essentially get dual-mono going to PA if they are center-panned. If you set up your presets like you would for the studio [stereo], then you do not have to redo everything for live work (and vice versa).

 

[Jay Mitchell]

You can run L/R outs [stereo] to FOH.

That poses the same risk as summing L and R inside the Axe-Fx. If the FOH sound system is not stereo, or if the sound guy does not pan left and right channels from the Axe-Fx hard left and right, the exact same cancellations will occur in the FOH console as would occur in the Axe-Fx.

Chance is the channels will not get panned hard L/R on the console

Bingo.

Bottom line: unless you know your left and right channels will be kept separate and sent to separate speakers, the only safe appoach is to send only one channel to FOH.

 

[Rex]

The best way is to set the output mode to stereo and just use one channel. You will then get only one channel of any effects blocks that happen to be set up stereo, which is exactly what you want.

Doesn't that depend on what you're trying to accomplish? For instance, if you have a patch with a stereo delay and no phase issues that you want to run mono, if you choose only one channel, you give up the echo in the other channel, and you wind up with a single-voice delay.

I see your point that there are potential phase issues when you sum to mono, but it seems it's a trade-off: do you want to "do the math" to keep phasing issues out of the patches you want to run mono, or do you want to potentially give up part of your sound?

 

[Jay Mitchell]

For instance, if you have a patch with a stereo delay and no phase issues that you want to run mono, if you choose only one channel, you give up the echo in the other channel, and you wind up with a single-voice delay.

Most stereo effects will sound noticeably better with only one channel being heard than electrically summed to mono. Stereo delay is one possible exception, but it's easy enough to convert the desired effect to a mono signal in that case. Not every "phase issue" results in complete cancellation of the wet (or dry) signal. Most "phase issues" cause unintended (and unwanted) colorations when stereo signals are summed to mono. For example, if you use the enhancer, the odds are very high that the effect of summing both channels to mono will not be a desirable one.

do you want to "do the math" to keep phasing issues out of the patches you want to run mono,

If you truly accomplish that, you won't really be taking advantage of the possibilities offered by stereo.

 

[javajunkie]

Bottom line is whether you use 2 outs, one out, or stereo/mono; a good course of action is to test your patches in the stereo or mono configurations you are likely to encounter. There are pluses and minuses to different approaches, Jay's is a great one. I usually run in stereo, so I use both outs. However, the room I play in does not maintain a very good stereo field. Even worse it is L, R, and center (center is L+R). All stereo subtleties are lost. So stuff like to amp models panned hard on each side with a small delay on one side or the enhancer sound like crap out generally. But, I can get a flanger sweeping across the room, or an panner that sweeps from L to R, or a ping pong delay.

So I avoid obvious thing that might cause phasing differences on one output(like the enhancer), and anything that might induce a small delay on only one output.
I stick the overt 2 channels effects like ping-pong delay. I check all my patches out to make sure the sound acceptable summed L+R as well as in mono.

If I were playing at a lot of different venues and had to use their house PA. I would definitely be using one output just to save a lot of headache.

 

[gendefect]

If I were playing at a lot of different venues and had to use their house PA. I would definitely be using one output just to save a lot of headache.

Ya, and that's exactly what I'm doing, playing all sorts of different venues will all sorts of different PAs/Sound Techs. So it sounds like going 1 out of a stereo output is the way to go for me, personally. I'd love to be able to make a real stereo delay sound happen, but alas. It doesn't seem like it's ultimately worth the potential problems.

 

[browlett]

Jay and javajunkie do exactly what I do. I don't ever fear creating patches in stereo. I love them. When I run my own sound live, I go stereo and it sounds gigantic. When I play somewhere that has its own sound guy (and I know that he won't or can't keep my left Ne right sound separate), I keep my rig set up for stereo and only send him my left output #1 signal. Works great. Never phase issues. I monitor myself on stage in my own frfr gear and use my right output #2 for that. This way I hear the other side of the stereo field and can control the volume with the output 2 knob on the front of the axe fx on stage and it won't affect the volume of what I send him out front. Another cool benefit of this is that hou have "left" coming out of either end of the stage And "right" heard from center stage. Stereo imaging on some level on both sides of the stage from audience perspective.

 

[Rex]

Most stereo effects will sound noticeably better with only one channel being heard than electrically summed to mono. Stereo delay is one possible exception, but it's easy enough to convert the desired effect to a mono signal in that case.

Sounds like it's a matter of what you're doing in stereo.

Not every "phase issue" results in complete cancellation of the wet (or dry) signal. Most "phase issues" cause unintended (and unwanted) colorations when stereo signals are summed to mono.

True. Though I'm not sure how that changes the current discussion.

If you truly accomplish that (keeping phasing issues out of the patches you want to run mono), you won't really be taking advantage of the possibilities offered by stereo.

True again. But then you can have dedicated stereo-only patches.

I can see a case for both ways. Time for some more experimentation.

 

[Kilvert]

You can run L/R outs [stereo] to FOH. Chance is the channels will not get panned hard L/R on the console so will essentially get dual-mono going to PA if they are center-panned. If you set up your presets like you would for the studio [stereo], then you do not have to redo everything for live work (and vice versa).

So, are you saying that, if I send L/R outs from the Axe to 2 discreet channels of a mono PA, I shouldn't experience weird phase cancellations i.e. from the chorus or enhancer?

 

[Jay Mitchell]

So, are you saying that, if I send L/R outs from the Axe to 2 discreet channels of a mono PA, I shouldn't experience weird phase cancellations i.e. from the chorus or enhancer?

You will experience "weird cancellations" from either of those effects if they are summed to mono electrically, which is what will happen if you send both left and right signals to a mono PA.

To be certain that stereo effects will not produce audible cancellations when summed to mono, you must eliminate any delay differential between left and right channels that is less than, say, 40 milliseconds. This means you'll have to turn off the enhancer altogether, because that's all it does. You'll need to set the width parameter in the chorus to zero.

 

[Kilvert]

You will experience "weird cancellations" from either of those effects if they are summed to mono electrically, which is what will happen if you send both left and right signals to a mono PA.

To be certain that stereo effects will not produce audible cancellations when summed to mono, you must eliminate any delay differential between left and right channels that is less than, say, 40 milliseconds. This means you'll have to turn off the enhancer altogether, because that's all it does. You'll need to set the width parameter in the chorus to zero.

Thank you Jay!