Vocal tracking - double flange/phase issues

I was trying to track vocals (which I've done plenty of times before) and ran into a strange effect through my headphones while monitoring.

It sounds like a faint "doubling/echo" with a flange type sound. When I play back the file it sounds fine.

I haven't changed anything in Logic. In addition, I checked how it would sound in Garageband. Same issue. Tried a fresh restart and no difference.

With QuickTime 7 and X it doesn't happen.

Anyone ever had this happen?

Its as if double monitoring is on somewhere. Last I checked my Logic settings, everything looked fine and untouched.

edit:

I ran standalone through the ULN2, no problem.

So this is only happening through Logic and Garageband.

Latency is the same its always been as well.

This is confusing

Sounds like you're monitoring through the ULN2 AND through Logic via Software Monitoring.

Use one or the other, but not both.

Thats what I thought originally. But I didn't change any settings in either. I always monitor through Logic due to the software monitoring option. When I monitored through ULN only everything was fine. Yet for some odd reason going through Logic ONLY seems to create this strange effect.

Besides the audio tab (the one here,

http://help.apple.com/logicpro/mac/9.1.6/en/logicpro/usermanual/Art/S15/S1522_LE_REC_PrefSoftwMonit.png )

is there any other place/tab/ or part of logic that one should look into to see if any settings are possibly messed up?

Even though the resulting track recording sounds fine in the end, during the tracking process, with the echoing going on its quite annoying as one would imagine.

Update -

This is a Logic 9 bug. Comes and goes depending on existing projects being opened. I've tested it out according to quite a few other postings online and complaints.

Upon opening new projects half the time it works fine. (If not all the time) But if I want to open an existing project and try to track vocals there is a echo.

Others have documented this, but they themselves have yet to find a solution.

Is there some sort of preference file or something that I can delete in one of the Logic folders to bring this back into working order?

Its as if some sort of file is corrupt somewhere. This is horribly annoying.

If you have what I sometimes have (which is a latency through Software Monitoring of 0.2 (already a lot, "echo") to sometimes 1.0 seconds in a project with a buffer setting of 128 or 256), then yes, this is a known semi-bug. I say semi, because it only happens if I have used any other app (usually iTunes) that uses the audio hardware, while Logic is open.

The solution is simple: in Logic, go to the Audio Preferences, untick and retick the Enabled checkbox, and dismiss the dialog box. This will restart coreaudio, without having to restart Logic.

The flanging is normal, a latency of 128 samples is still almost 3 ms (at 44,100 Hz), enough to cause a "flanging" between what you hear in your phones and what you hear through your bones.

Hmmmmmm, that fixed it (for a short time), but interestingly enough....I didn't have anything else open, just Logic. (I'm running at 128 as well)

In addition, something I noticed,

If I uncheck it (Enabled checkbox) and do as you say. It fixes it. BUT, as soon as I play the project for a second/ or unclick "record enable" or "input monitoring" and then re-enable record/monitoring, its back there again. For some odd reason it gets activated by playing the project or unclicking and reclicking the monitor button/record enable. And funny enough its happening on a 13+ track project.

I recall this happening to me in the past, but I had no idea what was going on, so I restarted from scratch and it may or may not of fixed it for that time being.

I wonder, has Apple ever addressed this issue in a update? My guess is not.

Kinda annoying to keep having to uncheck and recheck the Enabled box when it creeps out. Also, when using a buffer of 32, it was present, so its definitely one weirdo of a bug.

Luckily it doesn't transfer into the final recorded file.

Thanks for clearing that up.

Sure thing.

I've removed all plug ins as a test too (in the project) and it didn't help.

I'm wondering perhaps its a RAM issue, then again I think its just a bug, since it comes and goes. (and only happens in Logic)

mixer

Thats what I thought originally. But I didn't change any settings in either. I always monitor through Logic due to the software monitoring option. When I monitored through ULN only everything was fine. Yet for some odd reason going through Logic ONLY seems to create this strange effect.

Of course you will hear this if you have software monitoring enabled. The ULN is giving you the direct signal. Logic is giving you a delayed signal. When you say "going through Logic ONLY seems to create this strange effect" you are not actually going through Logic only. Enabling Software monitoring doesn't mean that you are switching from listening to input signals via the ULN to listening via Logic, it means that you are now listening to two sources of the audio at once. Disable SM and you are left with only one signal, the ULN's.

Even if the ULN will allow you to turn off the monitoring level of the input signal, (thus leaving only Logic's delayed signal), if you are recording your own vocals, you'll hear the live sound right in the air mixed in with Logic's delayed signal. It's not a question of whether or not Logic will delay the signal when Software Monitoring is on, it's how much and how perceivable that delay is.

Even though the resulting track recording sounds fine in the end,

Yes, it would sound fine as soon as there is no longer an input signal doubling what logic is putting out.

during the tracking process, with the echoing going on its quite annoying as one would imagine.

If software monitoring is enabled and you have any serious kind of buffer set up, then yes, you are inevitably going to be hearing two signals at once. The solution when tracking vocals is to turn off software monitoring. The only time I use software monitoring is if I want to play an effect while I'm tracking, like a guitar amp plug for instance.

The fact that you've never had this problem before is mostly due to luck, small buffer settings and the absence of CPU hungry plugs like reverbs, which will cause plugin delay compensation to kick in. Generally, when tracking, you'll want to turn PDC off here:

Preferences / Audio / General Tab

One of the nice things about only using direct monitoring when tracking (no software monitoring enabled) is that it doesn't matter how large the buffer is. The signal from Logic will be delayed, but you won't know or hear it as being delayed and your incoming vocals will land exactly where they are supposed to. In fact, I'm not even sure that in this instance PCD will make any difference, except inasmuch as it keeps the tracks with CPU hungry plugs on them time aligned within Logic.

Of course you will hear this if you have software monitoring enabled. The ULN is giving you the direct signal. Logic is giving you a delayed signal. When you say "going through Logic ONLY seems to create this strange effect" you are not actually going through Logic only. Enabling Software monitoring doesn't mean that you are switching from listening to input signals via the ULN to listening via Logic, it means that you are now listening to two sources of the audio at once. Disable SM and you are left with only one signal, the ULN's.

Even if the ULN will allow you to turn off the monitoring level of the input signal, (thus leaving only Logic's delayed signal), if you are recording your own vocals, you'll hear the live sound right in the air mixed in with Logic's delayed signal. It's not a question of whether or not Logic will delay the signal when Software Monitoring is on, it's how much and how perceivable that delay is.

I'm not sure if this'll make sense, but the ULN is always "off" in terms of "standalone" operation. For example. If I start up the computer and stick in a guitar cable DI, straight into either channel, crank up the gain, I don't hear anything. I see the input levels but If I want to hear that signal output (of me playing) I have to open some type of audio software (whether it be Quicktime, Logic, Garageband, etc) and activate input monitoring or record enable.

Now, if I want to track using direct monitoring; using my unit in standalone mode, I then have to open up software that came with the ULN and open it, activating the ULN into standalone operation. Now that its activated I don't have to have software monitoring engaged or input monitoring turned on. It can simply work as a preamp at that point (with or without a computer) The problem with this ofcourse is the inability to use amp simulations (ie. Logic) without muting the specific channel within the software and then going back to logic and activating software monitoring.

I understand how it works, I just don't get why it would double the signal (in certain circumstance) since I never run my unit in standalone.

Funny enough, it comes and goes within the project and is only evident on specific projects. And it doesn't help whether I go down from 128 to 32 buffer. (usually i stay at 128)

I'm thinking its something to do with plugins and CPU usage or something.

One of the nice things about only using direct monitoring when tracking (no software monitoring enabled) is that it doesn't matter how large the buffer is. The signal from Logic will be delayed, but you won't know or hear it as being delayed and your incoming vocals will land exactly where they are supposed to. In fact, I'm not even sure that in this instance PCD will make any difference, except inasmuch as it keeps the tracks with CPU hungry plugs on them time aligned within Logic.

Thats good to know. Now, what If I'd like to hear some reverb on my vocal track using direct monitoring when tracking??? (no software monitoring enabled, just my ULN) I've tried to figure this out, but I'm missing something.

Also, buffer sizes wouldn't matter here as you say? I have the luxury of tracking at 64 or even 32 if I wanted too. But you say this doesn't make a difference when using direct monitoring, besides the obvious fact i'll be hearing the the signal of whatever I'm tracking over from Logic coming through my headphones.

Thanks for the input!

Funny enough, it comes and goes within the project and is only evident on specific projects. And it doesn't help whether I go down from 128 to 32 buffer. (usually i stay at 128)

 

I'm thinking its something to do with plugins and CPU usage or something.

Well, could be but it's worth noting that the digital console that comes with the ULN is a complex beast and signal routing can get confusing. I still think that if you are hearing two signals it's because you're monitoring from both the ULN and from Logic simultaneously. Sometimes you might not hear it because you've got the buffer set so low that the doubling is not very noticeable but in that situation, it would be there non-the-less. But when tracking your own vocals you'd tend to notice flanging even at low buffer settings because you're hearing your voice immediately, inside your own head and as Erik pointed out, even a buffer of 32 will create a flanging effect.

One of the nice things about only using direct monitoring, etc etc....

Thats good to know. Now, what If I'd like to hear some reverb on my vocal track using direct monitoring when tracking??? (no software monitoring enabled, just my ULN) I've tried to figure this out, but I'm missing something.

You can't do it that way; you need software monitoring on so that you can, um, monitor the software. Makes sense?

What I do instead is to use a hardware reverb that comes in on separate inputs on my I/O box.

Also, buffer sizes wouldn't matter here as you say? I have the luxury of tracking at 64 or even 32 if I wanted too. But you say this doesn't make a difference when using direct monitoring, besides the obvious fact i'll be hearing the the signal of whatever I'm tracking over from Logic coming through my headphones.

What I'm saying is that when you use ONLY direct monitoring, then the buffer size doesn't matter.

At any rate, I hope all this has shed some light on the ins and outs of direct and software monitored audio. I've given you the sorcerer's explanation but for the short story, please refer to this!

Now, what If I'd like to hear some reverb on my vocal track using direct monitoring when tracking??? (no software monitoring enabled, just my ULN) I've tried to figure this out, but I'm missing something.

Hardware reverb

OR

Direct monitor through the ULN

Enable Software Monitoring in Logic

Pull the fader on the record enabled channel strip all the way down (silence)

Use a Pre-Fader bus send to your Aux with reverb plug inserted

Thanks for the tips guys. Good food for thought.

Technically speaking, I "could" track vocals even with the crop up of the "doubling" sound. But in order to get an authentic true vocal sound I'm better off sticking to direct monitoring from now on for vocals and micing in general. The only "real" use for software monitoring is when I'm using the amp sim, or a bunch of plug ins (ie. sculpting weird sounds and what not) and that's not too frequent. Plus with the ULN software I'm getting almost no latency. Big plus.

Redlogic, thanks for that. I'm gonna try that out. I was waiting for someone to throw in "hardware" at some point in time and I was right!

Edit

 

Hardware reverb

 

OR

 

Direct monitor through the ULN

Enable Software Monitoring in Logic

Pull the fader on the record enabled channel strip all the way down (silence)

Use a Pre-Fader bus send to your Aux with reverb plug inserted

Tried it like you suggested, works like a gem.

 

What I'm saying is that when you use ONLY direct monitoring, then the buffer size doesn't matter.

 

At any rate, I hope all this has shed some light on the ins and outs of direct and software monitored audio.

I tried it both at 64 and at 1024. No difference as you stated. Even zoomed in on the audio wave to check the starting point. Usually there is a significant differences between those buffers, but with direct monitoring, nothing. This is good stuff. This really makes you think about using software monitoring in the first place, especially when everything is mic'd up .

Thanks again guys.