LOGIC PRO 8 - Aux Latency I/O Fixes

[starseed]

Urgh...

New to Logic, since last summer. In Cubase, I would sometimes record tracks to tape, and have them automatically re-align themselves with the original, after a quick set-up, which was saved as a hardware effect setting file. This required nothing but intuition and technology included with the program.

Looking to do the same thing in Logic, I ran into a few obstacles. I read this thread, checked with the creator of Latency Bundle (Artificial Audio) and bought it. I open the manual file, where it is described how to determine the latency of one's converters (and any outboard) and compensate for it. As an example, this uses two instrument-type channels.

I can duplicate that fairly easily, and since I am using a tape machine in my example, I would get a variation, in between -3 and +5 samples, showing a little motor instability (damned fine machine though, a Studer C37 from the 60's). However, That is where the fun ends, until I get my head around it...when applying the "latency compensator" plugin alone on a channel (and this may be where my newbieness in Logic is at fault) I get a constant gap of grossly misaligned audio files...even with radically different settings, bypassing everything...yada yada, but never even close to right.

Being that I have done this before using better tools, I am a little disappointed, and more than a little frustrated.

I am definitely doing something wrong, and a few of you seem to have gottten it right, using a bus as output, with an I/O plugin followed by a latency correcting plugin, or so I gather.

I have tried that too, and that's when the newbieness rears its' head again, leading to all sorts of results, but nothing I want.

Man, was it easy in Steinberg-land. Someone, in a language I can understand, set this right. It took me ages to understand half of what is being said in this thread due to Logic-clature issues...and I still feel clueless.

Logic 8 w. Apogee R. 800, out, via tape machine and back in, in sync...kazaam stike

I believe it can be done...I have the necessary tools...what am I doing wrong?

Thanks,

Jeremy Barnes

[emfrank72]

Originally Posted by dkatz42

You need to solo-safe the output. Control-click the solo button.

I tried to control click the solo button which puts a slash across it but I still can't hear anything.

[starseed]

Still not working

[M-Goldie]

Originally Posted by starseed

Still not working

hello. i can't quite get my head round what you are trying to achieve but i thought i would run you through what i have been doing and hope it helps.

i have just spent nearly 2 days (!) trying to hook up an Eventide DSP700 to logic 8.02 so i can use it as an external hardware FX send. thanks to this thread (which i found at the start of day 2) i think i have solved it. i've not road tested it yet but i've done numerous small tests and now it is all working.

most of this is described in previous posts, but here is my working setup. make sure 'plug in delay is set to 'All' and also download and install 'expert sleepers' free 'latency fixer' AU plugin:

1. in the mixer set up an aux channel (Aux 1) to be the 'fx send'. set its input as a bus channel, for example i'll use bus 1.

2. in the 'environment' window, view the mixer and create a bus channel strip. in the environment inspector window (to the left) make sure this is the correct bus channel (bus 1).

3. on this bus channel insert the i/o plug and below it the latency fixer (set this to zero samples). set the i/o plug to the correct ins and outs for your external hardware.

4. now you need to find the latency. i do this by firstly dropping an apple loop onto an audio track - i use one of the sharp 'analog drum beats'. pan this track hard left and use a send to bus 1 at 0db.

5. set your hardware FX unit wet/dry knob to 'dry'.

6. set the Aux 1 channel in the mixer to pan hard right. you should now find that the signal from track 1 is returning from your fx unit with a very small delay. so what you've got is the pre-send signal in the left, and the returned signal on the right.

7. bounce a short file. this obviously needs to be done in realtime.

8. open the file in whatever sample edit program you like, i use Peak. it should be pretty straightforward to zoom in close enough to be able to see that the right channel slightly lags behind the left. measure this in samples (mine was 74 samples for an SPDIF connection).

9. go back to logic, in the latency fixer on the bus 1 channel strip put in this sample amount.

10. re-do steps 7 and 8, you should find it is sample perfect between left and right channels.

11. put your FX unit back to 100% wet, pan the channels back to the middle and off you go!


one problem is you can't solo the Aux channel. there is a workaround by soloing various tracks in the environment but its not really worth the bother.

if you want to bounce the wet FX send to put into the project as a file on a track, then create an audio track with 'bus 1' as its input. i think you need to mute it while you record.

so far this is working for me. i am hoping that latency values don't change when instruments and other stuff are added, but i've done some tests and so far it seems fine.

cheers
mg


p.s. this is obviously a big problem in Logic and i hope the apple people are reading...

[thermos]

Originally Posted by malcolm goldie

p.s. this is obviously a big problem in Logic and i hope the apple people are reading...

Arrrgh, I've been using the same techniques and it works on some sessions, and not on others. HUGE BUG. IMO it cannot be a fully pro daw without this feature.

[Delta Heavy]

Originally Posted by thermos

HUGE BUG. IMO it cannot be a fully pro daw without this feature.

agreed, it's ridiculous

[audiomichael]

Originally Posted by thermos

Arrrgh, I've been using the same techniques and it works on some sessions, and not on others. HUGE BUG. IMO it cannot be a fully pro daw without this feature.

I'd be curious to see what's going on in your session when it doesn't work. I've been using this flawlessly for 5 months.

- not that we should have to do this at all, Apple please fix this ! -

[thermos]

Originally Posted by audiomichael

I'd be curious to see what's going on in your session when it doesn't work. I've been using this flawlessly for 5 months.

- not that we should have to do this at all, Apple please fix this ! -

Well, I found a random fix. I've been using the create bus in the environment, and for some reason when I send from an aux (say to add hardware verb to drum rooms for instance), the Lexicon will show that its receiving gain, and the io box reads that its sending and receiving info from the correct ios. But the bus channel in Logic won't sound. However, if I just send to the same bus from an audio track (even if the send is at 0) it will immediately start registering the other send. Weird and buggy. But it works so whatever.

[audiomichael]

Originally Posted by thermos

Well, I found a random fix...

YOWZA! That is weird and buggy!

[Osumosan]

Once you have figured out the latency of your DA/AD loop, you cannot insert compensation on an AUX that uses the I/O plug. You must go to the environment and create an object for the BUS that the AUX channel is using. Menu: New/Channel Strip/Bus. Then insert the I/O and latency fixing plug on the bus object and it will work properly. Of course if you want to keep track of the plugs in your mixer, you need to make a track in the arrange page for that BUS. Then just remember that you have both the AUX and the BUS in your mixer. It's a bit awkward, but at least the compensation will work for you.

Originally Posted by SoundEng1

Can you guys show me how to do this?

Thanks!

[Melissa]

Originally Posted by emfrank72

I feel your pain. I never had issues with Logic until I started getting some nice outboard gear. I can insert compressors on individual channels using latency fixer (can't remember the exact delay compensation but 86 does kind of ring a bell). However, I was trying to use my API compressor for parallel drum compression and no matter what I did, I couldn't seem to dial in the right amount of delay using latency fixer and the drums were incredibly phasy. I basically gave up and put the API on permanent 2-buss duty for now. I have thought about switching to Cubase/Nuendo but it seems no matter what platform I use, I find things I don't like about it so I might as well stick with Logic.

I have ran into a problem when using the IO plugin. It seems that if I solo a channel with the IO plugin that I get no audio. The only way to solo a channel is to mute the rest which is kind of a pain. I hope there is an easy solution to this one at least.

When doing parallel on drums (with outboard) you have to be within a sample ...and it seems that latency fixers aren't that accurate...IMO you have to earball, and you can accurately

[Osumosan]

Originally Posted by Melissa

When doing parallel on drums (with outboard) you have to be within a sample ...and it seems that latency fixers aren't that accurate...IMO you have to earball, and you can accurately

I use the artificial audio plug in for measuring the latency of my system and it works to the sample. You can also hear by ear by summing a phase reversed signal where the compensation is perfect. And you will hear a difference from sample to sample.

It works for me. It'll work for you.

[Melissa]

Originally Posted by Osumosan

I use the artificial audio plug in for measuring the latency of my system and it works to the sample. You can also hear by ear by summing a phase reversed signal where the compensation is perfect. And you will hear a difference from sample to sample.

It works for me. It'll work for you.

Sounds good..which artificial audio plug do you speak of and does it work with Logic's delay compensation?

summing a phase reversed signal to calculate....very cool

[Osumosan]

This is the plug I use:

Artifical Audio - Latency Bundle

If tiny adjustments are needed, and they usually aren't, I also use Airwindows' sample delay to do the phase reverse because it has a sample by sample delay that can be adjusted in real time. Most plugs you'll have to start and stop playback in order for a change in value to be registered.

[fossaree]

Anybody know if this have been fixed in LOGIC 9 ?

Also , how about plugin delay compensation , is it full now on logic 9 ?

[Osumosan]

L9 does not fix the I/O on the Aux object bug, nor does it compensate for I/O latency in any way. You still have to use the detectors and compensators. Other than that, I have no issues with Logic's delay compensation with any in the box plug-ins.

[fossaree]

Originally Posted by Osumosan

L9 does not fix the I/O on the Aux object bug, nor does it compensate for I/O latency in any way. You still have to use the detectors and compensators. Other than that, I have no issues with Logic's delay compensation with any in the box plug-ins.

Hey thanks .

I'm already using L9 but didn't really checked about PDC . Once you're telling me that I must say I'm more calm.

Anyhow it's a pitty they didn't cover i/o-aux bug . So sad ...

[thermos]

Originally Posted by fossaree

Hey thanks .

I'm already using L9 but didn't really checked about PDC . Once you're telling me that I must say I'm more calm.

Anyhow it's a pitty they didn't cover i/o-aux bug . So sad ...

Yeah, but for the die hards who have to have it work, the methods described in this thread work like a charm. I've been doing it for months now, very solid and reliable (quirks and all).

[Osumosan]

Originally Posted by thermos

Yeah, but for the die hards who have to have it work, the methods described in this thread work like a charm. I've been doing it for months now, very solid and reliable (quirks and all).

Agreed. And once you know the latency of your system, you can have presets for your compensators and for me it hardly ever changes. It does, sometimes, so you have to keep your ears open!

[fossaree]

as a matter of fact , altought i'm a logic lover and use it for my living (and not even thinking about changing!) ... I must say it's an absurd they didn't cover this in L9 ... I mean it's a Pro app .. Absurd !

[Osumosan]

So just for my edification, which DAWs do compensate for hardware insertion latency by themselves?

[fossaree]

I can't say about other daws ...but If I 'm not wrong , I think cubase does that ...
not quite sure

[fossaree]

BTW, actually Logic does have outboard latency compensation . Its only problem is when inserted on AUX track (bus) . But when its inserted on a channel as an insert effect , it works properly .

[Osumosan]

Yeah, but not by itself. You have to do it manually or with third party detectors and if anything in your system changes (i.e. sample rate), you need to recalculate. I also found that once in a blue moon, things go a little faster or a little slower. Dunno why, but I use a lighpipe interface with three different converters, each one has it's own latency.

[fossaree]

ah i see what you mean ... In that fashion , I think pro tools HD .

[staudio]

Nuendo has a "ping" feature which measures the latency of an outboard process and then automatically compensates, it works most of the time. Logic should incorporate this feature.

Another thing which I would like to see is a new standard that allows ADDA converters and software drivers to report their latency in real time so as to enable dynamic latency compensation to eradicate issues of latency drift due to temperature changes or other causes, or maybe converters should round up their latency to whole samples so as to allow a fixed compensation scheme that does not have to deal with sub-sample latency problems?

[fossaree]

that would be nice ...

[Osumosan]

Anyone feel like bringing this up at AES? Do you think the standards board (AESSC) would be interested?

[staudio]

Originally Posted by Osumosan

Anyone feel like bringing this up at AES? Do you think the standards board (AESSC) would be interested?

I can look in to it, though I confess I would not know where to begin in preparing a proposal for the technical aspects of the idea. I am better with the concepts, rather than the implementation.

[Osumosan]

I'm willing to wager they have their own ways of taking care of this. Just hearing from us might help them think of this as a priority. I know it is for me