7thangel
7th Angel of Armageddon
ill o.g.
despite having automatic and plugin delay compensation, logic's is very hinky and flaky, especially with certain plugs and aux channels.
here's a tool to help fix it http://www.expert-sleepers.co.uk/latencyfixer.html
and here's something that should be checked (although it can be tedious)
http://www.logicprohelp.com/viewtopic.php?t=22161&highlight=pdc
SUMMARY: with this procedure you'll be playing back a track from Logic and recording it right back into Logic on another track. This "loopback" recording will likely be out of time (late*) with respect to the original due to latencies inherent in your interface, driver software, etc., things you have no control over. Note that Logic's I/O buffer and process buffer settings will have no influence on this procedure.
This procedure lets you figure out exactly -- to the sample -- how late* your looped-back track is with respect to the original. You'll then enter this number (per the instructions below) into Logic's recording delay setting in the audio prefs. From that point on, your live-recorded tracks will be perfectly in time with when you played them.
The procedure uses phase cancellation of the original and looped-back track to certify that you've found the right recording delay value (you'll see reference to "null point" below, and that's what this is about).
* Note: audio recorded by most audio interfaces ends up being late. But on some systems the recorded audio can actually end up early! And in a few cases it's been reported that a recording delay setting of zero will suffice. The procedure outlined below addresses the more common scenario -- late audio. At some point I will amend this to address early audio. It's the same procedure -- making a loopback recording, but the way to figure out the delay value is just slightly different.
Anyway, here we go!
HOW TO DETERMINE AND SET THE RECORDING DELAY
STEP 0 -- very important!
• Turn software monitoring off
• Turn the metronome off
• Set the recording delay value to zero
• Set PDC off
• Make sure you have no plugins anywhere.
1. Arrange Window, Track 1, assigned to Channel 1 -- import a CD track or use any stereo track of your own, preferably something with sharp transients at the top, like drums or percussion. I'm going to refer to this track as "X". Align it to start at bar 2.
2. Arrange Window, Track 2, assigned to Channel 2 -- set this channel to record from INPUTS 1/2. This is the track you're going to record your looped-back audio on.
3. Make sure the fader levels for both channels (tracks 1 and 2) are set to 0 dB and that both of their outputs are set to OUTPUTS 1/2
4. Use patch cables to connect outputs 1&2 of your audio interface to inputs 1/2 of the interface
5. Start playback at bar 1 and go into record a little before bar 2 (punch on the fly works well for this). This recording -- the "loopback recording" is going to be called "Y". You only need to record about 10 seconds of material max.
6. Take track 2 out of record and insert the Logic > Helper > Gain plug on this channel. Set the L & R channels to be out of phase.
What's going to happen next: you're going to play back both "X" (the original) and "Y" (the loopback recording of "X"). Because of the settings on the gain plug, Y is now out of phase with respect to X. If Logic recorded a perfect copy of X (i.e., the timing of Y is identical to X) then playback at this point would result in silence. Yes, silence! That's because if you playback two exact copies of an audio file and put one of them out of phase, they will cancel each other out.
But chances are that X won't be aligned with Y due to the latency inherent in your audio interface and its driver software. You'll likely hear flamming (slapback echo), or a thin, flanger-like sound. This is a clear indication that your recording delay setting needs to be adjusted.
NOTE: the proper recording delay setting for some systems is indeed ZERO. So if at this point you do actually hear silence, you can conclude the test. If you don't hear silence, continue to the next step...
7. Reduce the level of output 1&2 by 6 dB (this is to prevent clipping at the output in case your tracks are loud)
8. Open "Y" in the sample editor. Zoom ALLLLLLLLLLL the way in to the anchor point as far as you can go. Set the sample editor's "view" to "samples".
9. Click/hold on the anchor point, being careful not to move it. You will now see two numbers in the upper left hand corner of the window. Write down the bottom number.
On most system "Y" will have been recorded late. This means that the top of "Y" contains a little bit of dead air (the latency amount) as compared to the original, "X". We're going to move the anchor point to the right -- one sample at a time -- to get past the dead air and find the null point that causes X and Y to cancel. As follows...
10. Play back your tracks. Move Y's anchor point to the right one sample at a time until you start to hear the sound thin out. Start/stop Logic as needed. As you move the anchor more and more to the right the sound will thin out more and more. As you get closer to the null point a steady, flanger-like "pitch" will start to form in the sound. If the pitch gets increasingly higher you know you're moving in the right direction.
You will reach a point where the sound is extremely thin and almost silent, and then, moving one more sample to the right, it will cancel completely. When this happens, click and hold on the anchor and write down the bottom number.
11. Subtract the first number from the second number. Then put a "-" in front of it. THAT's your recording delay value; set it in your audio prefs.
To confirm that this is the correct number
12. Delete "Y". Make a new loopback recording on track 2. This is going to be called "Z".
13. If the number you calculated is correct, and the Gain plug is still active on track 2 (putting "Z" out of phase with the original "X"), when you play back both tracks now you will hear silence. To confirm, bypass the plug and you should hear your original track 2x as loud.
If upon playing back X and Z the sound is still not perfectly canceling, adjust your recording delay +1 or -1 from the value you calculated and repeat steps 12 and 13 again.)
this most def helped me when i was recording using logic pro, and especially when turning hardware synths from midi to audio.
here's a tool to help fix it http://www.expert-sleepers.co.uk/latencyfixer.html
and here's something that should be checked (although it can be tedious)
http://www.logicprohelp.com/viewtopic.php?t=22161&highlight=pdc
SUMMARY: with this procedure you'll be playing back a track from Logic and recording it right back into Logic on another track. This "loopback" recording will likely be out of time (late*) with respect to the original due to latencies inherent in your interface, driver software, etc., things you have no control over. Note that Logic's I/O buffer and process buffer settings will have no influence on this procedure.
This procedure lets you figure out exactly -- to the sample -- how late* your looped-back track is with respect to the original. You'll then enter this number (per the instructions below) into Logic's recording delay setting in the audio prefs. From that point on, your live-recorded tracks will be perfectly in time with when you played them.
The procedure uses phase cancellation of the original and looped-back track to certify that you've found the right recording delay value (you'll see reference to "null point" below, and that's what this is about).
* Note: audio recorded by most audio interfaces ends up being late. But on some systems the recorded audio can actually end up early! And in a few cases it's been reported that a recording delay setting of zero will suffice. The procedure outlined below addresses the more common scenario -- late audio. At some point I will amend this to address early audio. It's the same procedure -- making a loopback recording, but the way to figure out the delay value is just slightly different.
Anyway, here we go!
HOW TO DETERMINE AND SET THE RECORDING DELAY
STEP 0 -- very important!
• Turn software monitoring off
• Turn the metronome off
• Set the recording delay value to zero
• Set PDC off
• Make sure you have no plugins anywhere.
1. Arrange Window, Track 1, assigned to Channel 1 -- import a CD track or use any stereo track of your own, preferably something with sharp transients at the top, like drums or percussion. I'm going to refer to this track as "X". Align it to start at bar 2.
2. Arrange Window, Track 2, assigned to Channel 2 -- set this channel to record from INPUTS 1/2. This is the track you're going to record your looped-back audio on.
3. Make sure the fader levels for both channels (tracks 1 and 2) are set to 0 dB and that both of their outputs are set to OUTPUTS 1/2
4. Use patch cables to connect outputs 1&2 of your audio interface to inputs 1/2 of the interface
5. Start playback at bar 1 and go into record a little before bar 2 (punch on the fly works well for this). This recording -- the "loopback recording" is going to be called "Y". You only need to record about 10 seconds of material max.
6. Take track 2 out of record and insert the Logic > Helper > Gain plug on this channel. Set the L & R channels to be out of phase.
What's going to happen next: you're going to play back both "X" (the original) and "Y" (the loopback recording of "X"). Because of the settings on the gain plug, Y is now out of phase with respect to X. If Logic recorded a perfect copy of X (i.e., the timing of Y is identical to X) then playback at this point would result in silence. Yes, silence! That's because if you playback two exact copies of an audio file and put one of them out of phase, they will cancel each other out.
But chances are that X won't be aligned with Y due to the latency inherent in your audio interface and its driver software. You'll likely hear flamming (slapback echo), or a thin, flanger-like sound. This is a clear indication that your recording delay setting needs to be adjusted.
NOTE: the proper recording delay setting for some systems is indeed ZERO. So if at this point you do actually hear silence, you can conclude the test. If you don't hear silence, continue to the next step...
7. Reduce the level of output 1&2 by 6 dB (this is to prevent clipping at the output in case your tracks are loud)
8. Open "Y" in the sample editor. Zoom ALLLLLLLLLLL the way in to the anchor point as far as you can go. Set the sample editor's "view" to "samples".
9. Click/hold on the anchor point, being careful not to move it. You will now see two numbers in the upper left hand corner of the window. Write down the bottom number.
On most system "Y" will have been recorded late. This means that the top of "Y" contains a little bit of dead air (the latency amount) as compared to the original, "X". We're going to move the anchor point to the right -- one sample at a time -- to get past the dead air and find the null point that causes X and Y to cancel. As follows...
10. Play back your tracks. Move Y's anchor point to the right one sample at a time until you start to hear the sound thin out. Start/stop Logic as needed. As you move the anchor more and more to the right the sound will thin out more and more. As you get closer to the null point a steady, flanger-like "pitch" will start to form in the sound. If the pitch gets increasingly higher you know you're moving in the right direction.
You will reach a point where the sound is extremely thin and almost silent, and then, moving one more sample to the right, it will cancel completely. When this happens, click and hold on the anchor and write down the bottom number.
11. Subtract the first number from the second number. Then put a "-" in front of it. THAT's your recording delay value; set it in your audio prefs.
To confirm that this is the correct number
12. Delete "Y". Make a new loopback recording on track 2. This is going to be called "Z".
13. If the number you calculated is correct, and the Gain plug is still active on track 2 (putting "Z" out of phase with the original "X"), when you play back both tracks now you will hear silence. To confirm, bypass the plug and you should hear your original track 2x as loud.
If upon playing back X and Z the sound is still not perfectly canceling, adjust your recording delay +1 or -1 from the value you calculated and repeat steps 12 and 13 again.)
this most def helped me when i was recording using logic pro, and especially when turning hardware synths from midi to audio.
