Latency Problems - Need Tips

[Bush Man]

Hello, I'm having major problems with Latency. I just started researching solutions today. I have 002R. I run a 2.8 MHz machine with 1GB RAM. The machine has an 800 MHz FSB.

It is impossible for me to record a live musician in sync with prerecorded tracks. The musicians hear the notes that they play delayed in the monitoring of the track. When I play back the recording, the newly recorded part is behind the beat.

I tried to have a drummer and a bass player record with a Pro Tools generated click. It was a disaster. There is even Latency when I try to sync with my MPC.

I’ve reviewed many Latency postings.

Please help if you can. I don’t have time to experiment.

Does the same problem happen in MAC based systems?

If I get an HD or TDM system, does this problem go away?

I have the monitor outs of my 002R plugged into 2 channels on my analog mixer which is plugged into my amp.

I plug MICs and instruments directly into the 002R.

The latency can be heard through my mixer and through the 002R headphone output.

If I turn all compression and reverb off on all of my tracks that are being played back while recording, will this improve the Latency problem?

I read something about muting the track that is record enabled. Does that work?

I know there is a solution, because there are so many successful Pro Tools recordings. The system is no good to me if I can’t track parts separately. I’ve recorded live bands with no problem, but I must be able to record new tracks later. I currently will have to nudge tracks X ms to get parts on beat. This is a waste of time.

THANKS!!

[Zetajazz44]

I may be way off here, but I just 'check' Low Latency monitoring from the menus at the top of the PT application... That seems to do the trick for me... Just a tip...

[JMS40]

Yes, Low Latency setting is an option, but you'll loose the use of your plugins.

What is your Buffer Size set to, Bush Man?
I find the latency almost unnoticeable with the 128 buffer setting.

[tele_player]

Bush Man (gee, I hope that means you live in the bush)...

Latency with ProTools LE is the same on Mac and PC.

Latency is controlled by the setting for H/W Buffer size - what were you using? Try 64 or 128. Most people don't even notice latency at those settings. You can also try the Low Latency Monitoring mode, but that disables plugins on the record-enabled track during recording.

[Bush Man]

My H/W Buffer size was set to 1024. The lowest setting that worked was 256.

When I had my file open, I could not select anything lower than 256 without getting an error.

If I close PT, and open it, I can select 64 or 128 if I do not open a project.

If I open a project and have the H/W Buffer set to 64 or 128, the project will not play. I get an error. The project will only play if the H/W Buffer is set at least 256 Samples.

The error that I got in both scenarios is as follows:

“The Operating System held off interrupts for too long. If this occurs frequently, try increasing the ‘H/W Buffer Size’ in the Playback Engine Panel. (-6089)”

The errors occurred with Low Latency Monitoring enabled also and disabled.

I only had time to change the setting to 256. I will see if I still get the latency problem tonight.

Thanks,
Bush Man

[sawtooth]

it's a tough solution. the fact is, that you can't have it all with host based systems because of how the processing works. This is true for any host based systems, not just Pro Tools. There are, however a couple of remedys that are work-arounds. 1. the HW Buffer size must be set as low as possible for recording. this is why you are able to change this because this allows you switch between running more plugs at a higher HWBuffer or rec at a lower buffer. Now, you'll notice that you will have problems actually running the system with a lot of plugs at this lower buffer rate so, the second thing that you can do is bypass as many plugs as possible. Low Latency monotoring does this for you, but there is anoter way by individually de-activating each plug-in by holding dowon Cntrl+Start and clicking on the plug-in in the mix window. (not Cntrl+click, this simply bypasses the plug, Cntrl+start+click actually takes off the processing) Do both of these things, Low HWBuffer and De-activate the plugs that you don't need while recording THEN, mute the track that you are recording to. you should have some success if you do all of these things tog. hope this helps...

Sawtooth.

[Bush Man]

Thanks a lot!

I will try this. Is Cntrl+Start a MAC key combination? I will find out what the PC shortcut is.

Thanks,
Bush Man

[Chris Cavell]

bushman,

What type of mixer do you have? There may be a way of connecting your system for zero latency monitoring depending upon your mixer.

Other than that, I need more system info...what little you gave should work with a buffer setting all the way down to 64 no problem. Hard drives? Anything running in the background?

[sawtooth]

Thanks a lot!

I will try this. Is Cntrl+Start a MAC key combination? I will find out what the PC shortcut is.

Thanks,
Bush Man



no, its a PC scut. start is right next to the Control key on the bottom left.

[Bush Man]

Yeah, DUH on me.

[Bush Man]

bushman,

What type of mixer do you have? There may be a way of connecting your system for zero latency monitoring depending upon your mixer.

Other than that, I need more system info...what little you gave should work with a buffer setting all the way down to 64 no problem. Hard drives? Anything running in the background?



I have a BEHRINGER Eurodesk MX3282A - 32-Channel 8-Bus Recording/Live-Mixer. I just use it to monitor outputs of the 002R and my MIDI gear. When I record, I plug the gear directly into the 002R.

I built the machine. The motherboard is an ASUS P4P800-E Deluxe. See for exact specs: http://usa.asus.com/products/mb/socket478/p4p800-e_d/overview.htm . The firewire, video, S/PDIF, second video output, USB is all integrated into the motherboard.

I’ve installed an Intel 2.8 GHz Processor. Hyper Threading is turned off. 1GB RAM.

My boot disk is 80 GB. My Production disk is 200 GB. Both drives are internal IDE at 7200. I have a lot of video files on my production disk. Can a fragmented hard drive cause latency? There is about 100 GB free.

I have a NEC DVD +/- R DVD Burner. It's the 1300a. I also have a combo DVD Player/CD-R/W burner drive in the same computer.

This computer is not on my LAN. I have no Internet access, no firewall, no virus software. There is only sequencing software, Avid DV Free, and other Video/Music/DVD Authoring programs.

THANKS

Bush Man

[Room24Prod]

What kind of pre-amps are you using? I've been wanting to experiment with my Behringer mixer. What I'm think will work is if you have multiple outputs on your pre-amp then you can have a set of outputs, in my case my lite pipe out of my Presonus Digimax going straight into my 002R, and then have another set of outputs going into the mixer for monitoring in real time, without latency. So basically I would have the mic going into the pre-amp, and the signal is split into 2 different directions. My lite pipe output on the Presonus goes into the 002R to record, and then my XLR or 1/4 inch output goes to my Behringer and the singer can listen to the mixer via headphones. Then I can create a separate bus for each channel for a "headphone mix". Let's say Analog 7-8 outputs. Run those 2 into the mixer so the artist can hear all the music, minus the record enabled track, which would be affected by the latency. So in a nutshell, they're listening to themselves direct and not being routed through the 002R, thus eliminating the latency.

I think that would work. lol

[tele_player]

Can a fragmented hard drive cause latency?



Not really. The latency is controlled by the H/W buffer size, plus a small amount of latency in the converters. An excessively fragmented hard drive would typically cause playback to stop with an error.

With a calculator, you can estimate the latency pretty well: buffer size times 2, divided by sample rate. This will give you the latency in seconds, but since it's a pretty small number, it's more appropriately expressed in milliseconds.

You should take a step back and learn how to minimize the latency, how to optimize your plugin use, how to use Low Latency Monitoring, and how to use an external mixer for zero latency. First start a new, very simple session, and experiment until you understand. Afterwards, you should know how to handle the session you've already got.

[Bush Man]

Everyone has been a big help. Thanks for all of the tips. I will try different setups through the weekend. I'll report my findings. I understand all of the tips and why I have problems.

Bush Man

[halfguard]

i dont even notice the latemcy on my system. i have a sweetater pc with a 002rack. will there always be latency, no matter what? if so i guess this means that everyone has to nudge there tracks, atleast a little? i was going to get a mixer, but was talked out of it because all i could afford was a mackie and it would ruin my sound quality..

[Bush Man]

First of all, selecting "Low Latency Monitoring" helped. I lowered my buffer to 256. I don't know why I can't select 64 or 128 without getting an error. Disabling plugins that I did not need helped if I did not want to use Low Latency Monitoring. I was able to record with no apparent latency.

I don't have a preamp for my MICs. I will buy a new condenser mic with a preamp soon. In the mean time, I’m going to try plugging MICs and instruments into my mixer first. I will then use a send to send the signals to my 002R. My mixer is fairly quiet. I am not worried about too much noise. I’ll report what happens. The preamp solution suggested above will probably be better.

Bottom line on Latency…
I think most users do what I did. They jump into LE without reading the book. Key concepts must be understood, such as using the BUS features, Buffer size and grouping tracks. If you try to put compression and reverb on every track, you will have latency for sure. You can record without latency if you set up and mix your session correctly.

It would be nice if DIGI would provide a hardcopy of the reference guide. I don’t like scrolling through a PDF file. It’s too many pages to print.

Bush Man

[tele_player]

i dont even notice the latemcy on my system. i have a sweetater pc with a 002rack. will there always be latency, no matter what? if so i guess this means that everyone has to nudge there tracks, atleast a little? i was going to get a mixer, but was talked out of it because all i could afford was a mackie and it would ruin my sound quality..



halfguard -
No, you don't need to nudge your tracks to correct for latency. ProTools takes care of that (at least in recent versions). The latency issue primarily affects what we hear in the monitors/headphones while overdubbing. It's real hard (impossible) to play or sing well when what we hear is significantly delayed.

Most users with a reasonably fast PC are able to overdub with the H/W buffer set to 128, which yields acceptably low latency. Super-fast systems can even use 64 reliably, which reduces the latency another 50%.

The automatic adjustment for latency can be easily verified by recording a click on an audio track, patch the output of that track to the input of another track with a cable, record the second track. At the highest buffer setting (where we know there's LOTS of monitor latency), if you zoom way in on both tracks, you'll find the transient still lines up very closely (within about 50 samples). If latency wasn't autocompensated, the second track would be delayed by the amount of your H/W buffer setting.