headphone audio delay

[tokyofan]

I've go an audio out cable leading from the back of my M-box stretching to a vocal booth nearby and am using a small earphone. But when recording there seems to be a slight delay...almost an echo effect. How can I remedy this. Also, using an RME A/D-D/A converter...should I use the phones out of that instead?

[Ziko]

It sounds like it's the delay caused by your hardware buffer settings.

You've got 2 choices, lower the buffer setting to 128 samples at least, pref 64 and you'll not hear an echo. It'll tax your system more though so if you have a bunch of plugins already running it might struggle.

The other option is to turn on "low latency monitoring" and the delay will dissapear as it will route the audio from the input direct to the monitoring outputs, but this will disable any plugins you have on that track so if you're one for whacking a reverb on some vox you won't hear it if you use this option. A way of getting around this though is to put the verb on an aux channel and bus the vox to it on a send.

[The Dougfather]

You can't lower your buffer on the Mbox and you don't have low latency monitoring.

You need to mute the track you are recording, your hearing a combination of zero monitored and latent digitized signal combined, muting means you will only hear the zero latent track, use the mix knob to adjust the mix between playback and record.

[tokyofan]

I should probably explain the other gear I'm using in conjunction with the Mbox. I'm using a Grace Design preamp and an RME ADI-2 A/D-D/A converter. The Grace runs into the RME's analog inputs. And the RME is connected to the M-box via SPDIF cables. And I'm monitoring out of the MBox's rear headphone jack. So, the M-Box is effectively a dongle.

When the mix knob it turned all the way to the left I get no signal to the headphones. If I turn it up a little I do get a signal but there seems to be a very very short delay. Muting the rec track cuts the signal. Monitoring from the front or back of the Mbox sounds the same. The Grace has no headphone jack. And there's no improvement monitoring out of the RME.
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[The Dougfather]

If i had to guess i would say that the RME is causing latency because of your signal chain, you may need to monitor the inputs directly of the RME via the analogue outputs which then require a mixer to get the Pro Tools playback alongside.

[albee1952]

Ah, the joys of trying to use an Mbox interface with friends...... As you discovered, the MIX knob does not work with the SPDIF input. As much as you enjoy the better sound of bypassing the stock inputs, I would run the Grace straight into the line input of the Mbox and then follow the scenario that The Dougfather laid out. In any case, you should be able to run the Mbox at a buffer setting of 128 which should be acceptable(turn the MIX knob all the way to playback and balance by adjusting the "fader" of your new track. This way, you can do punchins which are tough to do with the recording track muted. If your computer can't handle a 128 buffer, sadly, you really need a more powerful computer.

[The Dougfather]

Albee, i'm not sure how it runs on a PC but on a mac it's nigh on impossible to get the buffer down with an MBox (i assume we're talking original). I can't run mine below 512 and thats even for fairly simple sessions. I normaly run at 1024 for a pain free life, i've heard things have improved slightly on the Mbox2 but how true this is i don't know.

If your using RME kit you might want to consider either an MBox pro or 003. Not sure whats going on at the moment but over here in the UK the 003R seems to be on blow out, i've seen the 003R factory for £719??? It might be because the factory part doesn't mean S@*t now pro tools 8 is released but it's still a good price for the interface alone.