No headphone output ONLY when trying to monitor audio I'm trying to record

[fdean]

Hello everyone,

I have tried looking through the threads to find a solution to this problem. I've seen other threads that are similar, but not my exact problem. If this solution can be found somewhere in the forum and I've missed it, I apologize, and humbly ask for a point in the right direction.

My software and machine and machine specs are below. Today, for some strange reason, I can no longer hear audio in my headphones when I'm trying to monitor audio I want to record (mic and instrument, 1/4" and XLR inputs). The track I want to record on to DOES show a signal, but i can't hear it through my headphones. I CAN, however, hear the monitored signal through my main speakers in my home studio, but not through the headphones (and this does not help when I am portable with my macbook, since I am not connecting to any main speakers). Additionally, I CAN record the audio, and waveforms do show up on the track in edit view as I'm recording. It also plays back fine through my headphones, but no monitoring audio as I am trying to record (or mic check).

I've tried rebooting, shutting off/on the interface (and also tried it with two other regular mboxes with no luck). It has the same problem with any PT project I open, even new ones created specifically to try and solve this problem.

Can someone please help? The school I teach at is getting a recording studio next year, and I have been charged with boning up on PT this summer, as I'll be the main person using/teaching it.

Thanks for any help you can give.

[Top Jimmy]

It sounds like you turned on low-latency monitoring in Pro Tools, but you didn't turn up the input monitoring path in the Mbox Pro control panel. The low latency setting is found in the Options menu. If you can run your hardware buffer size sufficiently low, you don't need to use the low-latency mode. If you can't, enabling the low-latency mode kills the audio through on record enabled tracks and then you control the input monitoring volume in the Mbox Pro control panel.

[fdean]

TOP JIMMY COOKS!!!!
TOP JIMMY SWINGS!!!!
HE'S GOT THE CHOPS!!!!
TOP JIMMY, HE'S THE KING!!!!
THANK YOU!!!!

OK, so that solved it (from one side), BUT revealed another issue. Yesterday, I was working with a recording instructor on a PT project, and the monitoring sound had latency in it. He was the one who suggested enabling "Low Latency Mode". That DID solve the problem with the latency, but later in the day I encountered the problem of no sound coming through when the tracks were record-enabled (which is what led me to this post).

Question 1: Is the latency problem only solved by changing the buffer size, or are there other ways? My buffer size was normally set at 512, and I never had any problems. In order to clear the latency I now have it set at 128.

Question 2: I've never messed with the mbox control panel. I looked at it and couldn't find the input monitoring path (I am using a mic plugged into "Input 4").

I'm sorry for the newbie questions, but that's what I am.... a newbie.

[Top Jimmy]

There's no way for me to know what changed in your setup that led to your problem. What I can tell you is this. PT11 uses a dual-buffering arrangement. Playback tracks all use a large buffer and only the record enabled or live monitoring tracks use the buffer that you determine the size of. I run all day every day at a 64 sample buffer and I have no problems. The plus side of this is that I can monitor through plugins that have little to no latency. If for any reason you can't run at a sufficiently low buffer for live monitoring, you then have to use the low-latency monitoring mode.

Since I don't use the low-latency monitoring mode, I'm not completely intimate with its inner workings between Pro Tools and the 3rd gen Mboxes' control panel and driver. But, after playing around with it for a few minutes, it appears that as long as you have host control enabled in the control panel, Pro Tools is supposed to handle opening the monitoring path in the control panel. If you disable host control, then you have to do it manually. The way it works in the control panel is you select the tab that happens to be your monitoring path and then you can use the faders to turn up any of the inputs to feed directly to the outputs. You'll also see that you have the ability to mix the software returns in the control panel too. If the faders appear to be dimmed, Pro Tools is supposed to be in control of them.

Here's something I noticed while fiddling with things. There was a moment where I was in low-latency mode but it didn't appear that the Pro Tools was opening the channel like it should have. After disabling and re-enabling host control, it appeared to be working correctly. I may or may not have had it set-up properly, but as I continued to fiddle with things, I didn't see this happen again. So, you may have turned up a bug or you may not have things configured correctly. If you continue to get silence when in low-latency mode with host control enabled, report it to Avid. In the meantime, you should be able to disable host control and then you can control the monitoring manually.

[fdean]

Thank you Jimmy. This info is so helpful. I'm creating a personal "troubleshooting" log based on my own encounters. Adding this to it for future reference! Thanks again.

[Kanosan]

I am having this problem as well. PT 12.3.0 on OS 10.11.1 through an mbox pro. I can still see the input signal but cannot hear any sound once low latency monitoring is selected. There appears to be no output detected. I cannot fix this by opening up the control panel and disabling the host control either. With the previous version of PT11 and xbox drivers I was able to get around this by pressing play on the track after enabling LLM. This corrected the problem in the past but is not working with the current version.