HDMI Audio Level?

[Chris Chapman]

HDMI is not my thing, and I'm dealing with figuring out a weird embedding issue:

Vadddio Video System is video output, with video going to BluRay Burner. Audio is coming into the burner off of a seperate mixer. Audio & Video are going into an embedder to get the Audio sync'ed with video. Output from burner is done via HDMI to confidence monitor. Volume on confidence monitor is set to 50%, and audio level is comfortable with a lot of headroom.

When discs are taken to ANY OTHER device, Audio is quiet and we have to go through an extra mix step to boost audio level.

Riddle me this Batman: Why is the Audio level so different? Is it because the Confidence Monitor is a cheap, $90 Walmart special?

The BluRay burner does NOT have an audio level meter to check level, so we are doing everything on the mix side.

Clues for the clueless?

 

[TheaterEd]

I know that with my cheap Television at home, I almost never need the volume above 15 or 20% to hear comfortably, so the fact that you have to turn it up to 50% might indicate that the audio level is always low. I would turn your monitor down to 20% and then adjust the level at the mixer so that you can hear it comfortably with the monitor turned down.

Disclaimer : I'm totally guessing on this, but it sounds right to me.

 

[Chris Chapman]

I used a THX Optimizer and that gave me a MUCH better idea of what is happening on the Monitor side.

 

[Jay Ashworth]

Ah... the Digital Audio Levels fiasco...

The *proper* standard way to deal with digital audio is to place the analog 0VU point at either -20dBFS or -13dBFS on the digital scale when digitizing, *and output it at 0VU when going back to analog*.

A truly surprising number of both devices and processes get that latter one wrong, outputting full scale as 0VU, which leads to the "it's 20dB too quiet" problem you're having.

Somewhere in your workflow, something doesn't understand what the 0VU point should be for digital audio signals, and that's the device you'll have to fix. You usually can't, and *always* don't want to, fix it by screwing with the signal, cause then someone will invariably play it out on a piece of properly configured equipment, and it will blow something out, and you'll get blamed for it.

While that type of situation is often blaming the smart person for being smart, in this case, they'd be right; pre-loading the digital signal to make up for a broken piece of hardware is the wrong solution.

[ Edited to clarify I hadn't got it backwards ]

 

[Chris Chapman]

Jay, could the embedder have a pad on it? Or should I be looking at sub-menus and setup menu of the BD Burner?

 

[Jay Ashworth]

You said the volume on the confidence monitor is ok when set at 50%.

Is that *while you're burning*?

My recommendation is to feed a 0VU kilocycle tone into your burning rig, burn a disc with the setup you use, and then go *rip* the clip, and see what level the recorded digital audio is at.

Off hand, I'm betting against the embedder, but your setup isn't as clear as I'd like for diagnostic purposes. Can you walk through it again, and for each link, describe what sort of cable and signal are involved, and what the connectors at each end are labeled?

Your DVD burner takes analog signals?

 

[museav]

Are the audio signals into the embedder some form of digital or are they analog?

 

[Jay Ashworth]

Late updates, Chris?

 

[Chris Chapman]

Sorry guys, got bogged down in some shows and a build. I've boosted the signal coming from the mixer into the video rig, and that seems to be "better." The mixer for sound is a 4 channel Peavy nightmare, legacy board. Based on the signal strength it is getting, I think I may have to boost the mix from the M7 a touch to get a better level.

General signal path: Source - M7CL, analog send to Peavy mixer, analog into Embedder, digital into BLuRay Burner.

 

[AlexDonkle]

What's the make/model of the embedder?

Assuming the embedder doesn't have a volume trim control of any kind, your best bet is to increase the volume hitting the embedder (in your case, that likely means boosting the volume on your Peavy mixer as you mentioned).