YouTube audio not playing on mobile devices??

[Scott Wilkinson]

Apologies if this is a topic that's been beaten to death; I admittedly didn't search the forums because I'm under the gun.

I edited a video in Premiere Pro CC (latest version) with 2 stereo audio tracks. Exported it as H.264 with the YouTube 1080p preset, uploaded to YouTube, and it plays back perfectly both on the desktop and on my iPhone 7.

Now my boss (who is not technologically savvy) is saying the audio doesn't play on her smartphone (no idea what smartphone she has). This completely flabbergasted me!

Some quick googling around revealed that some smartphones with a mono speaker won't properly playback stereo audio tracks from YouTube. (WTF?) In years of video production I somehow have never heard of this issue! (And I'm amazed that current makers of smartphones with a mono speaker don't just automatically mix the stereo track to mono on playback!)

Has anyone else heard of this issue? Does anyone know of a surefire fix that can be done in post-production (Premiere Pro and/or Audition)?

THANKS!
Scott in Eugene, Oregon

[Richard Crowley]

The #1 cause of this problem is that your "stereo" Left and Right tracks are actually the same MONO track, but opposite-phase from each other. They will sound "OK" when played in "stereo", but they will CANCEL each other when combined together and played in MONO!

The most common cause of this problem is using the wrong XLR to 3.5mm TRS adapter on your camera. If you plug a true balanced audio signal into this, the Left channel will record the proper audio signal, and the Right channel will record exactly the same track in the OPPOSITE phase. Thousands of people have been tripped-up by this. You aren't the first (or the 100th or the 1000th).

The simple fix is during editing, select ONLY ONE of the tracks: "Left" or "Right" and throw the other one away. And then ALWAYS check your final edit when played in monaural.

[Scott Wilkinson]

Thanks Richard. I did read something about opposite-phase audio.

As mentioned above, what amazes me is that I've never had this problem before (or at least never had anyone complain they couldn't hear my audio on a smartphone—maybe I got lucky?).

The first fix I just attempted (and waiting to hear the results) was just to create a mono mixdown of all audio tracks in my Premiere project and export that (choosing mono in the export audio options). I think that should work too?

My two original audio tracks were as follows:

Track 1: house audio feed (from the podium mics at a lecture) via 3.5mm stereo cable into my Panasonic Lumix FZ-2500

Track 2: a stereo music track I created myself in Logic Pro

I'm pretty sure the music track (2) isn't the same mono track on both sides (but true stereo). However the house audio track could be...

Scott

[Steven Digges]

I,m sure Richard or others here will correct me if I'm wrong but I think a mix like that was certain disaster. Cross phasing is a scientific principal but, to me, it is a strange phenomena. You can't see it but its there. Often, you can't even create it if you try. But worst of all, by the time you hear it, or someone does NOT hear it, your screwed. Its too late and you have already been bit by it. Head Richards warning, it's real.

If all your boss heard on her phone was silence you may have gotten lucky. She could have heard the music with no voice track from the podium at all. Making it sound like you forgot to include the speech.

Seriously though: To keep from being bit by this I follow good recording rules. I edit on good near-field monitors. THEN I listen to my finished mixes on a crap devices (mono and old lap top) to give it the litmus test before delivery.

Kind Regards,

Steve

[Scott Wilkinson]

From a scientific standpoint this all makes perfect sense. But from a technology standpoint, the fact that this can even still occur is frankly barbaric. LOL I mean, really!?!? This is like a DSLR not actually recording images on the formatted, blank SD card inserted into the camera unless you have to press a button that says "Record to SD card."

ALL recording technology should, by now, be fully tolerant of stuff like this! (Just saying.)

Scott

[Richard Crowley]

What does "tollerant" mean here? What kind of "stuff" are you talking about?
You fell prey to the problem that the 3.5mm TRS connector on your camera is stereo unbalanced, and your feed from the venue system was most likely mono balanced. That means that you were feeding house audio into the left channel, and inverted house audio into the right channel. So when you mix them together, they cancel each other.

You simply need to use the proper adapter when making a connection like that. An adapter wired like the Hosa XVM-101F. It unbalances the incoming audio and feeds the "hot" side to both the tip and the ring so that you get in-phase audio on both Left and Right channels.
Microphone Cable - Hosa Technology

[Rick Reineke]

I've read time and time again, out of phase audio is very common (via Richard's (balanced mono to unbalanced stereo) explanation.

"Does anyone know of a surefire fix that can be done in post-production?".
- Check for mono compatibility either aurally and/or use a hardware or software scope . There is software available as well, standalone and plug-ins..I:ve seen a lot of hardware oscilloscopes on eBay too, but are likely too complex in set-up and use for non-audio folks. Most (pro) DAWs and editors have some kind of basic scope available. The only NLE I'm aware of that has an included scope is Sony Vegas Pro (now by MAGIX Software GmbH) BTW, VP also has a track polarity switch for verification and correction. I don;t know if Auditon has those features, I would hope so. Premiere Pro has only very basic audio tools.

[Bruce Watson]

Originally Posted by Scott Wilkinson

From a scientific standpoint this all makes perfect sense. But from a technology standpoint, the fact that this can even still occur is frankly barbaric. LOL I mean, really!?!?

'Tis a poor workman who blames his tools. Own up to your mistake (most of us have made the same mistake at one time or another), learn from it, and move on. If you're not making mistakes, you aren't trying hard enough.

[Richard Crowley]

The "sure-fire fix in post-production" is pretty simple:
1) NEVER mix together "redundant" tracks. Chose ONE and discard the rest. The "Left" and "Right" side of a "stereo" track is actually two different tracks no matter what it looks like in your edit software. And that goes for redundant lav/boom tracks as well. Of course you can switch BETWEEN them as necessary, but only ONE should be "live" at any given spot in the timeline.
2) Mix down to MONO unless there is some good reason to mix to stereo (or 5.1, etc.)

[Dave Fisk]

is the problem still there if she uses headphones or earbuds?

If it is the phase issue (which it sounds like it is), go back to premiere and get rid of one of the audio channels (if it is dual mono), and just get rid of one of them. Re-export and re-upload to YouTube.

[Jeff Pulera]

If editing in Premiere and you want to use just one side of a stereo track, use the FILL LEFT or FILL RIGHT effect. It will take one side of the mix and copy it to the other, so both the L and R tracks are then identical.

This portable device audio issue has come up many times on the Adobe forum, definitely sounds like a phase issue.

Thanks