DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   All Things Audio (https://www.dvinfo.net/forum/all-things-audio/)
-   -   Monitoring Audio? (https://www.dvinfo.net/forum/all-things-audio/524307-monitoring-audio.html)

Jonathan Levin July 29th, 2014 09:17 AM

Monitoring Audio?
Hi All.

Monitoring audio is very important I realize, but it suddenly occurred to me that I may be monitoring incorrectly.

Let's say I have this set up:

A Shure FP33 hooked up to a Marantz PMD660 recorder Nikon D800e DSLR. On the camera there is a mini jack for headphones. Of coarse the mixer AND recorder has a headphone jack too. I normally monitor from the mixer.

On the mixer, there is a Monitor Input Switch:

"In the center position, this
switch sends the post-master audio to the headphone
output. In the left (locking ) or right (momentary) position,
it sends the audio signal from the Monitor In jack
to the headphone output."

and a headphone monitor mode switch:

"The user can monitor the FP33 output as: Stereo; Right
channel only; Mono (Left + Right); or Left channel only.
Note: This switch also affects the Monitor In signal.
When using a stereo MS microphone, such as the
Shure VP88, the user may wish to pass the mic signal
through the FP33 as separate Mid and Side signals,
yet hear decoded stereo in the headphones. Using the
Headphone MS Matrix, the user can monitor the FP33
output as: Discrete (Mid and Side); Side only, Stereo
(decoded MS), or Mono (Mid only). Refer to the Internal
DIP Switch table for instructions on activating the
Headphone MS Matrix.

Honestly, I have never really been sure where these should be set, and all you pro's are probably going WTF?

Maybe someone can clarify this before my luck runs out?

Thanks everyone.


Richard Crowley July 29th, 2014 10:14 AM

Re: Monitoring Audio?
But WHAT are you recording? Are you recording MS stereo music concerts? Are you recording "reality" video with wireless mics? Are you recording scripted drama from a couple of shotgun mics on booms? HOW you use all those monitoring options depends on WHAT you are trying to accomplish.

The reason for the monitor selector switch is so that you can easily monitor the critical points in the audio chain. Namely, the output of the mixer, and the confidence monitor out of the recorder (to confirm it is getting audio properly, etc.)

Jonathan Levin July 29th, 2014 10:36 AM

Re: Monitoring Audio?
Hello again Richard!

Most of what I record are interviews, two, three people either with wired lava and or a Rode NT3.

Your comment on the monitor selection is what I thought.

But that is telling you that there is a signal/audio getting out from the mixer. To me it seems that the audio going into a recording device or camera needs to be monitored as well to make sure that those devices are in fact recording? Or in the field, is just monitoring from the mixer enough? I may be over thinking this..

Richard Crowley July 29th, 2014 11:38 AM

Re: Monitoring Audio?
Note on your FP33 mixer, there is a connector called "MON IN". That is intended to be connected to the headphone out from your recorder. Then you can switch between monitoring the mixer output, and monitoring the output from the recorder (which at least confirms that the audio is getting to the recorder properly).

Jonathan Levin July 29th, 2014 12:56 PM

Re: Monitoring Audio?

Thank you so much!

This is finally making sense to me since I could not figure out how to monitor what was being recorded as well as what is out put from the mixer. Basic stuff I should know!

So just to confirm, I would connect a cable from the headphone jack on my recorder to the MON IN on the mixer, and then use the Monitor Input toggle switch to check audio coming from either mixer or recorder?

If I were to record directly to a camera (I know, two system is better) I would connect a cable to the headphone jack on camera>MON IN on mixer? Correct? In other words, anything feeding into MON IN on mixer is always connected to a headphone out from a camera or recorder?

Thank you sir.


Richard Crowley July 30th, 2014 12:07 AM

Re: Monitoring Audio?
Correct and correct. You got it.

Jonathan Levin July 30th, 2014 10:11 AM

Re: Monitoring Audio?

Can't thank you enough Richard!

Maybe you could comment on this:

In the old days when I had reel to reel Teac and Revox tape decks, there was a tape monitor switch that allowed you to hear what was just recorded to tape, actually listening to audio from tape. Switching back and forth from tap monitor you could actually hear a slight delay or offset.

With todays devices, when you connect to the headphone out from either a camera or recorder are you hearing what is going INTO the recording media or what has just been captured on to that media? Obviously to be able to hear /monitor what is coming FROM the recording media itself is a near certainty that audio is getting saved. Maybe I'm over-thinking this. And I suppose this is different from manufacture, brand quality so on.

And my very last question (I think) I am making a slightly educated guess that when monitoring audio, the volume (gain) your hear in the cans should be about equal when switching back and forth between monitoring audio from recorder/camera and mixer?

Thank you very much again.


Rick Reineke July 30th, 2014 11:48 AM

Re: Monitoring Audio?
"With todays devices, when you connect to the headphone out from either a camera or recorder are you hearing what is going INTO the recording media or what has just been captured on to that media? Obviously to be able to hear /monitor what is coming FROM the recording media itself is a near certainty that audio is getting saved"
- Unless the device has a 'read-after-write' mode (most don't), you're just hearing the audio after the preamp & converter, but not off the media card or drive. Certainly better than nothing.
FWIW, back in the 'old days' an additional 3-head recorder(s) in record/repro mode were commonly used for a 'slap-back echo' effect and/or pre-delay for a reverb device.. as well as other 'flanging' and chorusing effects. No plug-ins, no presets

Jonathan Levin July 30th, 2014 12:48 PM

Re: Monitoring Audio?
Hi Rick,

Thanks for that.

If I recall correctly (and it was the 60's and 70's) the Teac R to R I had did do some echo/reverb effect thing but also had what they called "sound on sound".

Certainly with what I have gained here, my monitoring of audio will be, well, actually monitoring the audio.


Richard Crowley July 30th, 2014 01:41 PM

Re: Monitoring Audio?
The more expensive tape machines had 3 heads (erase, record, play in that order). That would allow you to actually play-back the signal (audio, video, whatever) you just recorded. That was called a "read-after-write" confidence monitor. And typically those machines also had a mode called "E-to-E" (electronics-to-electronics) where you were just monitoring what was coming in. Obviously, monitoring from the playback head would yield NOTHING if the tape wasn't moving.

And, as Mr. Reineke mentioned, because the playback head was a fraction of a second AFTER the recording head, you could use that as a delay-effect. Of course, solid-state devices that use digital memory are used for those kind of delay effects in the modern era.

But in the modern era of recording to digital media (DRAM, flash RAM, hard drives, etc.) you don't really have the concept of separate writing and reading devices, so "read-after-write" is very rare in digital recorders. Of course, since modern digital recording equipment is so much more reliable, most people don't miss the "read-after-write" feature.

Seth Bloombaum July 30th, 2014 02:33 PM

Re: Monitoring Audio?

IIRC, "sound-on-sound" referred to using the record head for playback. When you were building tracks, you wanted to have playback synchronous, not delayed. That is, with 16 tracks, you could lay down drums & bass as your sync reference. Then, switch those tracks to, um... playback from the record head. Now your other performers can listen to the rhythm tracks and lay down their tracks in perfect sync. Teac/Tascam included that feature on 2 and 4 track r/r recorders, though it really comes into its own with 8 or more tracks.

Bill Davis July 30th, 2014 02:48 PM

Re: Monitoring Audio?
In general, you always want to monitor at the END of any audio chain. But inexpensive digital gear can make that difficult.

When tape ruled the audio industry, manufacturers would put a set of playback heads AFTER the recording heads so that a recordist could "confidence monitor" that a clean signal was actually getting printed to the media. That's long gone.

Today, you're arranging digital bits, and to my understanding there isn't a machine made that will allow you to simultaneously write the digital file AND read it instantly after it's written. So you're blocked out of what would be the ideal monitoring situation.

The best you can do is test your recording chain by recording a sample file and playing it back from the recording media listening for any anomalies. Then you just have to trust that if you keep your levels correct, the final recording will be clean.

Modern digital recording processes remind me of the old famous Regan/Gorbechev line - "trust, but verify."

That's the best we can do today.

Simple as that.

Jonathan Levin July 30th, 2014 02:58 PM

Re: Monitoring Audio?
Incredible stuff guys.

Tell me, I've been lusting after a Sound Devices 552 mixer/recorder and I suppose when I win the lottery or have a client that offers to pay above Craigslist wages I'll consider that.

I noticed in the instructions there is no "Monitor In". There is however something called RTN B In. There is also a RTN B/ TC for time code.

I'm guessing that the RTN B IN is the monitor in? There are also a half dozen other inputs that I'll spare you the questions.


Rick Reineke July 30th, 2014 03:26 PM

Re: Monitoring Audio?
"Sound-on-sound" was a generic term. Teac actually used the term "Syml-Sync" for using the record head for playback.. and I recall on my old Teac 3340, one of the first "Syml Sync" machines, had a limited bandwidth and sounded muddy in that mode.. but was adequate to play along with for overdubbing. On the same machine, another variation I used frequency was to lay-down the rhythm tracks, (typically guitar, bass and drums), then pre-mix those three tracks down to one and use the remaining three tracks for vocals, guitars, keys or other. Track sharing was common as well, punching-in a guitar part on a vocal track for instance. Lots of pre-mixing was necessary and not many 'undo' options.
Lester Polsfuss originally experimented with disconnecting a recorder's erase head (and/or putting film over it), and record an additional part 'over the top' of what was there..leaving it intact (somewhat). Les originally refereed to this as "sound-on-sound" ..

Seth Bloombaum July 30th, 2014 06:47 PM

Re: Monitoring Audio?
syml-sync (simul-sync?). That was the word I was looking for - thanks Rick!

"premix three tracks to one..." We called that ping-ponging. How to do an 8-track layup with a 4 channel recorder...

If only there was a way to earn money with my vast store of "vintage" knowledge of workflows gone by... I think I do speak for a lot of old-timers when I say that some of those antique workflows still inform my digital production processes.

The old sync techniques, especially, now seem as if they're from the dark ages. But bring them out and dust them off, add a little digital polish and double-system sound is back bigger than ever. And better, now that digital "transports" don't drift.

All times are GMT -6. The time now is 01:37 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2019 The Digital Video Information Network