Hi,

I've been using an internal audio recording capability on my Canon C100, and it's been fine. I just decided to step up my audio and got myself Sound Devices PreMix 3. I have 2 questions related to general external audio recording, not specific to my recorder.

1. What is the reason for people to hook up the external recorder to the camera? The reviews I've read, the videos I watch all show how to hook up an external audio recorder to the camera but none of them tell me why I would want to do that. Can someone explain the reasons?

2. I'd like to set gain levels on my recorder, from reading blogs etc. I see there are many ways of going about it. It's not just dialing the knob and that's it. There is a way to set the sensitivity and then gain etc. If I just set the knob to about a middle, the microphone has to be right at someone's mouth in order to get adequate levels (I was aiming for between -20 and -12, although in my camera I would normally aim for in between -6 and 0). And that's fine to have it right at their mouth if I'm recording just audio but if I'm also recording a video and use the mic on a boom, no way I can get adequate levels. Can someone tell to me what I'm overlooking?

Thanks

Hello Kathy, this will be an interesting question to read everyone's response on. I also use a C100 and am considering an external recorder.

I don't have much experience with this so I don't have any suggestions other then the external recorder offers greater control, maybe easer control of audio going into the camera.

My question would be; can you get stereo (two channel out) from the recorder into the camera? Or must you do this in post?

Thanks, KPO

My question would be; can you get stereo (two channel out) from the recorder into the camera? Or must you do this in post?

Thanks, KPO
Hi Kevin,

Since you are asking this question, can you tell me what would be the reason to get the audio (regardless of mono or stereo) into the camera? That's actually my question #1.

Hi Kathy,

The main reason for hooking up the external recorder to the camera is that you get better quality pre amps in the external recorder and the mix going into the camera will give you exactly what the premix is hearing, so no sound delay difference that you may get between camera mic and source. Personally I find using an external mix for most of my video work generally not practical, as I don't want to worry about cables, but it is likely to give you the best sound quality directly to the camera. You can of course just use the recording from the Premix and synch it up later which is what I prefer to do.

To use an external Premix input, you need to get the levels to the a premix right first. I would set the output level to 0db, and bring up the input gain until you are getting the correct level on the loudest sound. if there are likely to be some unexpected sudden peaks, back off the gain by a few dB. Once the Premix is set up, you can then adjust the input levels into the camera in the same way.

Some people make the mistake of setting the input gain too high which gives clipping on the input and try to control it by reducing the volume controls. Having the input gain too low results in having to bring up the volume controls which also brings up any system noise. It's always a balancing act to get it right and under ideal circumstances you would have a proper sound check before the main event.

Roger

Hi Kathy,

The main reason for hooking up the external recorder to the camera is that you get better quality pre amps in the external recorder and the mix going into the camera will give you exactly what the premix is hearing, so no sound delay difference that you may get between camera mic and source. Personally I find using an external mix for most of my video work generally not practical, as I don't want to worry about cables, but it is likely to give you the best sound quality directly to the camera. You can of course just use the recording from the Premix and synch it up later which is what I prefer to do.

To use an external Premix input, you need to get the levels to the a premix right first. I would set the output level to 0db, and bring up the input gain until you are getting the correct level on the loudest sound. if there are likely to be some unexpected sudden peaks, back off the gain by a few dB. Once the Premix is set up, you can then adjust the input levels into the camera in the same way.

Some people make the mistake of setting the input gain too high which gives clipping on the input and try to control it by reducing the volume controls. Having the input gain too low results in having to bring up the volume controls which also brings up any system noise. It's always a balancing act to get it right and under ideal circumstances you would have a proper sound check before the main event.

Roger
Thanks Roger but I still don't understand. I understand that the external recorder has better preamps. So, I record to external recorder, then sync in post, that's the way I understand you work with an external recorder. Why are people hooking up the external recorder to the camera, if you hook up the recorder to the camera, are you no longer recording to the external recorder but to the camera? If so, what's the point of having an external recorder if you can go straight to the camera. There is something obvious I don't understand. Do you bypass camera preamp when you connect external recorder to the camera? Is that what I'm missing?

Recording sound separately goes back to film production. With a couple exceptions there was no sound in film cameras, so an independent sound recorder was standard practice.

However, post synchronization had many potential pitfalls. Crystal sync, timecode, bloop lights, sync drift... it was the dark ages by comparison to today’s tools.

This workflow was resurrected for dSLRs to use cheap home studio recorders, and NLE companies responded with plugins and native functions for post sync. But, while these methods are amazing and much more reliable than pre-digital workflows, it is still possible to get into trouble.

You need some sort of recording on the camera to use modern digital post sync. On a dSLR the on-board mic may be very crappy indeed, or, covered by the operator’s hand, or, be too distant to get dialog in a noisy location. If the post sync tools don’t have distinct dialog on-camera, they can’t do their sync magic.

That’s why many people feed their recorder’s output to their dSLR, perhaps with a cable that pads the recorder’s headphone output down to mic level.

And, surprise, some of them found that the resulting camera recording was fine for dialog, or, at least they were satisfied. It depends. Whatever.

In your situation you could run the recorder tethered or untethered from the camera with no special cables, just XLR. You just need to be darn sure you have sound on the camera to sync to later. If I use this workflow at all, I’ll usually go untethered. But recordists are a pretty conservative group, and there’s certainly nothing wrong with a belt and suspenders approach.

(EDIT: 3.5mm output from the mixer, you’d need a 3.5 to XLR, easy to break!)

**********************************
I’ve not used the new SD mixer/recorders, but they look great, SD is (arguably) the best, certainly with the MixPre 3, 6, and 10 they’ve established a new price point for a capable mixer/recorder.

But sensitivity aka. preamp gain aka. trim is pretty much the same across all mixers. Two volume controls for one input channel is confusing. Why would you need that? Think of them as sensitivity (set once for a scene) and fader (ride as needed during a scene).

The purposes of sensitivity / gain are to:
a) set the source’s volume to a level that is good for the performance of the preamp, (which takes your source from mic level to line level inside the mixer), and,
b) set the source’s volume to a level that is good for your control of the mix using the fader, (physical control of the knob when mixing - the knob is somewhere roughly in the middle of its range)

Getting the sensitivity wrong can mean that the preamp is overdriven and the source is distorted. It can mean that you’re trying to set the fader at 0.25 on a 1 to 10 scale. Etc.

Thanks Roger but I still don't understand. I understand that the external recorder has better preamps. So, I record to external recorder, then sync in post, that's the way I understand you work with an external recorder. Why are people hooking up the external recorder to the camera, if you hook up the recorder to the camera, are you no longer recording to the external recorder but to the camera? If so, what's the point of having an external recorder if you can go straight to the camera. There is something obvious I don't understand. Do you bypass camera preamp when you connect external recorder to the camera? Is that what I'm missing?
You would interface with the camera to give yourself a solid source to sync your recorder tracks to. You could use the camera mic for this but you might be too distant from the source and could make it harder to sync due to a more diffuse sound. Think of the MixPre 3 as both a mixer and a recorder. You're sending a mix to the camera to sync to and you're recording separated tracks on the MixPre 3.
If the MixPre3 has a tone generator you use that to calibrate its meters to the cameras meters. The separate recorder gives you more inputs, better control of the levels, better pre amps, and separate audio tracks of each source.
Gain staging is still important so make sure you understand how to optimally set up your recorder's input and then the output will be in the ball park as well. I'm echoing much of what Seth already noted.

Recording sound separately goes back to film production. With a couple exceptions there was no sound in film cameras, so an independent sound recorder was standard practice.

However, post synchronization had many potential pitfalls. Crystal sync, timecode, bloop lights, sync drift... it was the dark ages by comparison to today’s tools.

This workflow was resurrected for dSLRs to use cheap home studio recorders, and NLE companies responded with plugins and native functions for post sync. But, while these methods are amazing and much more reliable than pre-digital workflows, it is still possible to get into trouble.

You need some sort of recording on the camera to use modern digital post sync. On a dSLR the on-board mic may be very crappy indeed, or, covered by the operator’s hand, or, be too distant to get dialog in a noisy location. If the post sync tools don’t have distinct dialog on-camera, they can’t do their sync magic.

That’s why many people feed their recorder’s output to their dSLR, perhaps with a cable that pads the recorder’s headphone output down to mic level.

And, surprise, some of them found that the resulting camera recording was fine for dialog, or, at least they were satisfied. It depends. Whatever.

In your situation you could run the recorder tethered or untethered from the camera with no special cables, just XLR. You just need to be darn sure you have sound on the camera to sync to later. If I use this workflow at all, I’ll usually go untethered. But recordists are a pretty conservative group, and there’s certainly nothing wrong with a belt and suspenders approach.

**********************************
I’ve not used the new SD mixer/recorders, but they look great, SD is (arguably) the best, certainly with the MixPre 3, 6, and 10 they’ve established a new price point for a capable mixer/recorder.

But sensitivity aka. preamp gain aka. trim is pretty much the same across all mixers. Two volume controls for one input channel is confusing. Why would you need that? Think of them as sensitivity (set once for a scene) and fader (ride as needed during a scene).

The purposes of sensitivity / gain are to:
a) set the source’s volume to a level that is good for the performance of the preamp, (which takes your source from mic level to line level inside the mixer), and,
b) set the source’s volume to a level that is good for your control of the mix using the fader, (physical control of the knob when mixing - the knob is somewhere roughly in the middle of its range)

Getting the sensitivity wrong can mean that the preamp is overdriven and the source is distorted. It can mean that you’re trying to set the fader at 0.25 on a 1 to 10 scale. Etc.
Thanks Seth. I would like to record to the recorder and sync in post. I know how to do that and I do know that I still need audio out of the camera for syncing. From the explanations it seems too convoluted to hook up the recorder to the camera, so I will stick with external recording and syncing in post.
I'm still unsure how to set gain/sensitivity. The MixPre can be used in 2 modes BASIC and ADVANCED. ADVANCED more is way more than I need, I don't need a mix, isolated tracks, I don't need to fade. In BASIC mode the knobs are simply "gain" knobs. If I set the gain to the middle of the knob scale, my levels read between -30 and -20 close to -20 most of the time, and that's having the mic right next to the mouth. If I use the mic on a boom the levels read between -40 and -30. That seems wrong to me. Am I overseeing something?

You would interface with the camera to give yourself a solid source to sync your recorder tracks to. You could use the camera mic for this but you might be too distant from the source and could make it harder to sync due to a more diffuse sound. Think of the MixPre 3 as both a mixer and a recorder. You're sending a mix to the camera to sync to and you're recording separated tracks on the MixPre 3.
If the MixPre3 has a tone generator you use that to calibrate its meters to the cameras meters. The separate recorder gives you more inputs, better control of the levels, better pre amps, and separate audio tracks of each source.
Gain staging is still important so make sure you understand how to optimally set up your recorder's input and then the output will be in the ball park as well. I'm echoing much of what Seth already noted.
OK, so I misunderstood, from your explanation I understand that the audio you send to the camera is simply to have a better audio for syncing in post, right?

Hi,

I've been using an internal audio recording capability on my Canon C100, and it's been fine. I just decided to step up my audio and got myself Sound Devices PreMix 3. I have 2 questions related to general external audio recording, not specific to my recorder.

1. What is the reason for people to hook up the external recorder to the camera? The reviews I've read, the videos I watch all show how to hook up an external audio recorder to the camera but none of them tell me why I would want to do that. Can someone explain the reasons?

2. I'd like to set gain levels on my recorder, from reading blogs etc. I see there are many ways of going about it. It's not just dialing the knob and that's it. There is a way to set the sensitivity and then gain etc. If I just set the knob to about a middle, the microphone has to be right at someone's mouth in order to get adequate levels (I was aiming for between -20 and -12, although in my camera I would normally aim for in between -6 and 0). And that's fine to have it right at their mouth if I'm recording just audio but if I'm also recording a video and use the mic on a boom, no way I can get adequate levels. Can someone tell to me what I'm overlooking?

Thanks
Generally you set the fader (the main knob, at 12 o'clock) and dial the sensitivity up until you're getting close to the level you want. Then if you need more or less gain you use the fader to adjust that. It's a two stage input. Think of the sensitivity as coarse gain, and the fader as your smooth adjustment. If the coarse gain is set too low you'll end up with the fader turned way up and it'll get noisy. If the coarse gain is too high the input could distort and the fader will be barely turned up. You want to set it up so you have flexibility from 12 o'clock to about three quarters up on your fader. You can go for the same level on the recorder as you do on the camera as it has a much better audio circuit. If you use tone to line up your recorder meters with the camera meters they should look pretty close to the same and should react about the same. Are you going into the camera at mic level or line level? You could do either one depending on what gives you a more usable signal. If its only for syncing then don't worry too much about it as long as its solid.

Hi Kevin,

Since you are asking this question, can you tell me what would be the reason to get the audio (regardless of mono or stereo) into the camera? That's actually my question #1.

Sorry to high jack your topic. My guess to your question, and I have not read all the response yet, is; It's good to have the exact copy of the audio track your recorder has collected on your camera so you can sync the two in post.

Okay now I'll read everyone response.

Thanks, KPO.

You would interface with the camera to give yourself a solid source to sync your recorder tracks to. You could use the camera mic for this but you might be too distant from the source and could make it harder to sync due to a more diffuse sound. Think of the MixPre 3 as both a mixer and a recorder. You're sending a mix to the camera to sync to and you're recording separated tracks on the MixPre 3.
If the MixPre3 has a tone generator you use that to calibrate its meters to the cameras meters. The separate recorder gives you more inputs, better control of the levels, better pre amps, and separate audio tracks of each source.
Gain staging is still important so make sure you understand how to optimally set up your recorder's input and then the output will be in the ball park as well. I'm echoing much of what Seth already noted.

Generally you set the fader (the main knob, at 12 o'clock) and dial the sensitivity up until you're getting close to the level you want. Then if you need more or less gain you use the fader to adjust that. It's a two stage input. Think of the sensitivity as coarse gain, and the fader as your smooth adjustment. If the coarse gain is set too low you'll end up with the fader turned way up and it'll get noisy. If the coarse gain is too high the input could distort and the fader will be barely turned up. You want to set it up so you have flexibility from 12 o'clock to about three quarters up on your fader. You can go for the same level on the recorder as you do on the camera as it has a much better audio circuit. If you use tone to line up your recorder meters with the camera meters they should look pretty close to the same and should react about the same. Are you going into the camera at mic level or line level? You could do either one depending on what gives you a more usable signal. If its only for syncing then don't worry too much about it as long as its solid.
Hi Bernie, I'm not going to the camera at all.
Also, you said "Are you going into the camera at mic level or line level? You could do either one depending on what gives you a more usable signal. If its only for syncing then don't worry too much about it as long as its solid." I thought that audio was just for syncing, if not, what else can I use that audio for?

Sorry to high jack your topic. My guess to your question, and I have not read all the response yet, is; It's good to have the exact copy of the audio track your recorder has collected on your camera so you can sync the two in post.

Okay now I'll read everyone response.

Thanks, KPO.
I see, I use internal speakers on the camera for syncing, never had issues. And if the only reason to have the recorder hooked up to the camera so you get a copy of audio in your camera for syncing purposes, why would you care whether it's stereo or mono?

...I'm still unsure how to set gain/sensitivity. The MixPre can be used in 2 modes BASIC and ADVANCED. ADVANCED more is way more than I need, I don't need a mix, isolated tracks, I don't need to fade. In BASIC mode the knobs are simply "gain" knobs. If I set the gain to the middle of the knob scale, my levels read between -30 and -20 close to -20 most of the time, and that's having the mic right next to the mouth. If I use the mic on a boom the levels read between -40 and -30. That seems wrong to me. Am I overseeing something?
Not having used this mixer, and not having time to research, I’ll speculate. Take it for what it’s worth.

If the BASIC mode really does turn the knobs into pre-preamp gain controls (trims, sensitivity) then crank them up so your peak volumes hit -18db, or, -12db, depending on how adventurous/conservative you are.

Test and listen... for corporate talking heads (do I remember that’s a lot of what you do?) I’d peak at -12db.

Running faders at about 12 o’clock is for faders, not preamp gain! You’re saying you can make the knobs into gain controls? Run them right up past 12, way past as needed.

PS. That’s a very interesting function SD has put in. I like it!

I see, I use internal speakers on the camera for syncing, never had issues. And if the only reason to have the recorder hooked up to the camera so you get a copy of audio in your camera for syncing purposes, why would you care whether it's stereo or mono?

Your right, now that I have read all the feedback I only need one channel or mono into the camera to sync in post.

Thanks, KPO.

Sorry to high jack your topic. My guess to your question, and I have not read all the response yet, is; It's good to have the exact copy of the audio track your recorder has collected on your camera so you can sync the two in post.

Okay now I'll read everyone response.

Thanks, KPO.

Not having used this mixer, and not having time to research, I’ll speculate. Take it for what it’s worth.

If the BASIC mode really does turn the knobs into pre-preamp gain controls (trims, sensitivity) then crank them up so your peak volumes hit -18db, or, -12db, depending on how adventurous/conservative you are.

Test and listen... for corporate talking heads (do I remember that’s a lot of what you do?) I’d peak at -12db.

Running faders at about 12 o’clock is for faders, not preamp gain! You’re saying you can make the knobs into gain controls? Run them right up past 12, way past as needed.

PS. That’s a very interesting function SD has put in. I like it!
From the manual
"In Basic mode, the MixPre-3 functions as a two-track 48 kHz recorder. The two record tracks are fed by the LR mix which is driven directly by the channel knob gains"
OK so if I run past 12 the audio is not very clean any more (but maybe I'm getting confused by the room tone)

As long as you have both pieces of equipment, sync the two of them. Its easier than it sounds. One of the biggest reason for this is, at least for me, is redundancy. It’s a very bad feeling to get back to post and find no audio recorded on your sd card.

As long as you have both pieces of equipment, sync the two of them. Its easier than it sounds. One of the biggest reason for this is, at least for me, is redundancy. It’s a very bad feeling to get back to post and find no audio recorded on your sd card.
But what would be the reason it didn't record on SD? You didn't press the record button? If so, does it still send signal to camera even if you didn't hit record?

From the manual
"In Basic mode, the MixPre-3 functions as a two-track 48 kHz recorder. The two record tracks are fed by the LR mix which is driven directly by the channel knob gains"
OK so if I run past 12 the audio is not very clean any more (but maybe I'm getting confused by the room tone)
I’d really need to have hands-on time with the thing to give good guidance.

Sound Devices doesn’t seem to have published a block diagram for this, probably because of all the choices between basic, advanced and custom modes.

Gain is a genaric term that can be applied at any stage of amplification. Just do stay aware of the different functions between preamp gain/trim/sensitivity and fader gain.

If you take your quieter and louder clips into your NLE, you can boost the quieter to the same level as the louder clip. Then you can compare room tone and other sources of noise.

I’d really need to have hands-on time with the thing to give good guidance.

Sound Devices doesn’t seem to have published a block diagram for this, probably because of all the choices between basic, advanced and custom modes.

Gain is a genaric term that can be applied at any stage of amplification. Just do stay aware of the different functions between preamp gain/trim/sensitivity and fader gain.

If you take your quieter and louder clips into your NLE, you can boost the quieter to the same level as the louder clip. Then you can compare room tone and other sources of noise.

I just did this test. I'm not in a sound proof room. What does this tell me?

OK, so I misunderstood, from your explanation I understand that the audio you send to the camera is simply to have a better audio for syncing in post, right?
Exactly! But if you have a circumstance that you have a quick turn around and you don't have time to go through the sync process your camera tracks should still sound better with the Mix Pre feeding the camera because of the superior preamps.

OK, so I misunderstood, from your explanation I understand that the audio you send to the camera is simply to have a better audio for syncing in post, right?

I just did this test. I'm not in a sound proof room. What does this tell me?
From the sound of it I only hear ambient room noise. If the pre amps were getting noisy you would hear a consistent hiss in the background. It would help to know how you set up your test and what components were used.

You haven't given any information to go on. How is your test set up and what components are involved?

I did what Seth suggested
If you take your quieter and louder clips into your NLE, you can boost the quieter to the same level as the louder clip. Then you can compare room tone and other sources of noise.

Exactly! But if you have a circumstance that you have a quick turn around and you don't have time to go through the sync process your camera tracks should still sound better with the Mix Pre feeding the camera because of the superior preamps.
So what happens with the preamp on the camera, does it get turned off? That's the part I don't understand. How is it sending the audio from the external recorder better than if I hooked up the same mic directly the camera??? Does the camera know not to use its preamp? I understand the difference between the audio recorded to the camera vs recorded to the external recorder but I don't understand how different it is when you are sending it from the recorder to the camera unless what I said it's true that the camera's preamp somehow is not involved any more.

So what happens with the preamp on the camera, does it get turned off? That's the part I don't understand. How is it sending the audio from the external recorder better than if I hooked up the same mic directly the camera??? Does the camera know not to use its preamp? I understand the difference between the audio recorded to the camera vs recorded to the external recorder but I don't understand how different it is when you are sending it from the recorder to the camera unless what I said it's true that the camera's preamp somehow is not involved any more.
Your camera has a mic or line input. When I feed a camera from a mixer/recorder I always use line in if I can. Theoretically this does bypass the mic preamps in the camera. I say theoretically because some so called line inputs are simply padded down mic inputs. Even if that's the case going in line is better because you're by passing all of the mic controls that are in the menu and aren't needed because you have the Mix Pre getting the mic signal.
This is all moot if you simply want to sync using the camera mic as a reference, but if you want a high quality recording on both your camera and Mix Pre then you should experiment with setting the levels so you're satisfied with both recordings.

Your camera has a mic or line input. When I feed a camera from a mixer/recorder I always use line in if I can. Theoretically this does bypass the mic preamps in the camera. I say theoretically because some so called line inputs are simply padded down mic inputs. Even if that's the case going in line is better because you're by passing all of the mic controls that are in the menu and aren't needed because you have the Mix Pre getting the mic signal.
This is all moot if you simply want to sync using the camera mic as a reference, but if you want a high quality recording on both your camera and Mix Pre then you should experiment with setting the levels so you're satisfied with both recordings.
In Basic mode you can only record two tracks which are also bused to the LR output. That's great if you only have two sources. If you want isos of three sources plus a LR mix then you have to use advanced mode. Advanced gives you more control over the gain staging and limiter settings as well. Nice little unit! Good luck with it!

From the sound of it I only hear ambient room noise. If the pre amps were getting noisy you would hear a consistent hiss in the background. It would help to know how you set up your test and what components were used.
Hi Bernie,
I just plugged in a mic into one of the XLR inputs and recorded ambience. The gain on the first recording was set to about 3 o'clock, and the second recording had gain level set to 12 o'clock. That's all.

Your camera has a mic or line input. When I feed a camera from a mixer/recorder I always use line in if I can. Theoretically this does bypass the mic preamps in the camera. I say theoretically because some so called line inputs are simply padded down mic inputs. Even if that's the case going in line is better because you're by passing all of the mic controls that are in the menu and aren't needed because you have the Mix Pre getting the mic signal.
This is all moot if you simply want to sync using the camera mic as a reference, but if you want a high quality recording on both your camera and Mix Pre then you should experiment with setting the levels so you're satisfied with both recordings.
I see, I will have to test that. Thanks. How do you monitor the sound? Do you listen to the recording on the external recorder or the one on the camera?

In Basic mode you can only record two tracks which are also bused to the LR output. That's great if you only have two sources. If you want isos of three sources plus a LR mix then you have to use advanced mode. Advanced gives you more control over the gain staging and limiter settings as well. Nice little unit! Good luck with it!
I don't understand this. I have 3 XLR inputs on the mixpre, so if I'm in BASIC mode, do I not get 3 separate tracks if I have 3 inputs? Maybe I'm confusing track and channel?

I don't understand this. I have 3 XLR inputs on the mixpre, so if I'm in BASIC mode, do I not get 3 separate tracks if I have 3 inputs? Maybe I'm confusing track and channel?

Hi Kathy,

I don't have the premix, but the number of inputs is irrelevant to the premise. I have an 8 input mixer which will also record to two output tacks. On a mixer of any sort, you will have input channels which will either just have a simple gain or volume control on each input channel or other controls such as eq which may either be in the form of control knobs or switches, or set from accessible menus.

The input channels will be routed after mixing to the output bus which could be just one on a mono mixer, two on a stereo mixer or more on a multi output buss mixer. Most mixers will also have some sort of 'Pan' control, which is basically to vary the amount going to each output channel. so anticlockwise will send the signal to the left output buss, clockwise to the right output buss and centre equally to both. In a multi output buss mixer, you would have a further switch to send each channel to the output pair that you want.

If the mixer also includes a built in recorder, like the Premix, there will be a fixed number of record 'Tracks'. So a stereo recorder will just have two record tracks and it will be up to the user to route each channel output to the left and right outputs and record tracks depending on where in the stereo image they want each channel to appear. If you are just using two mics, they could be recorded with one on each track, or both equally on both tracks if you wanted, or offset slightly between left and right. The more input channels you have depending on the mixer, the more you can vary your mic positions in the stereo image.

If the Premix only has two record tracks but 3 mic inputs, you just need to decide where to arrange each mic in the stereo image. If it has three record tracks, then you can record them all separately if you want. I should also say that some recorders have paired tracks so that you can make two identical recordings at different levels as a backup.

This is why you see audio recorders listed as stereo(2 tracks) 4 tracks, 6 track etc. If you are a multi mic user, the the more record tracks you have, the more you can change things at the editing stage.

Hope you are not even more confused now,

Roger

Hi Kathy,

I don't have the premix, but the number of inputs is irrelevant to the premise. I have an 8 input mixer which will also record to two output tacks. On a mixer of any sort, you will have input channels which will either just have a simple gain or volume control on each input channel or other controls such as eq which may either be in the form of control knobs or switches, or set from accessible menus.

The input channels will be routed after mixing to the output bus which could be just one on a mono mixer, two on a stereo mixer or more on a multi output buss mixer. Most mixers will also have some sort of 'Pan' control, which is basically to vary the amount going to each output channel. so anticlockwise will send the signal to the left output buss, clockwise to the right output buss and centre equally to both. In a multi output buss mixer, you would have a further switch to send each channel to the output pair that you want.

If the mixer also includes a built in recorder, like the Premix, there will be a fixed number of record 'Tracks'. So a stereo recorder will just have two record tracks and it will be up to the user to route each channel output to the left and right outputs and record tracks depending on where in the stereo image they want each channel to appear. If you are just using two mics, they could be recorded with one on each track, or both equally on both tracks if you wanted, or offset slightly between left and right. The more input channels you have depending on the mixer, the more you can vary your mic positions in the stereo image.

If the Premix only has two record tracks but 3 mic inputs, you just need to decide where to arrange each mic in the stereo image. If it has three record tracks, then you can record them all separately if you want. I should also say that some recorders have paired tracks so that you can make two identical recordings at different levels as a backup.

This is why you see audio recorders listed as stereo(2 tracks) 4 tracks, 6 track etc. If you are a multi mic user, the the more record tracks you have, the more you can change things at the editing stage.

Hope you are not even more confused now,

Roger

Well, you just got me mildly confused! Here is the thing. All I want to do, for now, is to record 2 people. They each have their own lavs and I want to get a mono recording of each. I want to end up with two files, with mono recordings of each speaker. Really simple. I'm not mixing anything on a fly, I don't need to do anything fancy. Is there something I need to know about tracks and buses to get this accomplished?

I see, I will have to test that. Thanks. How do you monitor the sound? Do you listen to the recording on the external recorder or the one on the camera?
You could monitor in either place. If you're going to use the camera tracks and not sync, monitor on the camera. If you're going to sync the recorder tracks, first make sure you're getting a good signal into the camera to sync to, and then monitor the recorder.

I don't understand this. I have 3 XLR inputs on the mixpre, so if I'm in BASIC mode, do I not get 3 separate tracks if I have 3 inputs? Maybe I'm confusing track and channel?
In Basic mode you can plug in three sources but it records to two tracks only. So each one would need to be panned left, right, or center. So you're doing a LR mix of three sources and recording it and/or outputting it to your camera.
To record three separate tracks you have to use the Advanced mode. That would give you the three isolated sources plus a LR mix if you want it. So five tracks total. Channels are what you plug your sources into, tracks are what you can record to.

In Basic mode you can plug in three sources but it records to two tracks only. So each one would need to be panned left, right, or center. So you're doing a LR mix of three sources and recording it and/or outputting it to your camera.
To record three separate tracks you have to use the Advanced mode. That would give you the three isolated sources plus a LR mix if you want it. So five tracks total. Channels are what you plug your sources into, tracks are what you can record to.
Thank you, that makes sense. Here is another question if I have two inputs (two lav mics) and I'm in Basic mode, do you get one file with two tracks (one lav on one track and the other lav on the other track) or do I get both inputs mixed into both tracks or do I get two separate files (each having two tracks with one lav on each track)?

Well, you just got me mildly confused! Here is the thing. All I want to do, for now, is to record 2 people. They each have their own lavs and I want to get a mono recording of each. I want to end up with two files, with mono recordings of each speaker. Really simple. I'm not mixing anything on a fly, I don't need to do anything fancy. Is there something I need to know about tracks and buses to get this accomplished?

Hi Kathy,

I can not answer your questions entirely. The scope of your answer is not simple and beyond a short forum post. What you are asking is really about "How do I learn proper gain staging and record good interview audio?" There are books written about it and operators who spent years to understand that. I am familiar with your posts on this forum and the tools you use. You are on the right track to achieving your goal. I believe your frustration is coming from a lack of understanding audio for video in general. No one on this forum will be able to tell you exactly how to set up your Sound Devices MixPre-3 and Canon C100 so that it will be simple and work every time for a two person interview. There is much more to it than that. I am not writing to be critical in any way. I have seen you work through several other things you wanted to lean on this forum. I know you always figure out a solution that works for you in the end. I think I can make a couple of comments to help you avoid a disaster in the future.

First, your goal of an end result with with two separate mono tracks from two lavs is very attainable with the tools you have. It can be done, and should be done, in my opinion with the end result recorded in the camera. The MixPre-3 records should be your backup records, not the other way around.

Please let me explain how I THINK about audio flow. I think of all audio in terms of signal flow. That is the name of the game. Then I plan a backup system for all audio records. Next I consider workflow.

Signal flow is about following, directing, and manipulating the source all the way to the recorded result. In other words, where is it going and what are you doing to it on the way. Your signal flow is this: Spoken word (X2) - Lavs (X2) - Mixer/ Recorder (do not stop there) - Camera, final destination, one lav on Right, one on Left. Result: Quality record in camera and separate files for backup recorded by Mixer/Recorder and a simple post production workflow.

Just because you purchased a quality off camera recorder does not mean you should disregard your cameras audio recording capability. The downfall of camera recording is their preamps, not the signal they record. When fed a proper robust signal most cameras will record very good audio. It seems to me you are disregarding the "Mixer" side of your MixPre-3 and it is a very good mixer with preamps that far exceed you C100s ability. Just one of the areas this can greatly improve your audio is anytime you need to boost a signal above average you can do it with the MixPre-3 superior preamps and not introduce noise at the camera. When booming this is critical. Even a soft talker on a lav requires additional gain. This should all take place on the mixer.

Avoiding disaster? You mentioned the possibility of forgetting to hit record on the MixPre-3. You may think that could never happen to you. I have seen it happen with devastating results to some very competent technicians. It does not happen to me. Am I so good I could never forget? Absolutely not! It does not happen to me because I know it could so I build backup systems into my signal flow. Thinking of your C100 audio as a sinc track only is dangerous. Especially when all you need to do is feed it a good signal. It records audio everytime you hit record, no extra step necessary.

You said "using advanced mode on the MixPre-3 is beyond your understanding". I suggest you learn to understand it. I know you want a simple answer to your post that tells you how to do it. Instead all can offer is a way of thinking about how to achieve your goal. You have great tools to work with. They can do it if you learn to understand them. Start basic and learn advanced until you can adapt to any situation.

Kind Regards,

Steve

Hi Kathy,

Steve is absolutely correct, you have the tools to do the job well, but are lacking in the background knowledge to understand how to use them correctly. You need to understand more about the sound itself and how to to get the best from your equipment. That is not something that can be picked up from a few forum questions and you need time to understand and absorb. It is very easy to to do a worse job with better gear just by using it incorrectly.

As Steve said, the ideal situation is getting the best possible sound recorded on the camera, but you could equally come unstuck trying to achieve it. Although I have various mixers and recorders, I film mainly weddings and don't have time at a wedding to set up levels between equipment, or the ability to run cables in most instances. To that end I keep it absolutely basic with a very small pocket recorder and lav for the speakers. I have a number of these https://www.amazon.co.uk/Sony-ICD-PX312-Digital-voice-recorder/dp/B004SO9604/ref=sr_1_1?ie=UTF8&qid=1511000680&sr=8-1&keywords=sony+icd-px312
For your two person interview, I would put a lav on each person and a recorder in an inside pocket or similar, put them into record 15 minutes early and forget about them. Then in post cut out the first 15 minutes of garbage and sync the two tracks to the sound from the camera mic.

Using that method, the sound will be consistent and pretty much foolproof. I would learn a lot more about audio before using the Premix in a situation where you could get it wrong, but you have some great gear once you are familiar with it. Audio is frequently one of those things that is often overlooked by videographers but is as important and sometimes more so than the video.

Roger

Thank you, that makes sense. Here is another question if I have two inputs (two lav mics) and I'm in Basic mode, do you get one file with two tracks (one lav on one track and the other lav on the other track) or do I get both inputs mixed into both tracks or do I get two separate files (each having two tracks with one lav on each track)?
I'm guessing it will be a poly file which will be a single file that has two separate tracks. What goes to each track would depend on your left, right, or center panning. For two sources you would pan one left and one right. If you panned either source to the center then that source would go to both tracks. If it isn't a poly file then it would appear as two separate mono files which would have the exact same start time. I suggest you do some test recordings, import them into your edit system and see how they look. I'm sure its in the manual but I don't have time to look it up.

Steve and Roger make some good points but ultimately it all really depends on the workflow that works the best for you. Most importantly you need to know your gear and how to get the best performance out of it. You do that by reading the manual, asking questions, and then experimenting before taking it out on a real job. If you get comfortable with it in a low stress environment then you minimize potential mistakes.
There are many ways to get the job done, but what works the best for you is the right one.

#1 reason to use an external recorder and not just the camera itself: as doing sound is a full time job in its own right! (usually several full time jobs!)

Thus is a terrible compromise to make the cameraman do sound as well.

Kathy, if you go to YouTube there are some very good reviews/tutorials about the MixPre series that may answer some of your questions.

Why record to a multi track recorder?
You may only input two channels (tracks) to your camera, but depending upon the NLE you use, you may be able to import any number of tracks.
The advantage of using the MixPre is that once you have imported the MixPre recorded tracks into the NLE, you can edit (manipulate) the content of each individual track to obtain the best possible audio to accompany the video.
Maybe one of your narrators has a cough. You can edit that portion of the audio out of that track and have a cleaner sounding track. You could delete the cough audio and replace it with an equal duration of the empty room noise you recorded for just such a purpose. This way, you would not hear a drop out that a flat line waveform produces.
Maybe you want to have a narrator dub an audio track for a slideshow. Just use the recorder with a mic as the narrator describes each slide. [https://vimeo.com/193752056]
You can even have multiple narrators.