Cross post from Gh2 thread..."Need some audio help"

P

Park Edwards

Veteran
Hello all --

I post here every now and then, chiming in to help others, and I hope some of you can return the favor and help me sort out my Gh2 audio. I just shot a short over the last few weeks and still found my audio to be sufficiently lacking.

Here's a quick setup.
Rode NTG-3
ART USB Dual Pre: http://www.sweetwater.com/store/detail/USBDualPre/
Edirol R 09 recorder: http://www.rolandus.com/products/pro...?ProductId=757
I tried one time to feed the audio from the ART directly into the Gh2 and was too to hot. So I just went to shooting it separately.

Some things I've noticed is the audio is very low. When I monitor, it's very hard to hear. When it's recorder, it's very low. What's the deal? If i turn the gain up too high on the ART, I can hear background noise everywhere, and then the talent gets drowned out. All outdoor shots. What are some solutions? Should I trade in my ART and Edirol and go another route? Ugh, the one thing I have yet to learn and master is the audio aspect of filmmaking. It's so crucial, too. Anyway, go easy on me, explain things like I'm five. Help a buddy out. Thoughts please. If you need, I can upload an audio clip to help give you an idea of what I'm facing.
 
We run multiple outboard audio options with our gh2's, but for ultimate portable outboard recording, I prefer using our tascam dr680 as a portable multitracker. Works well and the audio is first rate. Mic pre's are pretty darn good although the monitoring isn't the best. But with good mics you'll be pleasantly surprised once you dump your audio into your nle.

Also, you set your mic preamp based on your source level which is completely independent of your monitor level. If your recorder doesnt output enough for monitoring purposes, the first place to look is whether you inadvertently backed off the track output in the mixer section of the recorder if it has one. Then check your impedances of your cans vis a vis your monitor output.
 
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Car3o said:
... the audio is very low.
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Under what conditions? Exactly which combination of equipment? Connected how? Powered how? Control settings what?

When I monitor, it's very hard to hear.
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When you monitor where?
Do you have the phantom power turned on at the ART preamp?

When it's recorder, it's very low. What's the deal?
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Connected how? The NTG-3 has XLR output, but the R09 does not appear to have XLR inputs? What kind of cable are you using?
The R09 does not have phantom power for the mic input. How are you powering the NTG-3 (which requires 48V phantom power)?
If you are not providing the NTG-3 microphone with 48V phantom power, the first question is how you are hearing anything at all?


If i turn the gain up too high on the ART, I can hear background noise everywhere, and then the talent gets drowned out. All outdoor shots. What are some solutions? Thoughts please.
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My first guess would be that you aren't providing the NTG-3 microphone with proper phantom power. Do you have the phantom power turned on in the ART preamp? Do you get the green "signal" LED flashing when you speak into the microphone?

I tried one time to feed the audio from the ART directly into the Gh2 and was too to hot.
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The ART appears to have only line-level outputs, and your DSLR camera has only mic-level inputs.
You need to attenuate the ART output back down to mic level to feed your DSLR.

Should I trade in my ART and Edirol and go another route?
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The ARTpreamp should be able to power the NTG-3 microphone properly. You appear to have no other option for powering the NTG-3 microphone.
The Edirol R09 doesn't appear to be doing anything for you unless you feed the audio into it properly.
To feed either the R09 or the DSLR, you need the proper cable to take the output(s) from the ART preamp, attenuate it, and feed it into the 3.5mm mini jack mic input (on the DSLR or the R09).

If you need, I can upload an audio clip to help give you an idea of what I'm facing.
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That is never a bad idea.
 
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The combination of equipment was listed in my initial post. The ART was providing the phantom power. Yes it was on. The mic wouldn't pickup any kind of audio if it wasn't.

The setup goes. NTG-3 into XLR input. A stereo cable from the output into the Edirol's line input.
We monitored the audio from the Edirol, cause it only allows sound through the headphones once it's recording.
The LED lights flicker when there is audio, yes.

Is this the kind of attenuate cable I should get:
http://www.sescom.com/product.asp?item=LN2MIC-ZMH4-GH1&LN2MIC-ZMH4-GH1

Would I feed that directly from the ART into the Gh2?
And is there a less cumbersome battery-powered single channel preamp like the ART that is around the same price?

I was looking at this, but would like something more affordable in my budget:
http://www.bhphotovideo.com/c/produ...evices_MM_1_MM_1_Single_Channel_Portable.html

Here's probably the best clip of them all. The echo was probably due to it being in an alley:
https://docs.google.com/open?id=0B5hXpZ5tKLfTMTZfcmVzcVZUUkE
 
Car3o said:
I tried one time to feed the audio from the ART directly into the Gh2 and was too to hot.
Click to expand...

How much GAIN did you use with your ART pre-amp ?

You should be setting the MIC LEVEL on your GH2 to 1, and then adjust the GAIN of the ART to give you a good audio signal with your NTG-3.

If the signal from your ART is too hot, then you are going to have to add a pad to bring the signal level down to something the GH2 is OK with.

For my GH2 set-up, I use a Sound Devices MixPre to power and amplify my micrphones, and then I feed this at LINE LEVEL from the MixPre to a BeachTek DXA-2S which allows me to adjust the input signal strength to something the GH2 gets along with.

If you were to buy this stuff today, the MixPre is now a "MixPre D" model which can output MIC or LINE level ( so the BeachTek can be skipped if you like ) and the BeachTek DXA-2S is now a "DXA-2T" which is slightly improved.
 
What about monitoring the audio at the ART preamp? How does the signal sound at that point?

Exactly what stereo cable did you use from the ART to the Edirol R09? How do you know it was the right one to use?
From what output of the ART preamp are you getting the audio? From the "headphone" output, or from the "monitor" output?
If you were using the headphone output, did you have the "Mix" control turned all the way to "Preamp" and the "Level" control all the way up?
We don't know any of these things unless you explicitly tell us and guessing is just a waste of time and will get us nowhere.

Can you turn up the gain on the ART to the point where the red "clip" LED flickers? If not, then something is wrong before you even get out of the ART preamp.

You can feed the output from the ART into either (or both) the R09 and the GH2. With the proper cables (and attenuators, etc.) of course.

There is certainly almost nothing better than a Sound Devices product. But you shouldn't need to spend that kind of money to get decent audio signal. There is something more fundamental wrong. Until that is resolved, even a premium Sound Devices preamp won't help you.

As for your sample, how far away was the microphone from the actor? Shotgun mics are not magic wands. If you were more than 18-24 inches away, then you were too far to use a shotgun.
Was the green "SIGNAL" LED on the ART preamp flashing while they were talking? Do you get decent level from the ART preamp before feeding it into the R09 or the GH2?
 
Richard Crowley said:
What about monitoring the audio at the ART preamp? How does the signal sound at that point?

Exactly what stereo cable did you use from the ART to the Edirol R09? How do you know it was the right one to use?
From what output of the ART preamp are you getting the audio? From the "headphone" output, or from the "monitor" output?
If you were using the headphone output, did you have the "Mix" control turned all the way to "Preamp" and the "Level" control all the way up?
We don't know any of these things unless you explicitly tell us and guessing is just a waste of time and will get us nowhere.

Can you turn up the gain on the ART to the point where the red "clip" LED flickers? If not, then something is wrong before you even get out of the ART preamp.

You can feed the output from the ART into either (or both) the R09 and the GH2. With the proper cables (and attenuators, etc.) of course.

There is certainly almost nothing better than a Sound Devices product. But you shouldn't need to spend that kind of money to get decent audio signal. There is something more fundamental wrong. Until that is resolved, even a premium Sound Devices preamp won't help you.

As for your sample, how far away was the microphone from the actor? Shotgun mics are not magic wands. If you were more than 18-24 inches away, then you were too far to use a shotgun.
Was the green "SIGNAL" LED on the ART preamp flashing while they were talking? Do you get decent level from the ART preamp before feeding it into the R09 or the GH2?
Click to expand...


Monitoring from the ART was just as weak as the Edirol.
You ask the questions, I'll answer. I'm learning the ways of the audio. Not trying to waste anyone's time.

I used a standard stereo cable from guitar center. How would I know if it's not the right one?
I'm getting the audio from the monitor outpout and straight into the Edirol.

I will test the red "clip" led function.
The mic was probably 2 feet away.
The green singal was flashing. I don't know what you mean "did I get a decent level from the ART?"
 
Listening to your audio clip, I think the ART pre-amp is likely the weak point in your audio chain. I've used the Rode NTG-3 with my SD MixPre on a few Indie shoots, and the sound I am getting is much "fuller" sounding that what I'm hearing in your clip. ( you clip sounds a "flat" with not a lot of "presence" )
 
Car3o said:
Monitoring from the ART was just as weak as the Edirol.
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What happens if you just sit down at the kitchen table with the NTG-3 and the ART and plug your headphones into the ART monitor jack and the mic into the ART. Aim the microphone at your mouth at a distance of 12 inches and speak in a normal voice. You should be able to turn up the gain on the ART so that the green LED is on solid and the red light flashes. You should get a good loud voice signal in the monitor headphones with very low noise from the ART preamp. If you can't do that then something is wrong with the mic, the cable, and/or the ART preamp. Do you have any other microphones you can test with your ART? Other cables? Other preamps? Do you have any friends with similar equipment that you can borrow to test the various links in your audio chain?

I used a standard stereo cable from guitar center. How would I know if it's not the right one?
I'm getting the audio from the monitor outpout and straight into the Edirol.
Click to expand...

There is no such thing as a "standard cable". There are literally HUNDREDS of variations on what appears to be a simple cable. Until we understand the precise answer to these questions, we are just shooting in the dark.
1) Exactly what cable is it? What kind of connector on each end? How many poles? How is it wired? What is the make and model number? (so we can look it up for you)
2) Which connector do you have it plugged into on the ART preamp?
3) Which connector do you have it plugged into on the R09 recorder?
4) Exactly what are all the settings of the knobs and switches on the ART?
5) Exactly what are all the settings of the knobs and switches on the R09?


What should the gain be at, theoretically?
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If I have to run the gain of something < 30% of the scale, then I start thinking that the input level is getting too "hot" (loud) for the equipment.
If I have to run the gain > 60% then I start looking for the problem in the audio chain.
 
The gain is variable depending on the circumstance, one can't make any generalized rules. Someone need to be looking at a proper set of meters every moment you are recording and riding gain to keep the metered levels in the proper range. What is CRITICAL is the mic to mouth distance. For normal spoken word, the tip of the mic should be no more than about 18 to 22 inches away from the talent's mouth and kept aimed within a circle about 8 inches in diameter centered on the mouth as he moves with the action. With a shotgun you have very little leeway and just a 10 degree or so off-center aiming error will take the subject audibly off-mic. When you said cranking up your gain resulted in excessive background noise, that says the mic is too far away and from its perspective the voice and the noise are about equal in level. Moving the mic closer will increase the level of the voice without increasing the background sounds bleeding in. Also be mindful of noise sources BEHIND the subject - that's why mic are properly positioned just above the frame line so they point down at an angle.
 
Yes, what Steve said. In addition, keep in mind that analog circuits (and mic preamps in particular) have an optimal range of operation. If you must run the gain control very low in the range, you are running the risk of clipping from an input signal that is too hot. And conversely, if you must run the gain control very high in the range, you run the risk of decreasing the signal-to-noise ratio (SNR) and making the circuit noise too prominent in the signal.

Your signal sounds like both improper gain staging (controls not set for optimal operation), and the mic sounds too far away or not aimed properly or the actors are facing in a different direction, etc.

It sounds like you are taking the signal out of the headphone output instead of the proper outputs. Many pieces of audio gear have headphone outputs that are NOT optimized for the cleanest signal (as a cost-saving measure). As a rule of thumb, you can assume that the proper outputs are ALWAYS cleaner than the headphone output from any piece of gear.

Note also that you must have those controls on the back set for maximum signal. The gain controls on the front must be set so that the green LED flashes regularly and you get the very occasional flash of red LED. Then, on the back, the "Monitor Mix" control must be set full over toward "Preamp" (counter-clockwise), and the "Monitor Level" control should (probably?) be set full up (clockwise).
 
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Tonight, or tomorrow, I'll sit down somewhere and do some tests. I do have an Oktava Mk-012. I'll test them both. I don't have any other audio cables available.
I don't know the brand of the cable. I'll try uploading pictures of all the cables and the setup.

A lot of what I'm gathering could be the fault of the boom operator. Even so, I do think the sound from NTG-3 using the ART is softer than my Oktava when it was plugged into a Zoom H4n.
 
Car3o said:
I don't know the brand of the cable.
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You said you bought it at Guitar Center. Go back and look at your receipt and tell us the make and model number. We can figure it out from there.

A lot of what I'm gathering could be the fault of the boom operator.
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It sounds a LOT like the microphone was just not getting enough signal. A shotgun mic is not a magic wand to reach out and grab sound. It does NOT "amplify" sound from the front, it is only better at rejecting sound from the sides. So you still have the effect of distance to deal with no matter what kind of mic you are using.


Even so, I do think the sound from NTG-3 using the ART is softer than my Oktava when it was plugged into a Zoom H4n.
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Your "laboratory" (kitchen table) tests will resolve many questions. Be sure to have the controls on the back set properly or this is all wasted effort.
 
Here's what I wrote to you on the GH2 forum:


Hey man...something doesn't sound right.

I am familiar with all of those products you're using and it should be giving you better results IMHO.
The fact that the audio was too hot going direct into the GH2 but way way low going into the Roland is troublesome to me.
Unfortunately this is the kind of thing that usually has to be troubleshot "hands-on".

Everyone has their own way - but I like to try to eliminate suspects first.
First thing I would want to try is going back to ART-into-GH2. But let's try to lower the incoming gain so as not to overload the GH2. How did you do it?
I would even try using the headphone out. Get a cable that can go from there into the GH2 and then lower the volume with the headphone volume controller on the back of the ART. Once you get it into a non-clipping range - how does it sound?
If it sounds good then there maybe something afoul in your longer signal path.
If you get a louder version of that same "drowned out by the background" sound - then it's your mic technique. You may find that the RODE needs to be much closer than you first thought. OR the polar pattern or "pickup pattern" of the RODE might not be narrow enough for what you're doing.

Why the recorded level is coming out so low on the Roland while that same level overloaded the GH2 is a concern to me...that doesn't sound right. Should there be a difference in level? -Yes....but not THAT much.

EDIT: I see there is only a stereo mini-input for external mics and line-in on the Edirol.
IF...IF you are using this as the input from the ART...then what hole on the ART are you coming out of? And how?
And most importantly...are you SURE that the EDIROL is really recording your RODE? A possibility from the results you described is that the EDIROL is still only recording from its own microphones and NOT your external RODE - that certainly would give you the results you described.
You need to make sure that the EDIROL is properly switching over to your external mic when it records.
 
Car3o, it doesn't matter what level you record at as far as BG noise is concerned. BG noise going to be the same relative to the person speaking. I'm assuming you mean noise in the background, as in cars, birds, people talking. If you mean hiss, then it's not "background" noise, it's "preamp" noise. You should probably keep your recorder's level to 50-60%, as beyond that, noise usually starts to get added. But if your ART is actually giving a clean signal, you could set the recorder lower, and use the ART to boost the gain. Also, remember that you can always turn up the levels in post when you edit. Basically try to have the dialog bouncing around -12db. Also, try to keep the mic within 2 feet of the mouth of the person speaking. The further away you have the mic, the more background gets picked up. Shotgun mics aren't made to allow you to put the mic further away, they are designed to reject sound coming in from the side of the mic. So get that mic over the heads, and point downward for the best results.
 
See, that's what is weird. The noise from the background dropped off when I turned the gain down, and the person speaking stayed relatively the same. Turned the gain up to get a little more from the person speaking, the background noise (cars,traffic) was drowning out the talent. But either way, I'm getting rid of the ART and Edirol and getting a Fostex FR2-LE. I'll have a day where I can work with the boom operator so they know how to better place the mic. It was a learning experience, and the reason why I did this film, to learn. Chadfish, if you would, mind checking out out my other thread about the Fostex and going into cam?
 
When wearing headphones on location, I always think the sound in the background is louder than it ends up sounding when I get in front of my speakers. I think it's an aural illusion! I don't know where your other thread is at, or what the title is.
 
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