Mixer, and recorder - questions [noise problem]

TheNoob · Jul 27, 2015

Any comment, suggestion or help is appreciated! But as my name suggest..proceed with caution.

Background: I have no experience with audio equipment.

Mixer: Sound devices Mix-Pre D.
Recorder: Marantz PMD661.
Mics: Sennheiser K6/ME66, and a Rode Lav.

Questions 1 - Audio in post [noise reduction]: Can I do something in post to help my audio in terms of noise reduction?

Questions 2 - Audio signal [noise reduction]: Can I do something while I am recording to get less noise?

Question 3 - Why am I getting so much noise?

soundslikejoe · Jul 27, 2015

Questions 1 - Audio in post [noise reduction]: Can I do something in post to help my audio in terms of noise reduction?
Answer 1 - Yes

Questions 2 - Audio signal [noise reduction]: Can I do something while I am recording to get less noise?
Answer 2 - Yes

Question 3 - Why am I getting so much noise?
Answer 3 - See section of original post titled "Background"

Jokes aside... You'll need to give more detail. What type of noise? Hum? Buzz? Ambient location sound that's too loud? What are you recording? Can you post a clip? Etc.

TheNoob · Jul 27, 2015

soundslikejoe said:
Questions 1 - Audio in post [noise reduction]: Can I do something in post to help my audio in terms of noise reduction?
Answer 1 - Yes

Questions 2 - Audio signal [noise reduction]: Can I do something while I am recording to get less noise?
Answer 2 - Yes

Question 3 - Why am I getting so much noise?
Answer 3 - See section of original post titled "Background"

Jokes aside... You'll need to give more detail. What type of noise? Hum? Buzz? Ambient location sound that's too loud? What are you recording? Can you post a clip? Etc.

It is not ambient noise. I am recording dialogue. It is noise as in *hisssssss* during quiet periods *hisssssss* << sounds exactly like that actually. I will upload a clip later. I am not home... at the moment. But hopefully a sound clip will be more useful than my gibberish non-sense talk.

soundslikejoe · Jul 28, 2015

Yep. Sound clip would help. The *hisssssss* you describe is exactly what an air conditioner sounds like during recording. Did you shut off the AC? Could be a million other things too.... Could be preamp noise if the SDevices was cranked to max.

trueindie · Jul 28, 2015

He's probably just recording directly into his camera. Some of the cameras we buy at the lower prices introduce artificial audio gain to differentiate from higher priced models.

If this is the case, and you're using canon products, just install magic lantern and it'll get rid of the hiss during the quiet periods.

TheNoob · Jul 28, 2015

soundslikejoe said:
Yep. Sound clip would help. The *hisssssss* you describe is exactly what an air conditioner sounds like during recording. Did you shut off the AC? Could be a million other things too.... Could be preamp noise if the SDevices was cranked to max.

It's not ambient noise. The place I am recording in is completely quiet aside from a clock ticking. The SD is not cranked up to the max either. The dial is at 9 o'clock and 6 o'clock is muted.

trueindie said:
He's probably just recording directly into his camera. Some of the cameras we buy at the lower prices introduce artificial audio gain to differentiate from higher priced models.

If this is the case, and you're using canon products, just install magic lantern and it'll get rid of the hiss during the quiet periods.

I have my MixPre-D connected to my Marantz via digital in. It is AES3 to S/PDIF. I will record and upload 3 clips after I finish my breakfast.

1. MixPre-D to Marantz Via XLR to RCA
2. MixPre-D to Marantz via XLR to XLR
3. Marantz only with XLR output from Rode lavalier.

TheNoob · Jul 28, 2015

TheNoob said:
I have my MixPre-D connected to my Marantz via digital in. It is AES3 to S/PDIF. I will record and upload 3 clips after I finish my breakfast.

1. MixPre-D to Marantz Via XLR to RCA
2. MixPre-D to Marantz via XLR to XLR
3. Marantz only with XLR output from Rode lavalier.

Here it is guys! I recorded these under the best conditions at the time. So tell me what you guys think and of course any feedback is appreciated. Thanks for giving it an ear. And I apologize on the third video! I just couldn't stop laughing after I got a bit tongue twisted.

1. https://www.youtube.com/watch?v=YUGgy9z032Y
2. https://www.youtube.com/watch?v=6XwhseZWWGo
3. https://www.youtube.com/watch?v=tjdx7WwUBH8

AudioPostExpert · Jul 28, 2015

TheNoob said:
Questions 1 - Audio in post [noise reduction]: Can I do something in post to help my audio in terms of noise reduction?

Questions 2 - Audio signal [noise reduction]: Can I do something while I am recording to get less noise?

Question 3 - Why am I getting so much noise?

1. Yes. there are some relatively cheap noise reduction tools all the way up to very expensive ones. The most expensive ones tend, unsurprisingly, to be the best most of the time.

2. In no particular order: A. Better quality of mics, B. Better mic placement/positioning and C. Better locations (sound blankets next to reflective surfaces, all electrical devices/machines switched off, etc.).

3. I wouldn't say you were getting SO much noise but what you are getting is mainly a combination of the items listed in #2. Note that there will always be some noise, even with the best mics, perfectly positioned in a recording studio but obviously there will be significantly less noise.

G

TheNoob · Jul 28, 2015

AudioPostExpert said:
1. Yes. there are some relatively cheap noise reduction tools all the way up to very expensive ones. The most expensive ones tend, unsurprisingly, to be the best most of the time.

2. In no particular order: A. Better quality of mics, B. Better mic placement/positioning and C. Better locations (sound blankets next to reflective surfaces, all electrical devices/machines switched off, etc.).

3. I wouldn't say you were getting SO much noise but what you are getting is mainly a combination of the items listed in #2. Note that there will always be some noise, even with the best mics, perfectly positioned in a recording studio but obviously there will be significantly less noise.

G

Which one would you say sounded best? And do you think what I have recorded could be edited in post to sound significantly better if I use any noise reduction tools? Or does this sound acceptable for a Rode lav in context to a low to no-budget short film around 5 - 8 min long? Also I've never used a mixer before so is it acceptable to adjust input gain while their is no dialogue being spoken to lower noise during quiet periods?

EDIT 1: for clarity

AudioPostExpert · Jul 28, 2015

TheNoob said:
Which one would you say sounded best?

Impossible to say. The background noise is different each time, not because of how you have your equipment connected but because the background noise of what you are recording is different each time!

TheNoob said:
And do you think what I have recorded could be edited in post to sound significantly better if I use any noise reduction tools?

NR is usually applied during sound mixing rather than sound editing but yes, skilled sound editors and mixers with the right equipment would make a significant improvement. Less skilled editors/mixers with lesser equipment would obviously make a less significant improvement.

TheNoob said:
Or does this sound acceptable for a Rode lav in context to a low to no-budget short film around 5 - 8 min long?

Depends what for. For Youtube yes, for a top film festival no.

TheNoob said:
Also I've never used a mixer before so is it acceptable to adjust input gain while their is no dialogue being spoken to lower noise during quiet periods?

Yes it is acceptable under those conditions but not for the reason you have stated. If an adjustment needs to be made due to some severe change in volume of what you're recording then doing it during a quiet period would be the best place. If an adjustment doesn't NEED to be made then don't make one. A consistent noise level is much easier to deal with in post than an inconsistent one. What you could do if you were so inclined, is change the output level of the Mix-Pre D to your camera during the quiet sections, to lower the noise but record the un-lowered signal to your Marantz. Thus giving you both options come post-prod.

G

soundslikejoe · Jul 28, 2015

Some of that noise is definitely environmental. I hear the noise level of the equipment, but there is something else in there that is mechanical.... like HVAC or a refrigerator in another room... or something.

But... I liked both examples with the MixPreD... #1 prob was best based on a quick choice.

TheNoob · Jul 28, 2015

AudioPostExpert said:
Impossible to say. The background noise is different each time, not because of how you have your equipment connected but because the background noise of what you are recording is different each time!

Haha! I tried my best!

AudioPostExpert said:
NR is usually applied during sound mixing rather than sound editing but yes, skilled sound editors and mixers with the right equipment would make a significant improvement. Less skilled editors/mixers with lesser equipment would obviously make a less significant improvement.

I will try and hone my audio skills. I mean, I'm basically just using the input gain and headphone gain dials. I'm sure their are more features I could use to help reduce noise? Maybe. I will study my equipment better!

AudioPostExpert said:
Depends what for. For Youtube yes, for a top film festival no.

Yes, for youtube! At least for now...

AudioPostExpert said:
Yes it is acceptable under those conditions but not for the reason you have stated. If an adjustment needs to be made due to some severe change in volume of what you're recording then doing it during a quiet period would be the best place. If an adjustment doesn't NEED to be made then don't make one. A consistent noise level is much easier to deal with in post than an inconsistent one. What you could do if you were so inclined, is change the output level of the Mix-Pre D to your camera during the quiet sections, to lower the noise but record the un-lowered signal to your Marantz. Thus giving you both options come post-prod.

G

Mmm, okay. I understand.

TheNoob · Jul 28, 2015

soundslikejoe said:
Some of that noise is definitely environmental. I hear the noise level of the equipment, but there is something else in there that is mechanical.... like HVAC or a refrigerator in another room... or something.

But... I liked both examples with the MixPreD... #1 prob was best based on a quick choice.

Yes, that's my fridge!

but the main noise is coming from my equipment. Which is what I am trying to minimize but do not have a clue how to do it.

AudioPostExpert · Jul 28, 2015

TheNoob said:
Haha! I tried my best!

Really, that's your best? If comparing two different interiors and an exterior is the best you can do, what's the worst?

TheNoob said:
Yes, that's my fridge!

I specifically mentioned turning off all electrical devices in my previous post. Maybe I should also have specifically mentioned other people talking in the background too?

TheNoob said:
but the main noise is coming from my equipment.

Well then, you've got a lot better ears than me! I can't tell exactly how much of the noise is room tone, how much is other background noise and how much is your equipment. If I had to guess, I'd say the background noise+tone appears to be more of the "main" noise rather than your equipment.

If you want to test something then you need to make all the other factors you're not testing identical otherwise you've no idea exactly what it is you are testing. Therefore, have the mic setup at a precise (unchanging) position from the person speaking, in and identical (preferably silent) room and change nothing between tests except your connection methods. Ideally use a recording for the test as a person cannot reproduce exactly the same speech every time. Shouldn't be hard to do and would be far more worthy of calling it "your best"!

G

TheNoob · Jul 28, 2015

AudioPostExpert said:
Really, that's your best? If comparing two different interiors and an exterior is the best you can do, what's the worst?

If you want I can show you, but it might not be pleasant to hear.

AudioPostExpert said:
Well then, you've got a lot better ears than me!

Thanks, I guess?

AudioPostExpert said:
I can't tell exactly how much of the noise is room tone, how much is other background noise and how much is your equipment. If I had to guess, I'd say the background noise+tone appears to be more of the "main" noise rather than your equipment.

These recordings weren't ideal but the best that I could do at the moment as I said earlier. And as I said before I posted the recordings. I will do another test and upload them soon. It is not easy to create an ideal environment where I live. I hope you understand that.

soundslikejoe · Jul 28, 2015

Take the setup from example one and bury yourself in a closet far from everyone else. Take extra pillows with you.... stuff some clothing into the crack at bottom of the door... make a poor kids iso booth.... then listen to your recording. Less noise?

AudioPostExpert · Jul 28, 2015

TheNoob said:
If you want I can show you, but it might not be pleasant to hear.

It won't make any difference, there's already too much and too variable background noise to make it impossible to detect any difference between your connection methods. Having even more background noise can't make it any more impossible!

TheNoob said:
It is not easy to create an ideal environment where I live. I hope you understand that.

And I hope you understand that the different connection methods you are testing should result in fairly subtle differences in audio quality, far more subtle than different rooms or relative mic positions! Regardless of where you live, unless you can get reasonably close to ideal conditions, then any differences you hear will likely have little or nothing to do with what you're testing!

In theory the best connection should be the digital one, however, unless you're using a converter/attenuator you have a level mis-match between your Mix-PreD and your Marantz. This mis-match could cause some quite serious problems, some subtle ones or none at all, depending on the circuitry of the S/PDIF input on your Marantz.

G

Alcove Audio · Jul 28, 2015

Okay, I'll just condense and simplify.

There is ALWAYS noise everywhere - except, perhaps, in an anechoic chamber. What you must do is "control" the noise. This is extremely difficult outdoors. It is easier to control noise indoors, but most low/no/mini/micro budget indie filmmakers never bother.

The "secret" to quality production sound is skills/technique and knowledge.

You will need to properly gain-stage your audio recording system. Improper gain-staging will increase the self-noise of the equipment being used.

The mic(s) must be as close to the sound source as possible and properly aimed - in the case of actors the mic should be in front of and above the talent (out of the frame) and aimed at the notch at the base of the throat.

Do everything possible to control noise on the set.

As stated previously this is quite hard to do outdoors, so the proximity and the aiming of the mic becomes even more important.

Indoors you have more options to control the sonic environment. Most indoor indie "sets" are residences rather than an actual film set. Unplug from the electrical outlet every electronic device that you can. Why unplug from the wall? When turned off most modern electronic devices (computers, TVs, cable boxes, clock-radios, microwave ovens, etc.), are actually in a standby mode, and in standby mode these devices still emit electric impulses into the environment. (Here's a "trick" that many low/no/mini/micro budget indie PSM/Boom-Ops use; put your car keys in the refrigerator so you remember to plug it back in when the shoot is complete.) Oh, all wireless devices - phones, pads, games, etc. - should also be turned off as they (obviously) emit all kinds of EM frequencies, preferably the batteries removed for the reasons previously stated.

To minimize the hollow, echoey, roomy sound prevalent in most indie films use lots of carpeting, sound blankets, heavy plush furniture and anything else that will absorb sound and reduce acoustic "bounce." You should also stay as far back from walls as possible, and try not to shoot directly at a flat wall to reduce standing waves.

After all of this there will still be noise. As APE mentioned the more advanced (i.e. expensive) the NR system being used the better the results. Also keep in mind in a budgeted professional audio post all that's left of the production sound are the lines of dialog; all of the spaces between are replaced with room tone.

I would suggest that you read a number of books about production sound and audio post, and spend some time at FilmSound.org or JWSoundGroup.net.

TheNoob · Jul 28, 2015

AudioPostExpert said:
It won't make any difference, there's already too much and too variable background noise to make it impossible to detect any difference between your connection methods. Having even more background noise can't make it any more impossible!

I'm pretty creative. I'm sure I can figure something out.

AudioPostExpert said:
And I hope you understand that the different connection methods you are testing should result in fairly subtle differences in audio quality, far more subtle than different rooms or relative mic positions! Regardless of where you live, unless you can get reasonably close to ideal conditions, then any differences you hear will likely have little or nothing to do with what you're testing!

The issue was the noise problem as I stated in my original post. The different connections were just done for troubleshooting. But you said that's pointless due to ambient sounds. And I understand that. Although I should mention both test 1 and test 2 were taken in the same exact place, only test 3 was taken outside. I was unable to do test 3 in that area.

AudioPostExpert said:
In theory the best connection should be the digital one, however, unless you're using a converter/attenuator you have a level mis-match between your Mix-PreD and your Marantz. This mis-match could cause some quite serious problems, some subtle ones or none at all, depending on the circuitry of the S/PDIF input on your Marantz.

MixPre-D outputs S/PDIF with an RCA adaptor. And on top of that. I've read that it is fine to use the cable I am currently using.

https://www.gearslutz.com/board/rem...241-marantz-pmd661-aes3-spdif-conversion.html

Alcove Audio said:
Okay, I'll just condense and simplify.

There is ALWAYS noise everywhere - except, perhaps, in an anechoic chamber. What you must do is "control" the noise. This is extremely difficult outdoors. It is easier to control noise indoors, but most low/no/mini/micro budget indie filmmakers never bother.

The "secret" to quality production sound is skills/technique and knowledge.

You will need to properly gain-stage your audio recording system. Improper gain-staging will increase the self-noise of the equipment being used.

The mic(s) must be as close to the sound source as possible and properly aimed - in the case of actors the mic should be in front of and above the talent (out of the frame) and aimed at the notch at the base of the throat.

Do everything possible to control noise on the set.

As stated previously this is quite hard to do outdoors, so the proximity and the aiming of the mic becomes even more important.

Indoors you have more options to control the sonic environment. Most indoor indie "sets" are residences rather than an actual film set. Unplug from the electrical outlet every electronic device that you can. Why unplug from the wall? When turned off most modern electronic devices (computers, TVs, cable boxes, clock-radios, microwave ovens, etc.), are actually in a standby mode, and in standby mode these devices still emit electric impulses into the environment. (Here's a "trick" that many low/no/mini/micro budget indie PSM/Boom-Ops use; put your car keys in the refrigerator so you remember to plug it back in when the shoot is complete.) Oh, all wireless devices - phones, pads, games, etc. - should also be turned off as they (obviously) emit all kinds of EM frequencies, preferably the batteries removed for the reasons previously stated.

To minimize the hollow, echoey, roomy sound prevalent in most indie films use lots of carpeting, sound blankets, heavy plush furniture and anything else that will absorb sound and reduce acoustic "bounce." You should also stay as far back from walls as possible, and try not to shoot directly at a flat wall to reduce standing waves.

After all of this there will still be noise. As APE mentioned the more advanced (i.e. expensive) the NR system being used the better the results. Also keep in mind in a budgeted professional audio post all that's left of the production sound are the lines of dialog; all of the spaces between are replaced with room tone.

I would suggest that you read a number of books about production sound and audio post, and spend some time at FilmSound.org or JWSoundGroup.net.

AH! Very informative!! Thank you. And I might have messaged you years ago in PM. I do not think you remember. But thanks for the help then, and now! (took me years to buy audio equipment)

EDIT: What books do you recommend?

soundslikejoe said:
Take the setup from example one and bury yourself in a closet far from everyone else. Take extra pillows with you.... stuff some clothing into the crack at bottom of the door... make a poor kids iso booth.... then listen to your recording. Less noise?

My closet's way too tiny it might not sound good inside there! But if I ever fail, I will bury myself in my closet and die with my audio equipment.

Alcove Audio · Jul 28, 2015

TheNoob said:
What books do you recommend?

Here's a place to start:

Dialog Editing - John Purcell
The Foley Grail - Vanessa Ament
The Sound Effects Bible - Ric Viers
The Location Sound Bible - Ric Viers
Sound Design - David Sonnenschein
Practical Art of Motion Picture Sound - David Yewdall
Audio-Vision - Michel Chion
Audio Postproduction for Film and Video - Jay Rose

And don't forget to spend time at FilmSound.org and JWSoundGroup.net.