The No.1 Website for Pro Audio
How to fix modulation in a dialogue track
Old 22nd October 2019
  #1
Here for the gear
 

How to fix modulation in a dialogue track

I recorded audio with two lav's and one boom into a zoom f8. We were in a remote location and i didn't notice any audio problems when monitoring. Now there is very clear 'intermodulation' (I use that term after researching on the internet, it may not be correct). It is intermittent, in that some of the interviews have it, some dont, without changing my set up. I say this because I don't think it was interference from the microphones. I think it happened in the recorder, because I didn't hear it when monitoring.

I am not extremely experienced. I've been trying all kinds of micro delays and stereo set ups to fix it. I'm wondering if anyone could suggest something or someone that could help.

I've attached a sample.

Thank you!
Attached Files

Linden Intermodulated Boom .mp3 (1.77 MB, 773 views)

Old 22nd October 2019
  #2
Gear Nut
 

Quote:
Originally Posted by Zoe View Post
I recorded audio with two lav's and one boom into a zoom f8. We were in a remote location and i didn't notice any audio problems when monitoring. Now there is very clear 'intermodulation' (I use that term after researching on the internet, it may not be correct). It is intermittent, in that some of the interviews have it, some dont, without changing my set up. I say this because I don't think it was interference from the microphones. I think it happened in the recorder, because I didn't hear it when monitoring.

I am not extremely experienced. I've been trying all kinds of micro delays and stereo set ups to fix it. I'm wondering if anyone could suggest something or someone that could help.

I've attached a sample.

Thank you!
Could use more information. Did you use all three mics at the same time on the same subject? Is the sample just the boom mic? What kind of mics were the lavs and the boom? I assume you have isolated tracks of each mic. What do the isolated tracks sound like? The term intermodulation suggests that multiple mics were in play and were interacting with each other. I'll put it into RX7 and see what it looks like, and if it can be improved at all.
On my small computer speakers I'm hearing a subtle warble character to some of the file. Is that what you're talking about?
Old 22nd October 2019
  #3
Here for the gear
 

Hi Bernie, Thank you!

I had all three mic's on the subject. This is the isolated boom. The isolated lav's have that same subtle warble character you heard, that i never heard when recording.
The next short interview done in the same location, with the same gear was fine, no warble, then the warble is back in the following take.
Perhaps intermodulation isn't the right term! i'm not sure what to call it, but i am still trying to somehow reverse it...
Old 22nd October 2019
  #4
Gear Head
 

Hi,
is that track a mix of boom + lav? Does it still happen when you listen to the isolated boom? If you still did not format the SD card, I would first check how that plays directly from the recorder.
Old 22nd October 2019
  #5
Lives for gear
 
GYMusic's Avatar
Sounds like a problem with the file import.
Old 23rd October 2019
  #6
Lives for gear
Or if you were recording as mp3 rather than PCM, with the recorder's stereo encoding.
Old 23rd October 2019
  #7
Here for the gear
 

yes the link i shared is the isolated boom track and it's on both sd cards playing back in the f8. I've imported a couple of times. i recorded poly wav files so all the tracks are iso's.

I've tried various chorus filters, micro delay but can't find a way to make it better.
Old 23rd October 2019
  #8
Gear Addict
 

That a nasty one. Maybe Celemony Capstan can help:
https://www.celemony.com/en/capstan
Old 25th October 2019
  #9
Gear Nut
 

Quote:
Originally Posted by Zoe View Post
Hi Bernie, Thank you!

I had all three mic's on the subject. This is the isolated boom. The isolated lav's have that same subtle warble character you heard, that i never heard when recording.
The next short interview done in the same location, with the same gear was fine, no warble, then the warble is back in the following take.
Perhaps intermodulation isn't the right term! i'm not sure what to call it, but i am still trying to somehow reverse it...

Finally got time to look at the file in RX. I can see the warble in the spectrogram. The only way RX could fix it would be to go around every part of the words with the attenuate brush and smooth the rough edges. it would be a very daunting and time consuming project. Listening again it sounds like a consistent vibration/modulation of the whole vocal spectrum.
Sorry I couldn't help.
Bernie
Old 26th October 2019
  #10
Gear Guru
 
Muser's Avatar
if everything in the same in a recording and then something changes without having changed anything,
then the fact that it's intermittent at least helps narrow down what the cause might be.
cables can be intermittent, solder joints, mechanical properties and connections can also be. bugs also can be.

this might be of some use in providing more ideas for more potential causes.
even though it has an analog recording bias, the causes and effects may well share similar universes.

https://slideplayer.com/slide/4982932/
Old 26th October 2019
  #11
Gear Nut
 

That's quite a challenge.
For a closer look, you'd have to post a snippet of the original wav file, as too much data get lost in conversion to mp3.
Does it sound equally bad if you playback directly from the recorder?
Topic:
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump