weird modulation(?) on audio recording - help!
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This forum is for Audacity on macOS 10.4 and later.Please state which version of macOS you are using,
and the exact three-section version number of Audacity from "Audacity menu > About Audacity".
Audacity 1.2.x and 1.3.x are obsolete and no longer supported. If you still have those versions, please upgrade at https://www.audacityteam.org/download/.
The old forums for those versions are now closed, but you can still read the archives of the 1.2.x and 1.3.x forums.
Re: weird modulation(?) on audio recording - please help!
FWIW, deleted the double post in the Audiobook forum. New here and don't want to be a pain.
Re: weird modulation(?) on audio recording - please help!
okay, so do I set the interface to 44.1/24 and have my project set at 44.1/32?steve wrote: ↑Sun May 17, 2020 5:10 pm
Normally Audacity should be set up to record as 32-bit float. See: https://manual.audacityteam.org/man/qua ... ences.html
What is the difference?
Re: weird modulation(?) on audio recording - please help!
Yes, that's fine.
The main benefit of working in 32-bit float is that it can handle signals over 0 dB, so, for example, if you apply an effect or mix some tracks and the result goes over 0 dB, then you can simply Normalize, or amplify by a negative amount to bring the audio back into range. On the other hand, with 24-bit (or any other integer format), if the process or mix went over 0 dB, then the audio would be permanently damaged because integer formats can't go over 0 dB - they simply clip off peaks at 0 dB.
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)
Re: weird modulation(?) on audio recording - please help!
The recording level is a little low, and it could benefit from a sub-bass roll-off filter, but other than that it seems OK to me.
We normally recommend the "Low roll-off for speech" preset in the "Filter Curve" effect, though you may of course create your own curve if you prefer.
How are you listening to your recording? Headphones? Speakers? Make / model?
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)
Re: weird modulation(?) on audio recording - please help!
Thank you for explaining the bit depth thing. I thought the interfaces would be putting out too much signal, if you like, if set to higher output rates, like putting a teaspoon in a firehose stream and that was what was causing the distortion; too many bits for the project bitrate. But if that's not the case, I think I'm overthinking it...
...so did you hear anything *ON* the word "ultimately'? Because I sure do when I'm on cans, as did someone I asked to listen. Does anyone else?
I use my old monitoring headphones, a pair of Sennheisers, the HD25-1. Part of my old broadcast kit, always use them for editing. See that's the thing, I've worked in broadcast for years, shot and edited my own stuff and now dealing with hard-core audio editing (well, it's not even that, currently it seems to be that I'm incapable of plugging a device in and having it work properly)
I apply the low roll-off as part of the ACX mastering procedure. But even after that it's still audible. I've checked with the Sennies, a pair of gaming heaphones and even some iphone headphones and there's something there... And to be honest, I wouldn't know what a different filter curve would do!
The record level IS low, but I find that applying the ACX workflow (I assume the RMS normailsation) bumps that up to peaks of about -6 to -3. And I'm conscious to keep the noise floor below -60; I use the RMS settings for the record monitor level as I've seen elsewhere here to do, I think it's low-level myself as well - but anything higher sounds blown out after applying my macro.
See the thing is, I've been using a Zoom H5 as my interface or recording straight to SD card with a camera mic (NTG1 shotgun, bit noisy so wanted better stuff) and editing that way, I wanted to take a more pro approach and get the right kit; so decent(er) mic, (NT1 and AI1 kit, then the panic buy of the Solo and NT1A) but running BOTH systems into the computer and I get the same distorts and jaggy-sounding recordings, apart from one record last night when I modified the output settings of the interface, as written a few posts above when I thought I'd cracked it, then that distortion on the word 'ultimately' in the clip posted during an edit today...
I just can't understand the issue. I don't even think it's the laptop as, as said, I've used the H5 as an interface with no troubles. Plug and play seems to be not the case.
edit: typo
...so did you hear anything *ON* the word "ultimately'? Because I sure do when I'm on cans, as did someone I asked to listen. Does anyone else?
I use my old monitoring headphones, a pair of Sennheisers, the HD25-1. Part of my old broadcast kit, always use them for editing. See that's the thing, I've worked in broadcast for years, shot and edited my own stuff and now dealing with hard-core audio editing (well, it's not even that, currently it seems to be that I'm incapable of plugging a device in and having it work properly)
I apply the low roll-off as part of the ACX mastering procedure. But even after that it's still audible. I've checked with the Sennies, a pair of gaming heaphones and even some iphone headphones and there's something there... And to be honest, I wouldn't know what a different filter curve would do!
The record level IS low, but I find that applying the ACX workflow (I assume the RMS normailsation) bumps that up to peaks of about -6 to -3. And I'm conscious to keep the noise floor below -60; I use the RMS settings for the record monitor level as I've seen elsewhere here to do, I think it's low-level myself as well - but anything higher sounds blown out after applying my macro.
See the thing is, I've been using a Zoom H5 as my interface or recording straight to SD card with a camera mic (NTG1 shotgun, bit noisy so wanted better stuff) and editing that way, I wanted to take a more pro approach and get the right kit; so decent(er) mic, (NT1 and AI1 kit, then the panic buy of the Solo and NT1A) but running BOTH systems into the computer and I get the same distorts and jaggy-sounding recordings, apart from one record last night when I modified the output settings of the interface, as written a few posts above when I thought I'd cracked it, then that distortion on the word 'ultimately' in the clip posted during an edit today...
I just can't understand the issue. I don't even think it's the laptop as, as said, I've used the H5 as an interface with no troubles. Plug and play seems to be not the case.
edit: typo
Re: weird modulation(?) on audio recording - please help!
Now I get it: When the volume of your voice goes above a threshold there is a some harsh resonance.
Possible causes of resonance ...
Headphone leakage, (as an experiment try speaking at different volumes in the booth without headphones).
Reflected sound within the booth, (try moving the mic closer to the centre of the booth, or thicker insulation).
Re: weird modulation(?) on audio recording - please help!
The booth is a coat cupbboard I have treated with acoustic foam and blankets, not ideal but much more snug than before and quiet enough. The thing I don't get it that this resonance happens on with different mics and interfaces and mic positions...
And recording witht eh H% doesn't seem to produce the same essfect. That makes me thingk there's trouble with the computer, as I say two seperate interfces can't be duff.
Any Mac users out there who can tell me if it's a good idea to trash my sound preferences, maybe? I'm not going to do anytihing like that 'til this record's donr though.
And recording witht eh H% doesn't seem to produce the same essfect. That makes me thingk there's trouble with the computer, as I say two seperate interfces can't be duff.
Any Mac users out there who can tell me if it's a good idea to trash my sound preferences, maybe? I'm not going to do anytihing like that 'til this record's donr though.
Re: weird modulation(?) on audio recording - please help!
The resonance effect will be dependent on ...
The frequency-response & sensitivity of the microphone.
The position of the mic in the booth.
How big the booth is.
How reflective the walls of the booth are.
How high you have the gain on the interface, (i.e. we're back to mic-sensitivity).
How loud you are speaking.
Unless the source is sound leaking from your headphones, the cure is an acoustically-dead booth.
Re: weird modulation(?) on audio recording - please help!
Well, I was just doing another record and I noticed this resonance pop up again....
I won't post it here because it's the same as in earlier samples. It has to be the mic position I guess, as I wasn't using a new (Rode/Scarlett) interface, the idea was to keep things as they were and just change the mic. I'm using TWO Rode mics, NT1 and NT1a and getting the same thing. I'm unsure as to how frequency response and sensitivity will affect resonance; I'm just used to plugging them in and filming or talking.
Current setup that I heard this resonance on was the NT1 with a Zoom H5 acting as an audio interface. Record level on the H5 was set to 5, as I've said in other posts, that's about the best the H5 offers as a preamp without being too noisy in my earlier set up. I was using an NTG1 and noticed lots of hiss in earlier experiments that I thought would be distracting to a finished audiobook, so 'get better mic and interface' was the thought that caused all this in the first place.
Anyway...
Mic was in its usual position; facing a rack of (covered) coats with a wall of acoustic foam behind me and the mic. A upwards-mounted Rode boom pole (i.e., base of pole is a few feet above my head) holds the microphone and the boom pole is held in place by tension against the foam on that part of the wall and the rail the coats are hung onto. I'm presenting to the mic centrally, and the mic is held in a SM1 mount.
I do have a boom arm that I'm intending to use, but I have yet to figure out how to mount it in there; the boom pole and shock mount seemed an acceptable compromise.
I'm approximately 5-6 inches away from mic (three inches from popshield) and headphone monitoring isn't too loud (I don't think). I'm not shouting, indeed this current recording sounded a bit flat and depressed(!), but I'm projecting a touch as I read, as one would. Peaking about -12 to -10 on the Zoom. When setting record levels direct to Audacity, I've been using a guide I saw here somewhere about setting the record monitoring to RMS and keeping the red line under -60 (including the darker bouncing bit), so that's where I've been settimg record level on the interfaces.
This current record was to SD card and import into Audacity, so it HAS to be how I'm dealing with the mic, I guess.
The dimensions of the room are 4ft x 3ft x 8ft (it's tall but there's foam all the way up and over the ceiling. There's occasional bumps or clatters from the next door flat, but nothing at all that would distract, occasional noise from a water pipe. But I notice and stop when that happens)
But the thing is I"ve noticed this ONLY on the NT1 and NT1A, *never* using the NTG1.
Should I face it the other way, towards the foam?
Sorry for the wall of text, but when I'm troubleshooting, more info is better than less. But still, sorry.
edit: dimensions
I won't post it here because it's the same as in earlier samples. It has to be the mic position I guess, as I wasn't using a new (Rode/Scarlett) interface, the idea was to keep things as they were and just change the mic. I'm using TWO Rode mics, NT1 and NT1a and getting the same thing. I'm unsure as to how frequency response and sensitivity will affect resonance; I'm just used to plugging them in and filming or talking.
Current setup that I heard this resonance on was the NT1 with a Zoom H5 acting as an audio interface. Record level on the H5 was set to 5, as I've said in other posts, that's about the best the H5 offers as a preamp without being too noisy in my earlier set up. I was using an NTG1 and noticed lots of hiss in earlier experiments that I thought would be distracting to a finished audiobook, so 'get better mic and interface' was the thought that caused all this in the first place.
Anyway...
Mic was in its usual position; facing a rack of (covered) coats with a wall of acoustic foam behind me and the mic. A upwards-mounted Rode boom pole (i.e., base of pole is a few feet above my head) holds the microphone and the boom pole is held in place by tension against the foam on that part of the wall and the rail the coats are hung onto. I'm presenting to the mic centrally, and the mic is held in a SM1 mount.
I do have a boom arm that I'm intending to use, but I have yet to figure out how to mount it in there; the boom pole and shock mount seemed an acceptable compromise.
I'm approximately 5-6 inches away from mic (three inches from popshield) and headphone monitoring isn't too loud (I don't think). I'm not shouting, indeed this current recording sounded a bit flat and depressed(!), but I'm projecting a touch as I read, as one would. Peaking about -12 to -10 on the Zoom. When setting record levels direct to Audacity, I've been using a guide I saw here somewhere about setting the record monitoring to RMS and keeping the red line under -60 (including the darker bouncing bit), so that's where I've been settimg record level on the interfaces.
This current record was to SD card and import into Audacity, so it HAS to be how I'm dealing with the mic, I guess.
The dimensions of the room are 4ft x 3ft x 8ft (it's tall but there's foam all the way up and over the ceiling. There's occasional bumps or clatters from the next door flat, but nothing at all that would distract, occasional noise from a water pipe. But I notice and stop when that happens)
But the thing is I"ve noticed this ONLY on the NT1 and NT1A, *never* using the NTG1.
Should I face it the other way, towards the foam?
Sorry for the wall of text, but when I'm troubleshooting, more info is better than less. But still, sorry.
edit: dimensions
Re: weird modulation(?) on audio recording - please help!
If you try a short experimental recording with headphones unplugged you will be able to tell if headphone-bleed is the source of the problem. During the experiment include recordings where you raise your voice, (the objective is to see if the resonance effect can be deliberately caused).
You haven't specified the thickness if the acoustic foam. The 1" stuff is helpful, but it's not professional standard.
Mike "booth-junkie" DelGaudio was using solid 4" stuff ... https://youtu.be/m1A6mxsmRO4?t=46