Audio recorded from microphone sounds distorted

F

Farknay

New member
Hello,

When I record audio through my microphone, the audio is distorted. I've checked the levels during recording: my interface usually is around -12db for louder parts. The final recorded audio file shows no clipping. If I record guitar or bass through my interface, the sound is clean.

So far, I suspect that :
1. my microphone suffers some internal damage
2. my interface suffers some internal damage
3. my recording technique needs improvement

Here's the hardware, that I have been owning for several years :
- Interface : Alesis IO 26
- Microphone : Rode NT2 (this one : http://www.foxaudioresearch.ca/Rode NT2.htm), used in cardioid pattern.
- Professional grade XLR cables

I know the simplest way would be to try it with another microphone, but I don't have the money, nor the possibility to borrow one.

Any ideas ?
Thanks.
 
Are you recording the guitar and bass through the microphone or plugged directly into the interface?
 
My usual response is to record a simple, non-processed track with something like Audacity, of if you know how, just bounce it un-processed/normalized from your DAW in a non-lossy format (e.g., WAV 24-bit), and put that in a cloud location where it's available for download, like Google Drive, Dropbox, OneDrive, et al. It helps us to hear the distortion and see the file.

Regardless of the level you see in your DAW (and that depends on how your metering is set up), I assume this is a new problem, but the distortion can also be in the output side, if you haven't ruled that (you say DI recording sounds Ok, so probably *not* but, check all the same), like a blown driver in your headphones or the headphone amp in the interface went south. It's also possible (if unlikely) to overdrive the mic, so try the same recording with the PAD engaged and see how that sounds.
 
keith.rogers said:
My usual response is to record a simple, non-processed track with something like Audacity, of if you know how, just bounce it un-processed/normalized from your DAW in a non-lossy format (e.g., WAV 24-bit), and put that in a cloud location where it's available for download, like Google Drive, Dropbox, OneDrive, et al. It helps us to hear the distortion and see the file.

Regardless of the level you see in your DAW (and that depends on how your metering is set up), I assume this is a new problem, but the distortion can also be in the output side, if you haven't ruled that (you say DI recording sounds Ok, so probably *not* but, check all the same), like a blown driver in your headphones or the headphone amp in the interface went south. It's also possible (if unlikely) to overdrive the mic, so try the same recording with the PAD engaged and see how that sounds.
Click to expand...
Ok, I'll try to pick the non processed WAV file recorded by my DAW and put it somewhere (I'm using Cakewalk by bandlab, which stores audio in WAV files)
 
Good move - the various kinds of mic distortion are quite easy to identify. One thing - you said the waveform shows no clipping? In terms of peaks, or in terms of nasty flat tops to waveforms. It's possible to have distortion from over-level but then have that waveform normalised somewhere. If you record the mic at a much lower level - like say, -30dB, does that also sound distorted? It is possible that it could be a mismatch - a few interfaces supply 48V. but struggle with mics that need the full amount of current. Something in the back of my head says the Rodes were current hungry - but my memory could be wrong here. If the Alesis cannot manage the full 48V the mic needs, this could be a pointer?
 
Farknay said:
Here's a link to two audio recordings of the same phrase, one with padding, the other without : https://drive.google.com/drive/folders/1Ijc8pyH92m554A05oSd8yMr-ykdq2ATF?usp=sharing
Click to expand...
I assume you adjusted the gain on the interface for those clips, because the [with] padding one is only 2dB quieter?

The recorded level is quite low, -20dB peak (or -22dB peak).

I don't hear any real distortion, unless that bit of raspiness right at the start is what you are referring to?
 
Ok, I recorded this quickly and I couldn't properly check the levels (my bad), because the mic is in a different room than my interface (I did indeed just engage the padding button without leveling), I'll try to record a better clip.

By the way, while reading some of the answers, something popped in my mind : could it be a faulty cable ?

Note : I added another clip, longer, with better levels I recorded several days ago. It seems more obvious on this clip, than the two previous ones.
 
Last edited:
Nope - a cable will work, or not - it can't introduce distortion - but in this case, even in the short clip, we are struggling to hear any. The level was low, but it normalised up fine?
 
Farknay said:
Ok, I recorded this quickly and I couldn't properly check the levels (my bad), because the mic is in a different room than my interface (I did indeed just engage the padding button without leveling), I'll try to record a better clip.

By the way, while reading some of the answers, something popped in my mind : could it be a faulty cable ?

Note : I added another clip, longer, with better levels I recorded several days ago. It seems more obvious on this clip, than the two previous ones.
Click to expand...
There's a lot of resonance in something there. See attached spectrum plot. (woman-unpadded) I don't know how that's getting in the recording, but I didn't see it in the short clips, and I didn't look at others. The one I did look at was recorded a little hot perhaps.
 

Attachments

  • Screen Shot 2022-06-07 at 1.23.17 PM.png
    Screen Shot 2022-06-07 at 1.23.17 PM.png
    191.2 KB · Views: 6
Farknay said:
Ok, so I should chase those ressonances instead of thinking my microphone is broken, right ?
Click to expand...
Well, *maybe*. That was a very small bit of the entire file, and I'm not really hearing what I would call distortion, resonances or not. Like I said, it does sound a bit "hot" and maybe backing off from the mic, dialing the gain down a little, both might clean it up. But, what's your space like, and can you still get a good recording if the room is part of what you're tracking?

I didn't see that you said you were using this setup before and never heard this, so I guess the question we didn't ask is, "Is this a new problem?" I.e., do you have an old track in a project recorded before that *doesn't* sound distorted now? Or, is this the first time you've recorded vocals?

Have you let the mic get exposed to excess humidity? That can create problems for condenser mics, so if you have, then pack it in a plastic bag with several of those [fresh] silica gel packs foe a few days.

And, with microphone recording, there are a myriad of things that can go wrong that have to be addressed, not the least of which is isolation of the mic itself. Are you using the popscreen and suspension mount that came with the mic? What is the recording space like? How distant are you from the mic? Etc.
 
The lady sounded er. 'ok' to me as well. I may be well mutton but I CAN hear harmonic distortion when it is present!

This is I suspect another case of wrong terminology, we have been here before (the 'echo' thing?) Myself and all the other technical audio people on the forum will interpret "distortion" to mean harmonic distortion i.e. a gross non-linearity somewhere in the audio path.

Bad, 'honky' acoustics is something entirely different.

Dave.
 
To answer some of your questions :

I've been using this setup for about one year now. I bought the gear several years ago (microphone, cables and interfaces), but never used it more seriously until last year. So, yes, I'm far from being completely at ease with recording, hearing what I should hear and not hear. I feel I made some progress over the last months and this is when I started to notice this annoying sound in the differents vocal recordings I made. I called it distortion, because this how it feels to me. When adding compression it gets worse, like you've added too much saturation, but not a nice one.

About the microphone, I bought it many years ago (I don't think it's sold anymore, it was like 15 years ago), on another continent. And the microphone travelled across the globe with me (just once, and not on a boat). I kept it as dry as possible inside its bag with silica gel. I've been using the original shockmount that came with the microphone. The only problem I have is that the rubber bands are nowhere to be found nowadays. One of them is getting slightly loose, so I plan on buying a new shockmount. And yes, I use a popscreen.

About the room where I record, it's been the same room since last year, the bedroom. The acoustic treatment is far from good, I know that well, but up until recently I thought it was fine. This is one of the reasons why I use this mic in cardioid mode, to limit the impact of the room on the recorded sound. And I try to keep my singer close, but not too close to the mic, for the same reason.

Yesterday evening I realised I had another microphone I could use and test with : an AKG D550, a dynamic mic made for recording a drum bass or bass instruments (I did own a bass amplifier at the time I bought this microphone, but since I don't have this amplifier anymore, it has been put aside). So I recorded the same song with both microphones. Unfortunately, not at the same time, but at least during the same session and I 'hooked' the D550 into the Rode Shockmount. I've added two clips to my google drive shared folder : https://drive.google.com/drive/folders/1Ijc8pyH92m554A05oSd8yMr-ykdq2ATF?usp=sharing.

Now I have more homework to do : browse through some of the earlier recordings I made, years ago and listen to them carefully, and add longer clips to google drive.

Thanks for your patience and answers.
 
Last edited:
Well, I have three files now - the Rode, the AKG and the other that has no padding (and is lower level)

They're very hard sounding, but if you had labelled them mic 1 and mic 2 I would not have immediately said - ah, condenser, or ah, dynamic. I can hear nothing I would classify as distortion - just a commonality in the very in your face, hard sound. I would have expected the AKG to be warmer sounding, but it wasn't. If you had said the AKG was the condenser, I could have gone along with that. I deliberately did not analyse or examine the waveform, just listen to the audio on detailed in-ears and a couple of speaker systems.

I don't appear to have anything that deserves the 'distorted' description, but a quick test with EQ can make it a bit tamer. How close was she to the mic, because the breath sounds are pretty powerful. I would imagine the tonal changes to make it sound nicer are just the angle, the placement and the distance, and the room of course, but it's not coming over as a nasty room?

What are you hearing that I am not? Are we using 'distortion' differently?
 
rob aylestone said:
Well, I have three files now - the Rode, the AKG and the other that has no padding (and is lower level)

They're very hard sounding, but if you had labelled them mic 1 and mic 2 I would not have immediately said - ah, condenser, or ah, dynamic. I can hear nothing I would classify as distortion - just a commonality in the very in your face, hard sound. I would have expected the AKG to be warmer sounding, but it wasn't. If you had said the AKG was the condenser, I could have gone along with that. I deliberately did not analyse or examine the waveform, just listen to the audio on detailed in-ears and a couple of speaker systems.

I don't appear to have anything that deserves the 'distorted' description, but a quick test with EQ can make it a bit tamer. How close was she to the mic, because the breath sounds are pretty powerful. I would imagine the tonal changes to make it sound nicer are just the angle, the placement and the distance, and the room of course, but it's not coming over as a nasty room?

What are you hearing that I am not? Are we using 'distortion' differently?
Click to expand...

Are we using 'distortion' differently? => very likely, from the comments I read here, the definition seems precise to experts.

This is the second mention of my recording having that 'hard sound' (technically speaking keith.rogers said it was 'hot', but I suppose it's similar). I'll take that in mind during my next recording session.
 
You must log in or register to reply here.
Back
Top