weird modulation(?) on audio recording - help!

[rayw]

Yeah, this is the 1inch stuff. Shaped. Does the trick and within my little budget...

So going back over the thread, is it safe to say that it's not the way the interfaces are talking to Audacity or my macbook, rather it's artefacting from microphone positioning? Just trying to whittle the casues down. As I say, this never occured with the NTG1 and I was on cans for monitoring then too.

And I need to know if I tell the guy who's just sent me a returns form for the NT1 that it's a problem between microphone and, well actually, it's not, is it? It's a problem before the mic and computer!

It is just as simple as keeping the monitor level really low? How can you hear if you click and pop, though?

I'll try for a test record later on today.

[Trebor]

... Just trying to whittle the casues down. As I say, this never occured with the NTG1 and I was on cans for monitoring then too.

One microphone characteristic I forgot to mention is the sensitivity-pattern.
Using a narrow sensitivity-pattern, (say super-cardioid "shotgun", NTG1), will mean less unwanted sound reaches the mic,
e.g. sound reflected from the walls of the booth.
The downside is less latitude for head movement off-axis than with a wider sensitivity-pattern, (e.g. cardioid, NT1).

It is just as simple as keeping the monitor level really low? How can you hear if you click and pop, though?

earbuds & ear-defenders combo is a cheap no-bleed solution.

[rayw]

..so it might be sound leaking from the cans hitting the mic AND walls and bouncing into the mic? I see. The NTG1 seems to put a lot more noise on my recordings with the H5, a 6/6/6 noise reduction was always necessary with those recordings but they all passed ACX check. These mics even in the H5 seem a lot quieter.

Funny though, the Sennies always felt very tight on my big head. didn't think much could get out.

I'll have a go at that later on, thanks for the steer. Fingers crossed!

[rayw]

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).

okay, so.

Here's something weird, I removed the headphone jack during a record, I'm *sure* I can hear a change in the quality of my voice at the 9-second mark upon remoing the jack.

pluginplugout.wav

(1.78 MiB) Downloaded 4 times

now with ACX processing (just for the volume really)

pluginplugoutACX.wav

(1.78 MiB) Downloaded 3 times

IS IT THE ADAPTER?!? that might be crazy talk...

[rayw]

Right, did another test just now, saying a sentence that used the word 'maximize'. One was in the box - foam, walls, etc. One was in the same space but under a duvet.

These are screengrabs of the same word in spectrogram view. Now, I don't really understand how the spectrogram view works, but even I can see that the top one isn't the same as the bottom one.

Screen Shot 2020-05-18 at 23.36.49.png (590.22 KiB) Viewed 46 times

Screen Shot 2020-05-18 at 23.36.56.png (589.66 KiB) Viewed 46 times

Please can someone explain to me what's happening in that top screencap? Because out of the two recordings this one sounded ripple-y and this was the not-under-the duvet one.

Putting all the pieces I have together so far, it's not a good space to use these mics for recording unless under something to break up the shape of the room and stop sound from bouncing straight back into the mic?

And yes, low battery posting.

[Trebor]

Here's something weird, I removed the headphone jack during a record, I'm *sure* I can hear a change in the quality of my voice at the 9-second mark upon remoing the jack.

pluginplugout.wav

I think so too: visibly the spectrum is less craggy after the headphones are unplugged ...

before is green , after is blue

''want to know more about the breeds'', before-after unplugged headphones.gif (94.59 KiB) Viewed 44 times

Resonance produces deep valleys & high peaks on a spectrogram.

[rayw]

Thanks, Trebor.

Well, I just don't know... I'm truly stumped. How can that make any difference?

And to add to that the above spectrograms were without any monitoring at all and plugged into the H5, so the issue exits regardless of monitoring. What else could there be? Cables? I've got a 20ft XLR that came with the mic, it's just running from mic to interface/recorder and is coiled. Should I be doing something with that? Hooking it up out of the way? I'm just looking at troubleshooting everything now. It must be the space...

I saw a post on another board from seven years ago from a guy who had similar artefacts on his recordings. He never posted to that board again, so I dont' know if he solved it.

[Trebor]

Well, I just don't know... I'm truly stumped. How can that make any difference?

If the headphones are on your head (or in the booth) when you did your plugged-unplugged comparison,
the results are consistent with headphone-bleed: sound leaking from the headphones being picked-up by the mic.

It's not full-on feedback-squeal, but it's sufficient to intermittently distort the sound somewhat in certain conditions:
when a syllable has a particular frequency-content above a volume threshold.

[rayw]

If the headphones are on your head (or in the booth) when you did your plugged-unplugged comparison,
the results are consistent with headphone-bleed: sound leaking from the headphones being picked-up by the mic.

It's not full-on feedback-squeal, but it's sufficient to intermittently distort the sound somewhat in certain conditions:
when a syllable has a particular frequency-content above a volume threshold.

I see. And yes they were. But in that example I had ear defenders and buds in, not the HD25s. Thought it was a good seal. And, just because I'm testing, none of the records made since have even had cans in the room yet I still see that rippling on the spectrogram view.

[rayw]

Just did another one with a duvet in a makeshift overhead rack because I thought the height of the space might be something to do with the resonance. Guess I was wrong; I got something that looks like this and that doesn't look right to me.

I mean am I understanding how to read this spectrogram properly? I assume resonance is a repeated vibration and that's what these ripples are, right? Some words are affected and some are not. That's why some bits of this have more waves than others..?

Screen Shot 2020-05-19 at 01.19.13.png (355.21 KiB) Viewed 36 times