Audio Quality - Constructive Criticism Sought

[mightyfelix]

I have just set up my new recording space in my new apartment, and I'd like another pair of ears or two to let me know how it is sounding. Unfortunately, there is an A/C unit just outside my window that I can't really do anything about, but hopefully it's not being picked up too terribly much. Also, my husband was typing in the next room (some people can type surprisingly loudly!), but he won't be home when I make a real recording.

One of these is unprocessed. The other one I treated just as I had been treating every recording I made in my previous recording space.

https://librivox.org/uploads/tests/tyger_test_unprocessed.mp3
https://librivox.org/uploads/tests/tyger_test.mp3

There is a fairly open space just to my left as I'm sitting at the microphone, and I think maybe I need to hang a blanket there to close off that space. I could also play with putting the microphone to the right of my screen, further into the corner, rather than to the left of it. Thoughts? Suggestions? Or does everything sound good, and I should just run with it?

[IainMF]

There is a fairly open space just to my left as I'm sitting at the microphone, and I think maybe I need to hang a blanket there to close off that space. I could also play with putting the microphone to the right of my screen, further into the corner, rather than to the left of it. Thoughts? Suggestions? Or does everything sound good, and I should just run with it?

The recording doesn't sound too bad. The AC noise is not good, but the voice is intelligible, which is the most important thing.

In terms of making improvements, Minimizing the AC noise would be good. If you could hang a blanket in between the microphone and the AC unit without blocking the air flow that would probably cut down on the high-frequency whine.

Do not move further into the corner. Acoustically corners are bad. There will be a build up of low frequencies which will make you recording sound more muddy.

I would also consider putting blankets on nearby hard surfaces, rather than trying to block off the open space. There is some indication in the frequency response that reflections are somewhat of an issue.

What software are you using? If you are using Audacity I could suggest some processing based on your unprocessed recording. Of if you are using other software I can make general recommendations.

[sjmarky]

Listening through headphones I don't detect significant room reverb, so I think your acoustics are OK as is.

In the unprocessed audio the HVAC is audible even through your voice. The background noise is -40db - way too high.

The processed version cleaned-up nicely. The BG level is -70db, so you could actually use less noise reduction. -60 is plenty good. I tried a high-pass filter set at 80Hz, and it reduced the BG noise in the first test by 10db, meaning that your HVAC is generating noise in the low frequencies. I recommend using a high-pass filter on all your audio. You can create your own in Audacity. Go to Effect>Graphic EQ. Move all the sliders at 80Hz and below to minimum. This removes low-frequency noise below your voice. It wasn't enough alone to get your audio to pass, but it reduces the amount of noise reduction needed. So do the high-pass first, then noise reduction.

[mightyfelix]

There is a fairly open space just to my left as I'm sitting at the microphone, and I think maybe I need to hang a blanket there to close off that space. I could also play with putting the microphone to the right of my screen, further into the corner, rather than to the left of it. Thoughts? Suggestions? Or does everything sound good, and I should just run with it?

The recording doesn't sound too bad. The AC noise is not good, but the voice is intelligible, which is the most important thing.

In terms of making improvements, Minimizing the AC noise would be good. If you could hang a blanket in between the microphone and the AC unit without blocking the air flow that would probably cut down on the high-frequency whine.

Do not move further into the corner. Acoustically corners are bad. There will be a build up of low frequencies which will make you recording sound more muddy.

I would also consider putting blankets on nearby hard surfaces, rather than trying to block off the open space. There is some indication in the frequency response that reflections are somewhat of an issue.

What software are you using? If you are using Audacity I could suggest some processing based on your unprocessed recording. Of if you are using other software I can make general recommendations.

Thanks! I have almost all of the hard surfaces nearby already covered. The blanket I am thinking of hanging would block off the only one remaining, as well as the open space between me and the AC unit outside the window. So it might even muffle that a bit. In fact, I can't think of a good reason not to hang that blanket, so I think I will. The floor is also a hard surface, whereas it was carpeted in my last place. But I'm not sure it's worthwhile to get a rug to put down. And I do like the fact that my roll-ey chair actually rolls here!

I am using Audacity, yes.

[mightyfelix]

Listening through headphones I don't detect significant room reverb, so I think your acoustics are OK as is.

In the unprocessed audio the HVAC is audible even through your voice. The background noise is -40db - way too high.

The processed version cleaned-up nicely. The BG level is -70db, so you could actually use less noise reduction. -60 is plenty good. I tried a high-pass filter set at 80Hz, and it reduced the BG noise in the first test by 10db, meaning that your HVAC is generating noise in the low frequencies. I recommend using a high-pass filter on all your audio. You can create your own in Audacity. Go to Effect>Graphic EQ. Move all the sliders at 80Hz and below to minimum. This removes low-frequency noise below your voice. It wasn't enough alone to get your audio to pass, but it reduces the amount of noise reduction needed. So do the high-pass first, then noise reduction.

Hmm. I've been trying the high-pass filter as you said with less noise reduction, but it doesn't seem to be doing enough. I can still hear a whine left over, which makes me think that a second round of noise reduction is still necessary. So I'm not sure it's worth adding an extra step. I'm still open to suggestions, though!

My current process:

Two rounds of noise reduction. (I do this before editing because it drives me crazy to hear that background hiss while editing.)
Edit out mistakes.
Macro:
-Filter Curve
-RMS normalize
-Limiter
-Amplify -3 (because for some reason the limiter puts it too high. Maybe my settings are wrong for that one?)
-De-Clicker (Yes, I de-click my entire recording, even though everyone tells you not to. It takes forever, but it gives me good results, while I go make a sandwich.)

[TriciaG]

-Amplify -3 (because for some reason the limiter puts it too high. Maybe my settings are wrong for that one?)

Do you have the last option, "Apply Make-up Gain" set to Yes? Try changing it to No.

[mightyfelix]

-Amplify -3 (because for some reason the limiter puts it too high. Maybe my settings are wrong for that one?)

Do you have the last option, "Apply Make-up Gain" set to Yes? Try changing it to No.

It's already on No.

Settings for the Limiter are:
Soft Limit
0.00
0.00
-3.50
10.00

I should maybe also mention that I don't have a very clear grasp of what all of the things in my macro actually do. I read some advice somewhere that said "try this," so I tried it, liked it, kept it.

[iBeScotty]

This is a tough situation for recording and probably not uncommon. Very few spaces are ideal both in terms of sound isolation and acoustics. The biggest issue here is the noise and that is what I'd focus on first. Noise reduction in post can help but often times leaves a noticeable distortion of the voice as in this case sounding like speaking into a tin can.

If you cannot control the AC and you need to use this room there may be a couple of things that may help reducing what gets into the mic. First, I definitely would experiment with mic placement. Try placing the mic, assuming a cardioid pattern, with the rear facing that wall and as far away as possible. Speaking of mics, dynamic ones generally are better than condensers at rejecting the off axis sound/noise so if you have access to one that is probably what I'd use. If you end up in a position with back against wall then that is where I would focus the acoustic absorption because those reflections would be strongest into the mic. Also broadband absorption is best as just a blanket will only be effectiove at high frequencies and voices are strongest in the 100-500 Hz range, not to mention the outside noise making into the room through the walls and bouncing around is likely in the lower range. I made some 4 inch thick absorbers that I place with a 1 to 4 inch gap to the wall and I feel these are not thick enough.

Lastly, speaking close to the mic will up the "signal to noise" ratio so I would get as close as possible, at the very least within around 7 inches or so.

Your sound is not dry but it is not bad or distracting (not like my bad, boxy sound from recording in a closet--though it is super well isolated). I know professional VO people need a dry sound but that is only to give the audio engineer flexibility in processing. Since we are providing the final product I think some reverb is totally okay and can be nice.

Hope this helps and good luck!

~scotty