Dangit! Running ACX check ruins my Noise Floor!

[kozikowski]

I know it doesn't make any difference whether the microphone is upside down or not, but the instructions are clear this is a directional microphone and the different between front and back volume is expected to be (wait for it) about 20dB.

I can't wait to see if your voice volume drops by 20dB when you speak into the back.

Koz

[sharcmerman]

Sorry for the delay Koz. (mother's day stuff)

Here are those test recording(s)!

sharcmerman test spark front back.wav

(1.45 MiB) Downloaded 2 times

My model Blue Spark doesn't have those switches for some reason, but it does have this "focus control" button on the back which has been pressed in.

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IMG_3063.JPG (584.01 KiB) Viewed 59 times

The only other switch type thing like this is the one on the preamp I mentioned -- the high-z button, but it looks like that effects input 2, which I'm not using as far as I can tell.

[kozikowski]

My model Blue Spark doesn't have those switches for some reason

The newer model Spark SL has the switches.

Your Focus Control is a low-pitch rumble filter when pushed in. It was taken over by the newer straight-line/bent-line switch. Neither makes any difference because step one in Audacity Audiobook Mastering is a low pitch rumble filter. Many home microphones won't pass ACX without that filter in mastering.

We're getting really close to Stump The Band time.

The Hi-Z switch only affects connection #2. The Spark is a Low-Z microphone and connection #1 is good.

The Front/Back thing appears correct. 'Back' is muffled, dull, and low volume. Perfectly normal.

I see you're using the vibration/shock mount to hold up the Spark. Typically those are like rubber bands and if you very gently tap the microphone it should sloppy wiggle at you. The cable on the rear should have a little dip in it so the cable is not tight. I call it the Drip Loop.

Screen Shot 2020-05-10 at 18.35.19.png (51.88 KiB) Viewed 56 times

I can think of two more possibilities.

High ambient noise is a remote possibility but we can test for that. Make up a heavy towel roll or tunnel that will fit over the microphone. It's best if the toweling doesn't touch. Do a normal voice with a second or two background sounds then slide the sound cave over the microphone. Try to hold it steady for a second or two. Stop. You're creating a second sound studio inside your existing larger studio. We're listening for a change of background noise.

Put the towel away.

Last is a desperation method recording. Take off the pop and blast filter (tennis racket). Move the microphone so it's between your nose and ear instead of straight ahead. Position B. And a lot closer. Say one power fist instead of a full Hawaiian Shaka.





You will almost certainly need to turn the Steinberg down. That's actually the goal. Occasional blue wave tips at 50%. Mostly below that. Announce a ten second test.

Koz

[sharcmerman]

Happy Monday Koz,

I've flipped my mic back right side up and ensured there is ample drip loop in the cable plugged into the mic.

I then recorded the towel test, holding a double folded thick towel over the mic:

sharcmerman towel test.wav

(1.9 MiB) Downloaded 3 times

And next the desperation mode recording, first with input gain at 75% and then stopped recording, and followed by turning the input gain all the way down.

sharcmerman desperation gain 75pct.wav

(1.19 MiB) Downloaded 1 time

sharcmerman desperation gain 0pct.wav

(966.99 KiB) Not downloaded yet

Nervous to hear we're almost stumping the band but thank you for continuing to investigate!

[kozikowski]

sharcmerman towel test.wav

I don't understand any of this. When you put the noise-shielding, protective towel on, the noise level went up......*

However, I did get one to work.

I started with the 75% reading, applied normal Audiobook Mastering followed by Noise Reduction of the Beast (6, 6, 6).
It sounds natural and it easily passes ACX conformance.

sharcmerman desperation gain 75pctMasteredAndNR.mp3

(332.45 KiB) Downloaded 1 time

Practical Noise should be quieter than -65dB.

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Drag-select some of the clean background noise. Effect > Noise Reduction > Get Noise Profile. Select the whole track > Effect > Noise Reduction: 6, 6, 6, Reduce > OK.

That may be the way of the future.

Koz

[sharcmerman]

Wow. Ok I'll do some more desperation mode around 75% and see if that continues to pass inspection.

If this works for ACX, that works for me, but because of the nature of some of my other voice work, desperation mode would restrict some other performances. I only worry that the other work I refer to - commercials, characters, etc - might have lower quality than I was aware of before going through this ACX process. In your opinion, should I look into trying out an alternative mic or preamp? And do you have opinions on options for those? I see different people's recommendations all over the internet, but have valued your feedback here.

[kozikowski]

the other work I refer to - commercials, characters, etc

The stress is on ACX Compliance because in general, if you can make it past them, you can do anything else. For example, their specifications are a close cousin to Broadcast Proof of Performance, the quality check your (US) station has to pass before you go on the air.

should I look into trying out an alternative mic or preamp?

There is one easy way out. Get yourself rolling at a commercial sound studio while you're working on your home microphones. Several posters have done that. The only downside is keeping all your book chapters matching. Don't bring a home microphone on-line half-way through a book.

Also regard Ian in Hollywood (the real place not the Dream Factory). He holds the record for the longest forum posting. 39 forum chapters and over a year. All he wanted was read for audiobooks from his apartment just off La Brea. We did get him working and he's a successful performer.

I have no recommendations other than what you have can be made to work. I can usually guess at it, but in your case you have enough conflicting symptoms and conditions that I'm going to step quietly back and watch. Did you offend a sorcerer recently?


One note. If you do opt for another rig, read the complaints, not the recommendations.

Koz

[sharcmerman]

Hello again Koz!

I have been meaning to follow up and thank you again for all of your guidance, but I kept wanting to finish this audiobook submission before giving the all clear.

Today I've submitted all of the chapters, and it's SO CLOSE! All of the full chapters have no issues, but for some reason, the following entries all have RMS issues being too low (and registering differently than when I run my ACX check in Audacity):
"Opening Credits"
"Closing Credits"
"Retail Audio Sample"

It can't be a coincidence that these shorter files are having this issue pop up, especially because, with the exception of the closing credits file, which is just me saying "the end," the other two are literally just trimmed sections from larger chapter files, which have no issues...

Attaching screenshots of the ACX's Audio Analysis page vs my ACX check in Audacity

Screen Shot 2020-06-18 at 5.48.58 PM.png (892.97 KiB) Viewed 29 times

Screen Shot 2020-06-18 at 5.47.24 PM.png (297.99 KiB) Viewed 29 times

Any idea what the issue might be? Can't wrap my head around why the results would be different like this, when all other settings are identical.

[kozikowski]

the other two are literally just trimmed sections from larger chapter files

I think I got it. Each individual thing you submit has to pass ACX Check. It's not a guarantee that each slice from a chapter which passes will also pass. Particularly with RMS (loudness) which is kind of a rolling average. If you have a relatively quiet, expressive, theatrical portion of the reading and decide to make that into its own file, that will almost certainly fail loudness even though the whole chapter passes OK.

If you check the "The End" file by itself does it pass? I'm betting you're going to get the same "off" numbers they did.

Master and check every individual performance or file you submit.


While you were doing that, we changed ACX Check. You can get the new one from here.

https://wiki.audacityteam.org/wiki/Nyqu ... #ACX_Check

It's very different. It has an abbreviated information panel and it's faster.

Koz

[kozikowski]

There's one other possibility. Post the "The End" file exactly as you submitted it.

Scroll down from a forum text window > Attachments > Add Files.

Koz