Audio speed

Hi,

I’m running 10.12.16 and Audacity 2.1.3, I believe installed from the .dmg installer.

When I first start up my Mac, everything is swell with Audacity. At some point – I have not been able to identify any instigating event – any recording from microphones is sped up/made higher (both). I can get them back to normal by adjusting the speed down by 5-6%. The project rate is not changed; it is at 44100 before and after. When I restart my machine, it goes back to normal for a spell, and then eventually changes again.

I have attempted to search for prior references to this but wasn’t 100% sure what to search for, so if I missed a prior discussion of it, please accept my apologies.

In case it matters, I’m using an Onyx 820i as my microphone interface, going via an adapter from FireWire to Lightning or whatever the plug is called on the current Mac Minis.

Thanks in advance for any help!

Bill Childs
sparetherock.com

FireWire to Lightning

I thought so. They changed it. My Mini has one of each.

any recording from microphones is sped up/made higher (both).

That means the machine recording slows. They work upside down.

So why would a Mac Mini slow to the point it starts skipping bits or in some other way recording a short show?

I have not been able to identify any instigating event

It may be a time event. Newer Macs time themselves and if it’s really quiet and there’s nothing exciting happening, they start nodding off. They go into an efficiency mode. Can’t waste those clock cycles.

App Nap
Fourth little blue tick down on the left.

http://manual.audacityteam.org/man/faq_recording_troubleshooting.html#mac_crackle

Oddly, the worst part of this problem isn’t the damaged audio. It’s that you can’t reproduce the problem. You know how this works. You take your car in for a noise and it doesn’t do it while it’s there, but the instant you get it home…

Start a recording with the microphone listening to a radio or something identifiable and then just let it go for an hour or so. Don’t touch the computer. Did it change? Mark the time. Only you know what the experimental time should be. Doesn’t have to be an hour.

Does it come back to normal if you close and restart Audacity?

Just because I’m obsessive: while it’s broken, do headphones plugged into the mixer sound OK?

Do whatever you need to do to reset back to normal and make another similar recording. Did it crack at the same time?

Koz

Koz,

Thanks for the response! Here are my notes:

Start a recording with the microphone listening to a radio or something identifiable and then just let it go for an hour or so. Don’t touch the computer. Did it change? Mark the time. Only you know what the experimental time should be. Doesn’t have to be an hour.

I think this suggests that I was not clear in my first post, so let me describe what I’m doing better. I do a radio show (syndicated and pre-recorded). I record each voiceover track consecutively as separate tracks; they total perhaps 8 minutes per hour-long show. To date anyway, it has never sped up during an individual track. Last week for example, I think the first four or five segments were normal and the remaining two or three were fast and high pitched.

Does it come back to normal if you close and restart Audacity?

No. Only if I restart the entire machine.

Just because I’m obsessive: while it’s broken, do headphones plugged into the mixer sound OK?

Headphones plugged into the mixer sound OK.

Do whatever you need to do to reset back to normal and make another similar recording. Did it crack at the same time?

Because it doesn’t change pitch/speed during a particular track–or at least it has not as yet–I don’t think I can do this experiment.

Thanks so much again for any advice! I can largely work around this, by restarting the computer before recording and force fixing any tracks that are weird. But it sure would be nice for it to stop happening!

Bill

To date anyway, it has never sped up during an individual track. Last week for example, I think the first four or five segments were normal and the remaining two or three were fast and high pitched.

OK. That’s scary. I think it’s safe you would not have found that in a casual FAQ search.

That’s an Apple conspiracy. Obviously, after the fourth segment, you need to buy a new Mac.

Nothing leaps out at me. I would be running Activity Monitor during these episodes.


You may find one of your apps is slowly filling up your machine as you work. Do you have any Adobe apps? Adobe has a “gentle licensing reminder” that slowly strangles your machine. See which app floats to the top. Firefox browser can slowly get bigger and bigger as you use it. Of my two machines, one has Firefox reigning itself in at an appropriate memory usage, the other goes nuts.

Koz

I hope you’re aware none of the Mackie products support Sierra and maybe never will?

These are solid products, but driver wise, Mackie hasn’t been too generous. Just a few years of driver support is too short for a professional product imho.

Yes, I’m aware that it doesn’t formally support Sierra, but it has worked without these issues (on Sierra) for a long time. It is with the most recent update or two of Audacity that the speed issue has surfaced.

It is with the most recent update or two of Audacity that the speed issue has surfaced.

It used to be possible to roll Audacity back to an earlier version. Unfortunately, I think those were on Gale’s machines and Gale reached “end of life.”

This is also Holiday/Vacation time for several elves, so we may just get to wait.

Koz

Actually, I remember now that at least this Mackie interface doesn’t require a driver – it works through OS X’s Core Audio infrastructure. So I don’t have any drivers installed, so I’m pretty sure it’s not a driver issue. My old interface (which was not a Mackie) did require drivers and frequently stopped working with OS X updates.

Do you remember which Audacity version did work?

I’m going through the list of pathways and services trying to think of a trap.

What’s the show? Singing? Playing instruments? Gregorian chants? If you are not one of the principal performers, you can listen to the computer playback. Set Audacity > Preferences > Recording: [X] Playthrough (both if you have two). Make sure you’re set to play to the computer’s headphone connection, not the interface. This won’t work if you’re overdubbing. Are you? De-select Overdubbing in that panel.

When you listen, the show will be delayed, possibly significantly, but that means the show has been inside Audacity and come back out again. It should be impossible to make a bad recording and still hear good audio. That’s how I used to confirm live recordings from performers at work. The delay was very significant, but if I crunched into my headphones hard enough, I could hear a perfect, clear voice—just late from the live one. Obviously, if you’re personally one of the performers, that’s not going to work. The delay will make you nuts.

Koz

The show is, alas, me talking. (Well, it’s a music show, but all of my recordings are me front- or back-selling songs.)

I don’t remember which version was consistently working correctly. I did a show last night and it worked perfectly for the entire show. (This is a super frustrating issue!)

How did the Activity Monitor display come out? Memory is a good snapshot of what’s going on in the machine during performance.

Macs have a memory checker. I need to look that one up.

Do you run any other apps while you’re performing? I probably wouldn’t.

Did you bottom feed the machine? Is it the smallest, most underpowered, “affordable” machine you could get? Macs do OK shuffling apps in tiny memory, but sooner or later they all have to start swapping to hard drive and then performance goes into the gutter. Do you have a spinning metal hard drive? My last four machines all had Solid State Drives and maxed out memory and I’ve never had performance problems with any of them.

Past that I got nothing. The programmers have a thing called “Moonphase Error.” Sometimes when the second monthly moon is in the fifth waxing quarter on Thursday, the program will crash. Those make everyone nuts.

Troubleshooting does give us some hints:

Making it better or worse is equally valuable. Can you force it to be worse?

Change things in sequence and pay strict attention to what happens, even things that seemingly have nothing to do with your job.

Run diagnostics (see Activity Monitor).

Change half the system. This one can start to get expensive. The problem will in all probability follow only one of the two halves. Borrow or rent a second computer.

Koz

https://www.cnet.com/how-to/how-to-test-the-ram-on-your-mac/

I don’t think it gets diagnostics from the Apple servers, as it says. That wouldn’t be useful. I think it’s getting the service from the emergency diagnostics portion of your drive. I did this recently and it gives you an option of one fast pass, or repeated passes. Select repeated. They warn you it might take a while. Go make tea.

Make sure your computer’s vents are unrestricted. The machine is going to get warm with stress tests.

Koz

Do you get the Chong each time you start?

Koz

Sorry, I know I should go Mac OS, but it seems locked. I have a a problem with audio codec. Cupertino has been open from its lossless audio codec (ALAC), ALAC can reduce the amount of memory required for audio files by up to 50% without losing the original recorded fidelity, which is not as lossy as MP3 and AAC, but when I converted my FLAC to ALAC, I failed for known reason, I downloaded a program (http://www.videoconverterfactory.com/tips/flac-to-alac.html) from a giveaway site,but it called me to set some parameters, such as framerate, I don’t know about these parameters, I have checked http://manual.audacityteam.org/man/tutorial_exporting_to_ituns.html, till no idea anyone can help me? please