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MacBook live use


jason.fallon

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Hi all

 

just looking for some advice. I'm using a MacBook to cue sfx from side stage through a radial jpc di box. I keep getting this intermitting pop from it. Tried new cables, di and still there. It's going into my ls9. Any ideas?

 

Cheers

 

j

 

Try an external USB sound card. See if it still does it.

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I believe Macs send the soundcard to sleep at times and then there is a pop when it starts up again. The problem does not happen when using an external soundcard in my experience. The majority of laptops have horrible audio systems and an external soundcard is always sensible. However, a quick google search found this program which may be of some use. I would still reccomend an external interface with proper connections when connecting a laptop to a sound system.
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Hi

 

Thanks for that software. gonna try that now.

 

Cueing off Qlab

 

Cheers

 

J

 

 

There is a tickbox in Qlab which will 'force coreaudio to stay awake' click qlab on menu bar, select preferences and select 'sound.'

 

however I think it defaults as selected already but it's worth checking.

 

+1 for an external card, although I often use a PC DI box from Interspace industries when I need to travel lite. That said it is essentially the same as using a di box, as far as I am aware.

 

Good Luck.

 

NM

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just to let you know that I have had problems in the past with the internal audio on Macbooks and Pros with interference/pops/clicks, eventually traced the problem down to the power supply. The official psu that came with the Macbook caused interference on the audio out but a cheap chinese imitation one I bought didn't !!
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  • 2 weeks later...
There is a tickbox in Qlab which will 'force coreaudio to stay awake' click qlab on menu bar, select preferences and select 'sound.'

 

This feature was put into QLab 1 at my request. On many, if not all, Intel Macs the OS appears to put the sound chip into some kind of power saving mode when it is not being used. To compound the problem the sound chip doesn't seem to suppress power on transients in the D/A converter properly. The result seems to be that you get a thwap sound before and after playing a sound as the converter powers up and down. The problem does not affect the optical out from the machine only the analogue out.

 

This "fore core audio to stay awake" preference is only available in QLab 1. QLab 2 has entirely different internal audio handling always keeps the audio device open for synchronisation reasons so the preference is in effect always on and is therefore redundant.

 

In any case I would highly recommend that anyone that anyone using a Mac in a live environment uses an good quality external audio interface with a balanced output.

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I use my macbook pro (a few years old now) all the time with a stereo mini jack to a mono 1/4 inch jack and have never heard any problems. I do leave it plugged in all the time and just run itunes (with playlist) and sometimes run spotify. I don't run it from a DI because I am always at FOH position and run it straight into the mixer as insert to a channel. Just to see how mine hasn't had any problems and also a couple of my friends own the white macbook and haven't had any issues.

 

You can maybe leave another application running in the background to stop it from "sleeping" the audio. Although I haven't noticed it when I am running it internally from the macbook but I do see on my imac which I use a external "x-dac" running from the optical output. The x-dac includes indicator lights which light up when processing the audio and it does show that after a while the Imac stops sending audio. You can also look at the options of "audio midi setup" and messing about there to see if there are any options to check.

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  • 7 years later...

Time to revive an old thread...

 

I'm using a mac mini with a behringer FCA610 soundcard, with playback from quicktime. It would appear that core audio is going to sleep and turning off the soundcard, causing a couple of pops and crackles when it turns back on.

 

Is there a known good way of stopping this behaviour, other than switching to QLAB?

 

EDIT: adding software in use

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Time to revive an old thread...

 

I'm using a mac mini with a behringer FCA610 soundcard, with playback from quicktime. It would appear that core audio is going to sleep and turning off the soundcard, causing a couple of pops and crackles when it turns back on.

 

Is there a known good way of stopping this behaviour, other than switching to QLAB?

 

EDIT: adding software in use

 

How are you determining that it is core audio going to sleep?

 

Under system prefs have you set the energy saver controls to eliminate going to sleep?

 

Mac

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Thanks for the response Mac.

 

My googling identified it as a core audio issue, as on the original firmwarre you could see the blue USB light on the sound card turn off, after a few seconds, meaning the computer has sent the core audio to sleep. As an example from https://www.sweetwater.com/sweetcare/articles/my-behringer-fca6101616-turns-off-when-I-use-it-with-itunes-or-other-native-applications-on-a-mac-if-musicsound-is-paused-or-stopped/

 

This is a function of Mac OS X CoreAudio and not your Behringer FCA. Because the Behringer FCA devices are class-compliant and do not have their own drivers, they rely on Mac OS X CoreAudio. When music is paused or stopped in iTunes or another native Mac application such as your web browser, the CoreAudio drivers are suspended until audio playback is resumed. This is why your Behringer FCA momentarily disconnects and then reconnects when you resume playback.

 

We've since tried a firmware upgrade which has made it so that LED stays on all the time,but doesn't solve the underlying issue, so is actually less useful in terms of functionality.

 

We've identified a couple of possible solutions. The first we can try on site today is a bit ugly. It's continuously playing a track on one of the unused outputs of the soundcard, to try to keep core audio alive that way. The seconds we'll try back at base where we have the required adapters, is to try switching over to firewire (converted from thunderbolt) to see if that behaves any better.

 

Playing white noise out of one of the unused outputs using afplay starting at boot with cron seems to have fixed the issue. Whilst not an ideal solution it means we can leave a working setup.

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Playing white noise out of one of the unused outputs using afplay starting at boot with cron seems to have fixed the issue.

 

I suggest that playing a silent file/loop, would be just a little bit safer and have the same result?

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