warbling underwater sound on logic pro x playback

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scooterdoyle Author

Level 1

8 points

warbling underwater sound on logic pro x playback

hello

im new to forum and to logic pro x

here is my recording set up:

Rode K2 valve microphone- power supply- xlr cable to-appollo twin duo- thunderbolt cable to - mac book pro.

i am taking 2 1/4 inch jacks from stero output of appollo twin and connecting via rca(phono) jacks, into a yamaha ampilifier to a pair of old Hitachi monitoring speakers.

everytime i record something there is a strange warbling (underwater type) sound when i listen to the playback.

would really appreciate any help with resolving this issue

thanks

Posted on Dec 18, 2016 8:43 AM

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Answer 1

scooterdoyle Author

Level 1

8 points

Dec 20, 2016 1:53 AM in response to Pancenter

hi pancenter

your advice was excellent. i think it was a clock issue

went into logic pro x and in preferences was able to click on MIDI

which allowed me to then change the clock to "external or free"

this seems to allow the clock in logic to become a slave to the apollo twin.

distortion is gone.

This procedure is not clearly outlined in any of the apple documentation for logic,

which seems crazy to me as it is obviously a fundamental starting point for any interface set up....definitely something that should be addressed by apple .

also the twin seems to default back to 192 everytime i try to change it to any of the other sample rates.

is this normal??

however i don't mind this as being an old tape warhorse, the closer i can get to tape sound the better.

as regards file sizes...surely could i not just save files to an external drive and call them up whenever i need to mix etc???

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Answer 2

Pancenter

Level 6

14,788 points

Dec 18, 2016 10:47 AM in response to scooterdoyle

Possibilities...

First, use Logic's Preferences/Audio to set both Input and Output Device to the Apollo.

-What format audio file are you recording to Use either AIFF or WAV at 24-bit 44.1kHz as a test.

-A ground problem between the Apollo/Computer and the Yamaha/Hitachi Setup, especially if you're using a laptop and also if you're using an external monitor on the laptop. A low frequency hum and play havoc with audio.

-A digital clock problem, check the UAD Apollo software interface and Make sure the Apollo is the Master Clock.

(are you comfortable

-An unknown problem with the Thunderbolt/Computer interface.

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Answer 3

Pancenter

Level 6

14,788 points

Dec 18, 2016 11:06 AM in response to Pancenter

-A digital clock problem, check the UAD Apollo software interface and Make sure the Apollo is the Master Clock.

(are you comfortable

Haha... oops... unfinished sentence, are you comfortable with all the ins and outs of the Apollo software interface?

You should be able to set master clock, bit rate (24) and sampling frequency (44.1) there.

Also... you are speaking of playback within Logic and not a file you've bounced. If it's a bounced mix file, the it's the format you're bouncing to. A low rate Mp3 will warble.

Also make sure you don't have Logic's Varispeed enabled.

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Answer 4

scooterdoyle Author

Level 1

8 points

Dec 18, 2016 11:29 AM in response to Pancenter

thanks for taking the time pancenter

-both input and output are set to the apollo

-audio file format is AIFF ( recording at 192khz)

- the clock on apollo is set to "internal"

...i'm not sure what a "ground problem" is ?

i've been playing back from logic.

tried bouncing down an mp3 a couple of minutes ago and the distorted type sound is still there when i played it

ive been watching the levels and they look ok, not too hot, is there something simple i am missing here??

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Answer 5

Pancenter

Level 6

14,788 points

Dec 18, 2016 5:59 PM in response to scooterdoyle

scooterdoyle wrote:

thanks for taking the time pancenter

-audio file format is AIFF ( recording at 192khz)

ive been watching the levels and they look ok, not too hot, is there something simple i am missing here??

Yes, recording at 192kHz does not make sense... are you working with a company that requires you to record at that rate or send them 192kHz files? Do you have a Multi-thousand dollar listening room?

Are these all software instruments or are you recording audio, a mixture of both?

Try these settings:

96kHz (still overkill for most situations)

Logic's Preferences/Audio I/O Buffer Size 128

Higher sampling rates use more CPU and strain the system-bus, audio file size on the disk is 4 times larger than 48kHz which further loads the system-bus.

Try the setting above and see if the sound changes, if it does you will know where the problem is.

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Answer 6

Pancenter

Level 6

14,788 points

Dec 20, 2016 9:20 AM in response to scooterdoyle

The problem with using 192kHz is that your projects will have a limited size/number of tracks possible, take it from another old tape junkie, 96kHz is more than enough. More important than sample rate is bit-rate, so 24-bit always.

What you said doesn't sound right, Logic should pickup the sample-rate/clock from the audio hardware.

You should be able to permanently set the sample rate in the UAD/Apollo software Interface.

In Logic, look under Settings/Audio.

Settings are on a "per project" basis - Preferences are Global and stick for all Projects.

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