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Resample tickbox in Aggressive Device Editor in Audio MIDI Setup

Who can tell me what the 'Resample' tickbox does, in the Aggregate Device Editor. It resamples to what? And why should I (not) use it and when?
User uploaded file

G4 dual 1,25 FW800 1792 MB RAM Just mess with stuff!, Mac OS X (10.5.7), Nikon D70

Posted on Jul 3, 2009 7:50 AM

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Posted on Jul 3, 2009 9:15 AM

Hi Erik:

A bit vague, but I believe that theoretically you check resample in either of two cases:

-You need some devices to resample because they were set to a different sampling rate, you change them, and you want the Aggressive Device settings to update itself
-When you have devices not designated as clock master.

In practice, I haven't found much use for this, although once it did solve a digital noise problem. Most of the time I've left it alone.

Equally good results can be achieved by slaughtering a chicken and dancing in the bloodied feathers, as this aspect of OSX seems more to do with a black art than science.
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Question marked as Best reply

Jul 3, 2009 9:15 AM in response to Eriksimon

Hi Erik:

A bit vague, but I believe that theoretically you check resample in either of two cases:

-You need some devices to resample because they were set to a different sampling rate, you change them, and you want the Aggressive Device settings to update itself
-When you have devices not designated as clock master.

In practice, I haven't found much use for this, although once it did solve a digital noise problem. Most of the time I've left it alone.

Equally good results can be achieved by slaughtering a chicken and dancing in the bloodied feathers, as this aspect of OSX seems more to do with a black art than science.

Jul 3, 2009 3:57 PM in response to Pancenter

Still, the big question is: why is this not described anywhere? I already exhaustively searched the KB, but zilch.

I once hooked up an USB headset with a built in 16 bit 32 kHz AI, I made an Argh!Device with the Built In audio, and I ticked the resample boxes (in different configs) expecting it to either upsample the headset mic input to 44.1, or downsample the Built In to 32. Needless to say, neither happened. There was no difference whether I ticked whatever resample box.
Could they be orphaned tickboxes?

Jul 3, 2009 5:22 PM in response to Eriksimon

Hmm… I'm curious now, too.

I found this:

http://forums.dv247.com/logic/1136-logic-motu-828-mk-ii.html

in which appears:

+Each Aggregate device uses one of the included hardware devices for a master clock source, and by default this is usually the clock Mac's built-in audio hardware. However, you can change the clock source by simply clicking the Clock radio button in the structure list for the device whose clock you want to act as the master. If you run into problems with clocking Aggregate devices, you might notice that each device in the structure list also has a Resample option, which performs a sample-rate conversion at the current sample rate that effectively reclocks the incoming audio to the master clock.+

Much like Pancenter said above.

It does work. If I aggravate two of my interfaces to a 48kHz session, with one of my devices (A) WC'd to a 48 clock, and acting as master clock, but the other set to 44.1 and I click resample, device B changes. I guess it depends on the device.

@Caramby
A pleasant 95 (35C in proper degrees)

Jul 3, 2009 6:18 PM in response to John Alcock

Okay John, I looked again and it is the device that is aggravating. The headset won't be aggregated, look at the total number of inputs:

This is what should happen, two devices, each bringing two ins and two outs:
User uploaded file

Here you see what happens when the headset is the clock master:
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...and here the other way around:
User uploaded file

Conclusion: the headset is an inaggregateable device. When it is clock master, the outputs of the Built In can't be added, and when the Built In is master, the headset can't be added. So the resample function can't work either.

Jul 3, 2009 7:34 PM in response to Eriksimon

Eriksimon wrote:


Conclusion: the headset is an inaggregateable device. When it is clock master, the outputs of the Built In can't be added, and when the Built In is master, the headset can't be added. So the resample function can't work either.


The USB mics (Samson...etc) are seen only as an input device which allow them to be used as an aggregate device with built-in audio. I wonder if it's because your Logitech headset has a stereo out and a MONO in (correct?) that confuses Apple's standard USB/audio protocol.

In Audio/MIDI setup, is your built-in audio set to 2-channel 16-bit In/Out?

pancenter-

Jul 4, 2009 1:22 AM in response to Pancenter

Pancenter wrote:
Eriksimon wrote:

The USB mics (Samson...etc) are seen only as an input device which allow them to be used as an aggregate device with built-in audio. I wonder if it's because your Logitech headset has a stereo out and a MONO in (correct?) that confuses Apple's standard USB/audio protocol.

In Audio/MIDI setup, is your built-in audio set to 2-channel 16-bit In/Out?


Yes.

Resample tickbox in Aggressive Device Editor in Audio MIDI Setup

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