An Experiment for Mac Users

[earflappin]

David, what interface are you using between your Mac and DAC? I'm using FireWire between my iMac and Metric Halo LIO-8 and I cannot hear the difference between stock iTunes, Amarra and Pure Music for example. Nor can I hear the impact of solid state drives versus spinning drives, etc. It makes sense to me as a properly implemented asynchronous FireWire interface should make things such as CPU latency irrelevant.

 

[davidR]

Interestingly enough I'm using firewire; a modified Digidesign 003 pro interface connected via Audioquest 1394-1 6 to 4 pin firewire cable, slaved to a Black Lion Audio Microclock MKII via the 003's word clock input. Black Lion has graphs on their website comparing the internal clock of the 003 to the MKII and the jitter is a magnitude lower. They also have said they tested the internal Microclock they use in their modifications to the external Microclock on the 003 and the jitter measurements remained the same. They used the Audio Precision SYS-2722 for their tests. I use Itunes and Amarra both run off a RAM Disk using Snow Leopard on a 8 core Mac Pro using WD Raptor hard drives.

 

[astaroth]

Sorry to bring back this thread from a certain death. I'v just discovered "cbarber" applescrip for renicing Amarra, itunes, and coreaudio.

 

After some experiments with the "sudo renice" on the terminal, it's was pretty clear just after the first try that this little tweak was a no brainer. Much better soundstage. Voices and instrument are much more fuller.

 

So i have setup the applescrip from "cbarber" and it's perfect! But i'm a little on the freak side when it comes to extract the most from my system. From what i'v read, The maximum value we can attribute is -20, giving the most ressource the the reniced process. And if you check the scrip, the renice values for amarra, itunes, and coreaudio are -17, -16, and -15 respectivlely.

 

So is there a reason that those 3 values are not at -20? I did change the scrip with all 3 values to -20 and quite frankly, didn't realy heard any differences from the scrip with the original values.

 

Did i miss something or it's perfectly normal? Is there any reasons for these specific values?

 

Thanks!

 

[silverlight]

Now that Amarra plays from a playlist (and now with 2.1 memory and playlist), I max Amarra and then core audio next, followed by iTunes. I also reduce priority to a few processes (like remote / VNC which I use to control the headless mini). I'm sure the experts will chime in here though...

 

[Olli Ilaja]

I am trying to renice Pure Music, Itunes and Coreaudio and got the message that Reniced Pure Music with PID, but there is no numbers. Other messages are reniced iTunes with pid 91 and reniced Core Audio with pid 268 but there is no numbers with Pure Music. What is wrong in this script below?

 

 

--Run Pure Music

tell application "System Events"

if (get name of every process) does not contain "iTunes" then

tell application "iTunes"

launch

delay 3

end tell

end if

if (get name of every process) does not contain "Pure Music" then

tell application "Pure Music"

launch

delay 5

end tell

end if

end tell

 

--Get process IDs

set theConfirmation to ""

set PureMusicPID to do shell script "ps -A | /usr/bin/grep Applications | /usr/bin/grep Pure Music.app | awk '{print $1}' | head -1"

set CoreAudPID to do shell script "ps -A | /usr/bin/grep coreaudiod | awk '{print $1}' | head -1"

set ItunesPID to do shell script "ps -A | /usr/bin/grep /Applications/iTunes.app/Contents/MacOS/iTunes | awk '{print $1}' | head -1"

 

try

do shell script "renice -17 -p " & PureMusicPID user name "XXXX" password "XXXX" with administrator privileges

if (result = "") then

display dialog ("Reniced Pure Music with PID " & PureMusicPID) buttons {"OK"} giving up after 5

end if

on error errText

display dialog ("Pure Music error: " & errText) buttons {"OK"} giving up after 5

end try

 

try

do shell script "renice -16 -p " & ItunesPID user name "XXXX" password "XXXX" with administrator privileges

if (result = "") then

display dialog ("Reniced iTunes with PID " & ItunesPID) buttons {"OK"} giving up after 5

end if

on error errText

display dialog ("iTunes error: " & errText) buttons {"OK"} giving up after 5

end try

 

try

do shell script "renice -15 -p " & CoreAudPID user name "XXXX" password "XXXX" with administrator privileges

if (result = "") then

display dialog ("Reniced Core Audio with PID " & CoreAudPID) buttons {"OK"} giving up after 5

end if

on error errText

display dialog ("Core Audio error: " & errText) buttons {"OK"} giving up after 5

end try

 

[Bob Stern]

would be the problem.

 

Try renaming the app (and the reference in the shell script) to PureMusic without the space.

 

There's a way to deal with names having spaces in a shell script, but I'm too lazy to look it up.

 

[Olli Ilaja]

I thought that it would be the problem with spaces also. It was the same problem with Amarra Junior but everything went up fine with Ayrewave and Audirvana. Must be the spaces. I will try this at the evening. Hope this would help.

 

[elcorso]

Disabling Spotlight is very easy with an APP I found: "Spotless".

They have versions for most of the running the OS X's, 3.0.0 is the version No. for Snow Leopard.

 

It is shareware and cost about $16.-

 

This way you don't have to use Terminal.

 

Cheers!

 

elcorso

 

[wgscott]

There's a way to deal with names having spaces in a shell script, but I'm too lazy to look it up.

 

There are two ways:

 

1. Escape:

 

Pure Music.app

 

 

2. Quotes:

 

"Pure Music.app"

 

 

 

[wgscott]

If you really think that renicing these processes makes a difference, why not simply enable the root account and play your music from that?

 

 

 

[[email protected]]

Hey i had seen an interesting experiment of the Mac users which was named as penmanila on windows 7,it was an interesting experiment.

The Experiment mentioned in this blog is quite difficule for me because i had tried many times ago but was not successful i will again try it by following your instructions and reply you.

 

Online advertising agency

 

[hoka]

As a result of this topic I decided to kill spotlight via a shellscript but that has somehow also killed puremusic! I get no more sound via it!

 

edit: I got sound back somehow????

 

weird glitch I guess