ALAC to AIFF and Time Machine Backups

Posted by: Richard Lord on 03 January 2015

I have just completed the conversion of my iTunes Library from ALAC (apple's Lossless but compressed Codec) to AIFF, Apple's uncompressed full on Codec, I suppose their nearest to WAV.

 

Having done it, I can certainly hear the improvements in SQ. Difficult to describe in words, but a definite real improvement in detail. After a while, I thought it time to do a backup using Apple's in-built backup software, Time Machine. Then I noticed something very interesting.

 

I was trying to listen to one of my favourite test tracks from Rumours whilst Time Machine was backing up iTunes on my Mac Mini. I found it rather boring, well not quite that, but not nearly as involving as it is usually. So I left it until the backup had completed, which it has now done. 

I am listening to the same album and I have no doubt, it sounds far better. More involving and an altogether better sound.

This is suggestive that we ignore other activities that a computer has to cope with at our peril. Of course, I might be mistaken, or perhaps the mains quality was sub standard an hour back. Maybe. 

Meanwhile, I will be much more careful of when to listen. As I only occasionally nowadays make changes to my music, I will turn off automatic TM backups. I certainly advise turning off automatic backups, especially if doing any comparative listening. 

 

Has anyone else had a similar experience?

 

Happy Listening,  Richard

Posted on: 03 January 2015 by winkyincanada

I've had the opposite experience. No matter how hard I use my Mini whilst it playing (reading, decoding, converting and recompressing video, for example), it always sounds excellent. Are you sending the files or bitstream over WiFi (maybe using an AE) or via direct connection all the way from the file location to the DAC? Not that this would explain your perception.

Posted on: 03 January 2015 by George J

Quite.

Posted on: 03 January 2015 by Richard Lord
Originally Posted by winkyincanada:

I've had the opposite experience. No matter how hard I use my Mini whilst it playing (reading, decoding, converting and recompressing video, for example), it always sounds excellent. Are you sending the files or bitstream over WiFi (maybe using an AE) or via direct connection all the way from the file location to the DAC? Not that this would explain your perception.

 

No WiFi. I use USB direct connection into my V1. However, I wonder if this perception is in any way related to my converting from ALAC to uncompressed AIFF. It it is my experience. I am not claiming anything else. 

 

It it is interesting that PS can hear the improvement of WAV over Flac. I could certainly hear the improvement that AIFF offers over ALAC. Maybe, if I had not done the conversion the subtle difference might have gone unnoticed.

 

 

Happy listening,  Richard

Posted on: 03 January 2015 by J.N.

That's interesting Richard. I noticed a significant SQ kick when I updated my iMac's OS to Yosemite a couple of months ago. I was expecting no change whatsoever, so it was certainly not an 'anticipated' sonic improvement.

 

It has been suggested that this was partly due to a digital 'sweep out', enabling the CPU to work more efficiently at handling the data flow and conversion.

 

A domestic computer is potentially an electronically 'noisy' environment, so it makes sense to dedicate a device such as a MacMini to the task.

 

AIFF sounds audibly better than ALAC for sure. I have my CD's ripped in the former format.

 

John. 

Posted on: 03 January 2015 by Jude2012
Hi Richard,

In respect of ALAC vs AIFF, this is logical due to the slughtly less effort needed by the system to process AIFF.

Also the degradation of SQ while using TM is also logical as the system will be busier (especially if is backing a lot of changes such such as your library format change).

The items to turn of during music replay are: TM, Spotlight, and other  uncecesary background programme.

I have also turned off: wifi, infra red and Bluetooth and noticed a very subtle improvement.

I have also used scripts from a well know site to switch off other items of Mac OS.


Audirvana ensures that the typical stuff such as TM, Spotlight etc are turned of during music play.  It also plays from RAM to avoid being inteference from othe aspects of the system.  It also by passes Core Audio and uses its own audio engine - Izoptope .(you can still use Core Audio as an option- I prefer Izoptope, which comes with Audirvana).

Audirvana can be used with iTunes and Apple Remote.

Audirvana is a great programme as it is so flexible and gets the best from a Mac.

HTH

Jude
Posted on: 04 January 2015 by Bart

My local dealer commented to me that some of their customers who use Time Capsules find that the Time Machine backup process can cause glitches in other network functions while it's going on -- something about the Time Machine backup protocol getting priority.  They advise people to disable the backup process while listening to music if it helps. 

Posted on: 04 January 2015 by Richard Lord

Thanks all. I tried Audirvana 2 but I was not convinced, in fact I thought the bass was not as clear. So I have removed it. 

 

I think all this proves we all perceive sound differently. What is an obvious improvement to one is not the least obvious to another. I have always said there is no right or wrong. As long as we are happy with our system sound, then that is all that matters.

 

Happy listening,  Richard