ALAC on Mac to AAC on iOS via iTunes Match?

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Level 4

2,246 points

ALAC on Mac to AAC on iOS via iTunes Match?

I''m a neophyte at using iTunes Match (iTM). The first is helping me fit my music collection onto my new iPhone 7s.

How to I most easily reduce the current ALAC library size on my Mac to a smaller AAC library on my iPhone 7s? Will iTM do this for me?

Most of my iTunes music collection is in ALAC format imported mostly from CDs. It is now 56 GB and will continue to grow. I am about to purchase a 64 GB iPhone 7s which I will want to use in place of my classic iPod. I will want more than the remaining 8 GB for other uses such as the SW overhead, pictures and movies. For my portable music the extra ALAC fidelity is not necessarily needed.

Will iTM download all my music to my iPhone so I can listen to it when I don't have an Internet or cellular signal or does it only download the music you are listening to in real time? If the latter then it will dramatically save space but might now work well on the road which is where I mostly use my iTunes collection. Could sync my iPhone with my Mac transferring the songs I like best, to use when I am not in cellular range without filling up my iPhone memory with my full iTunes collection?

If I use iTM will it download the songs in AAC format? If it does not download everything by default, can one limit the size of how much it downloads? Does it have a caching algorithm that deletes songs that have not been listened to in a specific amount of time?

I have read elsewhere in this Community about the issues of some songs not matching. So I should be able to get around that by syncing my Mac and iPhone but first I would need a second (smaller) copy of my iTunes library in AAC format. How hard would that be to create and maintain and how much extra space would it take (given 56 GB of ALAC data now)? How small would this AAC data be on my iPhone?

And lastly, how good is the audio quality of 256-Kbps AAC compared to ALAC? Can one often hear the difference?

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Summary of expected answers and questions they raise:

- The WAV/ALAC compression ratio is about 50%.

What is the WAV/ACC compression ratio or the ALAC/ACC compassion ratio?

In other words what would be the size of a 56 GB ALAC library when reduced in size to an AAC library?

- How easy is it to manage the duplicate AAC library on a Mac?

If this is small enough it may avoid the shortfalls of iTM.

- iTM only downloads the music you are listening to and only in AAC format. True?

This does not use much memory on a 64 GB iPhone.

What is the caching algorithm and how much space can I expect it to use?

Can I control how much space it uses to cache the music?

- I can sync a subset of songs from my Mac to my iPhone manually

for songs I want to listen to when out of cellular range,

for songs that do not "match" and

for songs I want to listen to in ALAC format. True?

I can listen to my other songs via iTM in AAC format,

downloaded in real time over the Internet or cellular data connection. True?

- How good is the audio quality of 256-Kbps AAC compared to ALAC?

Can one often hear the difference?

iPhone 5s, iOS 7.0.2

Posted on Oct 11, 2013 2:46 PM

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Answer 1

hands4 Author

Level 4

2,246 points

Oct 11, 2013 6:53 PM in response to hands4

I asked these questions in smaller chunks and got all my questions answered.

I can comperss my ALAC files on the fly when loading them onto my iPhone. So I will not need a duplicate libraary on the Mac and my entire ALAC library will fit with room to spare on my iPhone. This means I do not need iTunes Match. I thank all the contributors to my other questions for helping me piece this together.

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Answer 2

Oct 11, 2013 11:02 PM in response to hands4

Hi,

Not sure if I am answering you exact questions.

I'll explain how match works - it scans your iTunes library and will either match or upload your music. The matched version on iCloud will be 256 Kbps and uploaded files will be uploaded as 256 Kbps.

As a far as ALAC files are concerned, nothing happens to them on your computer unless you opt to delete and replace. With the files still on your hard drive, you can sync your iPod Classic as before. You can have them as ALAC or down convert 256 Kbps if space is an issue.

When you turn on match on your iPhone, all your music will be available as 256 Kbps. The tracks download as you play into a temporary cache - you will be able to play them off line. Alternatively you can download in advance.

Hearing a difference between ALAC and AAC? Only your ears can tell. Some can others cannot.

Trust this party answers your queries.

Jim

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Answer 3

hands4 Author

Level 4

2,246 points

Oct 12, 2013 6:35 AM in response to Jimzgoldfinch

Jim,

Thanks for confirming my answers. I learned from you and others that Apple (once again) has made it very easy to do what I want to do, which is to have all my music available on my iPhone at all times (even where cellular coverage is sparse). I specifically purchased a 64 GB version so I could replace my iPod classic (128 GB). My music library is 56 GB and growing so it will not fit in the 64 GB (minius overhead, pictures, movies...).

So I was considering iTunes Match. But it has some downsisides:

- It does not work where you don't have cellular or Internet service.

(I use my iPod regulary when I travel in the car.)

- I have read in this Community that there are matching problems with some songls.

I'm not sure why that would be a problem since it is supposed to upload all songs that are not matched.

So to compress my files onto my iPhone I was concerned about having to maintain a duplicate database on my internal Mac drive.

It is an SSD so I prefer to use space wisely on it.

It sounds like a pain to maintain.

I found out iTunes will convert the songs to AAC on the fly, so problem solved.

I found out the compressioin size is great.

56 GB on my Mac should be about 20 GB on my iPhone.

I also just realized I already have iTunes Match because I purchased it to use iTunes Radio without commercials.

I love some of the channels and others not so much

and I look forward to them fixing its initial major bugs.

So here is my conclusion;

- I will start by using iTunes Match to see if I have cellular reception problems while traveling.

- I will be listening to the same compression either way (256 AAC).

- If that has issues I will download my iTunes library

in 256 AAC format to my iPhone, at least for the songs I think I'll really need.

It should use no more than 32 GB, even once my library grows.

Summary:

Apple has made it simple again.

This Community has been very helpful.

Thank you.

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