[kenreau]

This is most likely addressed some place, but I've not found it in a few searches, so I'm raising my hand here.


I have approx. 1 TB of music I keep on an outboard HD that feeds my Mach2Music macmini.  The music files are all AIFF uncompressed format.  I refer to this as my "Master Music Library" HD.  This is part of a dedicated 2 channel music only system. 

In our household we have roughly 10 other apple devices (imacs, ipad, iphones and assorted ipods).  Given the typical use of these other devices (wife and teens and car stereo) and their limited HD sizes, I want to provide a compressed version of the music library to use for these devices playlists and to keep my "master" music HD out of their influence.

I think I would like to set up an independent music library with a compressed file format (with reasonably good sound quality, say something at least around the 256kbps range).  I will also be using this compressed library for my headphones and car stereo hd.  We don't use any windows products, so no concerns with their compatibility.

Question #1
I could use some input on which compressed file format to use. 

My current preference is to use Apple Lossless or AAC(MPEG4).  In my initial searching, I was thinking that using Apple Lossless would be adquate.  But, looking at this music file format comparison screen, I'm perplexed. 





The Apple Lossless would probably work fine for my car and headphone ipods, but not quiet enough compression for the other family devices (8GB to 16GB portable devices)

Is there a reasonable compression format some where between the Apple Lossless (33% compression) and the AAC (90% compression)?



Question #2

What is the best way to provide this compressed file format music library for everyone to access? 

I have a spare 1 TB drive available and was just thinking of cloning my master music files to it by importing them in the new compressed format.  Then have the new compressed format drive attached to our office iMac to act as a central server iTune music hub.  Set it up for local sharing so the kids iMacs can link to it for their use.  Is that a good approach?

Thanks
Kenreau

[srb]

Is there a reasonable compression format some where between the Apple Lossless (33% compression) and the AAC (90% compression)?
Kenreau

When you converted to AAC with ~ 90% compression, you used the default 128kbps bit rate.  You also have the option to use higher bit rates with AAC compression for better quality.  You can choose the "iTunes Plus" setting which will give you 256kbps with variable bit rate for ~ 80% compression or use the "Custom" setting and select 320kbps with variable bit rate for ~ 75% compression.
 
Steve

[Crimson]

Really no need to make a low-res clone. All your Macs can access (but not modify) your master library via Home Sharing. These Macs can then be synced with various iPhones, iPods, and iPads (enable the 128 Kbps music transfer option to save on space of the mobile device if desired). If using a single Mac, each mobile device can sync with its own playlist.

Alternatively, you could try iTunes Match and have all your music everywhere without syncing or sharing.

On a side note, I use 256 Kbps AAC when I need to compress. Not Apple Lossless.

[jparkhur]

FWIW.  I have a main iMac that all the music is on and a back up to a secondary library.  I have 4 iTouches, some old some new, two Apple TV2's and two other laptops that ALL access through home sharing no matter the size or resolution of the original iMac files.  I have though also of having just one AIFF library, but I could not fathom the actual size of it.  I currently have all live concerts from DAT in AIFF, and all the other stuff in iTunes plus for the most part = 500 gigs at this point.  I have kept all the CDS in a closet for use if needed, but otherwise no issues. 

[jparkhur]

I also think that stereophile did a double blind study on the compressions and whether or not people could tell the difference between them.  MOST (this is from what i remember) high quantity music listeners could tell a difference between mp3 compression, and only 50 percent between Apple Loseless and straight cd.  NOW- i would guess that depending on your ear and equipment, DAC for sure it may change, but i this case everything constant......   

THE JND of 50 percent    most of us would not matter, I think i can hear a difference between basic 16/44 cDS and MP4's for sure, Lossless.. not perfect.. depends on the music sometimes.   Lets do a psychological double blind ourselves....

Jon

[jparkhur]

Some Good articles.

http://ese.wustl.edu/ContentFiles/Research/UndergraduateResearch/CompletedProjects/WebPages/su10/AlexBenjamin_AudioCompression.pdf


http://www.robtoulson.rt60.co.uk/rt_docs/IN2010_BC-RT-JP_DynamicRangePPT.pdf


http://www.pcworld.com/article/195957/music_compression_test_how_good_are_your_ears.html

[kenreau]

Steve and Crimson, thanks very much, great to learn that.  I will do some more reading on how to implement those ideas.  It appears the 256 Kbps AAC is the format I will use.

Is there a good reference site, or how-to book, on how to set up these various features?  I used an iTunes for Dummies from the library for a short time but did not really find it helpful (as well as out dated).  The Apple website can be a little overwhelming to find this stuff as well.

Thanks again,
Kenreau

[srb]

The website iLounge.com has a lot of good resources on all aspects of iTunes, iPod, iPad, iPhone, etc.
 
as well as a selection of tutorials (Articles > Tutorials)
http://www.ilounge.com/index.php/articles/archives/tutorials
 
Steve

[skunark]

Steve and Crimson, thanks very much, great to learn that.  I will do some more reading on how to implement those ideas.  It appears the 256 Kbps AAC is the format I will use.

Is there a good reference site, or how-to book, on how to set up these various features?  I used an iTunes for Dummies from the library for a short time but did not really find it helpful (as well as out dated).  The Apple website can be a little overwhelming to find this stuff as well.

Thanks again,
Kenreau

Even Apple.com has several good documents on how to do this.

If all of these devices share the same iTunes account and is either an iPod Touch or an iPhone, then make sure you have iOS 5 as you now can wirelessly sync if you leave your mac mini and iTunes running.  As Crimson pointed out there's no need to keep two copies if you are fine with the 128k AAC file.   

If you want a 256k AAC file don't forget about the iCloud/iTunes Match, which it can upload all your songs (lossy or lossless source) to the account and any device logged into can then download it as a lossy 256 AAC and no mac mini/iTunes required.    There are unique rules about how it uploads lossless files and tags, but either the download/sync/stream will be a 256 or 320kps AAC file.  This will cost you $25 a year, with a device limit of 10 which also includes the iTunes that uploaded it along with any Apple TVs in the house.

[kenreau]

Thanks Steve and Skunark.  I will explore the iLounge forums.  I can't seem to get the hang of the Apple site navigation to what I really need.

Kenreau