Multiple bit resolution in itunes/iPod/iPhone

[robertp366]

I haven't found anything on search - perhaps my question is too vague.

I have several hundred CD (I own) and would like to access them at different bit densities for different devices:

iTunes: I stream music via Air Play to several Airport Express devices on various audio systems in my home. I have lots of hard drive space (5+TB) so I'd like to use "lossless compression" to get the best possible sound. I can really hear the shortcomings of the old 128 kb iTunes songs, especially for classical music.

iPod: I have a 120 GB iPod, so I'd like to fill this with at least 256(VBR) music

iPhone: with space limited to 32 GB, 256(VBR) kb gets me about 4,000 songs; at 128 kb I could fit most of my music.

i can sync all three in iTunes, but only at one rip density. At a minimum, i'D like to have Lossless on home system and 256(VBR) on the portables.

How can I manage multiple copies at different resolution, yet still keep them in sync as I add new stuff? I know I'd need to rip the original CD's several times; I just re-riped 500 CD's from 128 kb to 256(VBR) - straightforward, just took a few days of background disc stuffing while I worked.

Any help would be appreciated!!

Thanks

Robert

[jhollington]

By itself, iTunes 10 can automatically transcode your music to 128kbps when syncing to your iPod, iPhone or iPad. However there is no way to specify a custom bit-rate for this -- the setting is fixed at 128kbps.

If you're using a Mac there are Applescripts that can help manage this for you. I'd recommend a search over at Doug's Applescripts for iTunes. I'm not aware of any such solutions on the Windows side, unfortunately.

[S2_Mac]

AirPlay (and its predecessor AirTunes) streams Apple Lossless, up-converting on-the-fly as needed, and then outputs PCM from the Airport Express. So there's really no need to rip CDs to AIFF or WAV, and the space savings with Apple Lossless are significant. (If nothing else, it makes large-scale file transfers happen about 40% faster ;-)

If you can live with 128K AAC on both the iPod and iPhone, the convert-to-aac-on-the-fly sync options in iTunes would be the easiest route. Plus, your library would be easier to manage -- no need to differentiate between the lo-res and hi-res tracks when building playlists and configuring sync settings.

This is especially true if you use the Remote app on an iPhone or touch as a playback controller for AirPlay. The Remote app doesn't report on a track's file kind or bitrate, so your ability to easily browse hi-res tracks remotely is quite limited.

If you absolutely gotta have files with multiple resolutions, you should consider maintaining two libraries -- a "master" that holds all your lossless CD rips, and a secondary library (your current library) to manage lo-res content and sync the iPod and iPhone. It's no party doing it this way, but it's not a horrible task by any means.

No matter what you decide to do, post here again at iLounge before you start -- folks who have been-there-done-that can let you know about pitfalls and gotchas.

[robertp366]

Thanks for the replies.

With nearly 500 CD's, and a pile of really good vinyl as well, my biggest problem has been finding anything. iTunes and air play streaming via Airport express really made that easy - especially with the browsing capability of iTunes. To help, I've made over 100 playlists (some overlap). The biggest shortcoming of iTunes was the need to compress the music because of storage limitations - I could really tell in the music. My fall back was a pair of 300 disc CD carousels, which gave me full quality but tedious searching - I even made a filemaker database to help. Now I've essentially unlimited storage for iTunes, so I'm after a better strategy.

I know airplay uses lossless, but up converting a compressed file does not recover the lost info. But if I start with lossless, Airplay does an excellent job (I've done the tests). So for home audio, I'm all set to rip big Lossless files.

Now to manage the iPod and iPhone. 256 VBR does fine on the iPod with 80 GB and the iPhone with but 32 GB if I select just some playlists. I know iTunes will compress to 128 for the iPhone, but the music really sucks, so I'll stay with 256VBR and selected playlists.

Can I have two complete iTunes Libraries (lossless and compressed)? How would I switch between them? How about making dual sets of playlists in one Library, one set of lossless music for home audio, and one compressed for sync to iPod/iPhone vis "sync selected playlists"? (wow, that'd be over 200 playlists!)

Even better, can I put the lossless files on an external drive, and essentially down-select to the iPod set just by disconnecting the drive, Sync as needed, and then start up the external drive again?

Thanks for your help!

Robert

[jhollington]

Have you done actual blind ABX testing to determine if you can really tell the difference between a 256kbps VBR and the original lossless source? I don't doubt at all that you can hear profound differences at 128kbps, especially for classical music, but when doing proper testing most users find 256kbps AAC to be indistinguishable from the source, even when listening through extremely high-end earphones (SE530, UE18, etc). If you can't hear the difference through a set of six-driver UE18's there's no way that you're going to hear a difference through any kind of external speakers.

Blind ABX testing is important in this case as there's a definite placebo effect if you know which one you're listening to, and in fact even different volume levels can make one source sound better than the other when in reality there's little difference.

The point is that if you can't really tell the difference with a 256kbps file versus the original lossless then you'll save a whole bunch of time and frustration trying to maintain two iTunes libraries for no tangible benefit. Full lossless rips are still a great idea for archival purposes -- should you want to transcode to a different format or bit-rate in the future it makes it very easy -- but in that case you wouldn't really need to worry about keeping those in an active iTunes library, and could simply put them away on an external hard drive or other media.

I used to fret about this a great deal years ago until I did the real blind ABX testing using the aforementioned earphones and realized that I couldn't tell the difference between even a 128kbps AAC and the lossless source for about 80% of my music library, and couldn't find a single track, even among some of my favorite classical music, that I could differentiate at 256kbps. That discovery was actually very liberating for me

That's just me, of course -- your actual ears may vary.

All of that said, however, to answer your more specific question about maintaining two sets of music... You can either maintain them as two separate libraries which you can switch between either by using a library manager or simply holding down the SHIFT key (Windows) or OPT key (Mac) when starting iTunes. This will give you the option of choosing a different library. The problem in this case is that you'd have to switch back and forth all the time to ensure you were using the correct set of music, and maintain two identical sets of playlists if you wanted to keep things the same on your iPod/iPhone as your main library.

Alternatively, you can go with the same content in both libraries and two sets of playlists. You can even use Playlist folders to keep them easy separated. However in this case you'll lose the ability to browse by artist, album, and genre unless you're willing to live with the duplicate music -- you'll basically be restricted to only playing music from your playlists. You'll also still have the headache of keeping your playlists in sync so that your lossless and compressed playlists match, and Smart Playlists that use criteria like last played time and count will essentially be useless because those play counts won't match up the way they should as you're listening to two different tracks. Ratings will also be a nuisance to manage, sine if you rate one track on the go you have to ensure that you match up that rating when you get back to your main iTunes library.

The bottom line is that keeping two sets of your music is doable, but it's definitely not simple as iTunes was never designed to effectively work this way.

[robertp366]

Thanks again for your help.

I agree that 256VBR is really, really good for most uses. Even the 10 speaker Harmon Kardon set in my BMW, or my $400 Entymonics earphones don't reveal much loss (but some). For both of these, the 128kb really shows how good 256VBR is.

The place that Lossless shows its strength is at the low frequency ends, and on wide dynamic range music, such as Carmina Burana, or a top end recording of the 1812 Overture or the japanese Kodo Drums, at the high-power, low-frequency ends. (The big drums get muddy, the guns just get clipped). The small shortcomings only stand out on my home systems, where I have 1000 watt base woofers and an array of mid and high speakers. It's probably less than 1% of the content of 1% of my music. And one of the reasons I still have subscriptions to the LA and Boston Phil. Still can't beat live.

The limitations are the rough equivalent to WOW on turntable/vinyl systems used to have, which came from unstable rotation speeds at low frequencies. The CODEC's do too. We've also become almost immune to the discernible 6 db roll-off at high audio frequencies from the 44 khz CD sampling (one of the reasons live and vinyl still exist).

(Referring to 256 VBR) my Dad used to say : "This is really, really good. Can you do something better?"

So far none of the options gains enough to counter the costs - but I really do appreciate the suggestions. Maybe I should just do Lossless versions of the few pieces that seem to matter, and accept the duplication.

But I'm still open to ideas. Maybe iTunes will make a leap! Again, thanks for all the ideas!!

Robert