This compression thing

Well a bit of caculation tells me that my 200 gig harddrive (lets say 170gigs actual) is not going to hold many CDs, even allowing for a CD actually holding an average of 500 megs, thats still only 350 CDs.

So to compression, Paul here goes on about lossless compression?

The criteria are however that I will be using itunes, for importing and any compression, itunes is the lynch pin in my whole operation changing this software simply is not an option.

There for allowing what compression itunes has what would be best, I am thinking something in the AIFF format as this is the format of the CD in the first place, but what do you guys think?

 

No chance of bunging-in an extra drive solely for the itunes library, to keep the data uncompressed?

If you are considering using lssy cmprssn, then the Lame encoder is highly regarded. It is available for OS X 10.2+ and iTunes 4 here.

 

AIFF is no compression at all. I think it's just basically a slightly different version of WAV (which is also uncompressed).

With iTunes there are no lossless compression formats, only MP3 and AAC, both of which are lossy. I think you'll either have to live with 320Kbps MP3 (the best quality MP3 there is) or get a bigger hard drive.

Michael.

 

I may be wrong but AFAIK the AIFF format is not compressed at all so you won't gain any space through this.

Try compressing a CD at high bit rate in AAC compression (go to preferences then importing, Select AAC encoder, Use the custom setting and set bit rate to 320kpbs, sample rate to 44.1khz - I don't think its worth using 48khz as the cd is already in 44.1, and set channels to stereo) then import the same CD as AIFF. AB the two to see if there is any significant quality loss (I very much doubt there will be any noticable difference at all).

You can then experiment with dropping the bit rate until you notice the sound deteriorate. You'll then know the optimum compression rate for music storage on your system (the bit rate above the one you noticed the deterioration)

HTH

Footnote AAC is reckoned to be better than MP3 for equivelent bit rates

 

Gary,

I'd agree with Slaphead, try the compression at higher rates. I was listening to some 192kbps files last night and I'd be hard pressed to tell the difference between them and a WAV file, it was far more subtle than say a cable change

 

Here's a thought.

Just how long are you intending to spend copying 350 CDs to your hard drive. Thats likely to take several months.

Now, just what protection have you planned to cover against a drive failure? I'm guessing none.
Bearing in mind that drives are not that expensive, wouldn't it be worth the effort to stick a RAID drive controller in and two pairs of big drives? That would give not only masses of space, but also some form of data protection which could save you months of data recovery. Surely that's worth a couple of hundred quid?

 

I concur.

I've been using AAC @ 256K since iTunes for PC was released, and have never had better results.

Felix, the G5 only has 2 HDD bays, the 200gig drive is the second.

 

Take a large HDD (say 400Gbish) compress all your CDs to the max --->>> voila, enough music (albeit with poor sound quality) to listen to for the rest of your life without ever needing to replay a single track.

 

Mr Sukebee, although I agree it will take a while to import the CDs, it does infact only take at the most 4-5 minutes to import each CD, so I don't think 3 or 4 months is realistic, more like a few days.

Importing for the ipod took around three days (with faffing, going to work etc) and this is around 100 CDs.

I would imagine going down the route you suggest is going to blow my budget of £350 out of the water, so for the time being at least, no thats not an option!

 

gary,
i'm sure that you can get external usb2 or firewire drives from 40gb up. just get yourself a hefty powered usb hub and voila a practically infinitely expandable array of drives (well up to the limit of space and the connection standard really). alternatively there are network enabled hard drives which you just plug into an ethernet port (via a crossover cable or a concentrator) i've seen these at 500 quid for 1/2 a terrabyte.
cheers


julian

 

This just occurred to me, but why not use compression on the actual drive?

I mean on the PC at least, there is something called Drive Space. This basically enables a data compression method on any files that go to your hard drive. It will slow the hard drive down as it needs the CPU to do the compression/extraction, but you get a whole lot more music on that way.

Its not normally bothered with these days because most program files use some sort of compression as it is, but if all you want to store is uncompressed audio then it will give at least double the capacity.

 

Felix, thanks for the link I have downloaded it.

 

Julian could you say which particular models? I have been looking for a network drive without success.

 

steve,
lacie were the ones i was looking at. they do network NAS storage from 368 (inc vat) for 80 gb to 1/2 a terrabyte for just over 1k ukp however these drives support usb and firewire expansion and they also do a 1/2 tB drive for just over 400 quid.
so i was a bit optomistic on the price.
have a look at http:\\www.lacie.com/uk
cheers



julian

 

The great import begins!



I am encoding in 256 AAC to my brand spanky new harddrive. Itunes will allow me to save straight to the harddrive at the first level. This is handy as the itunes catloging application I am using will paste the album cover on each album folder, so I will have a harddrive first level of all the imported albums in glorious OSX full size icons. Nice.

My DAC is winging its way to me as we speak and will be here tonight. My super long optical cable hasn't arrived yet but I can't wait any longer so I bought a cheap one in town!

Will let you know how it sounds tonight, lets hope I didn't screw up 'cause I don't have my naim CDp anymore

 

good to hear things are on track

 

Certainly Are!

The Arcam Delta Black Box 3 is now in place. Well not in place exactly I am waiting for me long optical lead so I can place it on the hifi rack.

In the mean time it sits here:



The sound is supurb. Of course I have sold the CDi so I can't compare to that but its a lot tider than the DVD player for what thats worth.

The compression ratio of 256 on AAC did lead to a bit of digital hash on the treble making it quite difficult, so I upped it to 360 and it all seems just fine now.

Does anyone know about this arcam? Its second hand obviously with no instructions. I have 4 buttons 3 a obvious the forth is a 'Phase' button if I press it, it switches between a red and a green led. You can hear an audible pop in the sound but apart from that I can't detect a difference, would anyone know if I should have it on green or red?

 

have it on green to match your other kit if you can't hear a difference. it probably reverses polarity on the outputs - i.e. if you connect red to black and black to red on your speakers you'd be doing the samer thing. it only really makes a difference if one channel is out of phase with the other which leads to atc like bass (i.e. none).
i'm waiting with baited breath to hear what it sounds like.
cheers


julian

 

Hi Julian.

Initial reacton is that its OK. I think I need to re-consider the compression settings. Right now I am getting quite a 'bloom' on the bass and treble can be difficult. In fairness though I am going to around 10.30 on the pre amp which is louder than I ever played the CDi for extended listening.

I am however confident that once the right setting is found I will be enjoying this emmensly.

One thing is for certain, it blows the anolog out into the weeds, however I am fightin gthe mac at the moment as it insists on playing system sounds out of the stereo even though it should be coming out the sound sticks!

I have't used itunes catalog yet which will enable easier selection of tracks but am chiffed the albums are being placed on the root level of my new harddrve, once the album covers replace the folder icons I will have a window full of albums, excellent!

I am importing a David Bowie album in 44khz WAV to see how that compares.

 

Ah.

Now this does sound good. I have imported the bowie album in Wav at 40 odd KHZ and it sounds a lot better.

Trouble is the tracks are weighing in heavy, infact I might as well import them without compression.

I think its fair to say Paul Birkett is way off the mark with compression, in general it sounds awful!

I am going to try a lesser setting on the wav see how that goes, then I have LAME to try