[Keith Henderson: OFF: Questions for techies]

Wed Oct 28 14:07:41 EDT 2009

On 28 Oct 2009, at 17:21, M Holmes wrote:
> [Keith wrote:]
>> I am not
>> particularly picky about retaining the maximum sound quality of the
>> original, so I thought I would just allow iTunes (is there a problem
>> with that?) to rip them into the current state-of-the-art for iPods
>> and such, which I gather is still MPEG-4 (file suffix .m4a).
>
> I thought MP3 was sound and MP4 some sort of video?

MPEG-4 is a specification for both audio and video.  The AAC scheme  
is part of both the MPEG-2 (also audio and video) and MPEG-4  
specifications.  Technically, MP3s belong to the MPEG-1 Audio Layer 3  
specification.

> For MP3, I tend to record at 256 or 192 rather than 128 because I do
> find the sound loss at 128 annoying, but everyone has a different
> tradeoff between memory space taken and sound quality.

I tend to make both Apple AAC files (for the iPod) and MP3 files (for  
discs that play in the car stereo) at minimum 192 (typically, I use  
variable bit rate or VBR files).   But the bit rate at which you are  
happy will depend on many things, like your ears, your speakers/ 
headphones, ambient noise, etc.

>> Anyway, my real question is about the storage device I should buy.  I
>> am looking at a Seagate FreeAgent PRO desk model with 640 GB  
>> capacity,
>> as they are on sale for only $70 with free shipping to boot.
>
> I have a 500Gb Freeagent drive, but I have to say it's been
> temperamental. It's powered from the USB (separate USB power lead if
> needed) and sometimes the laptop won't recognise it. My suspicion is
> that occasionally it's wanting more power than the laptop can supply.
> I'd give some thought as to whether to get a mains-powered unit, but
> again there's portability tradeoffs.

I originally used 500 GB and 750 GB Western Digital drives, but when  
my collection outgrew those I moved it to a LaCie 1TB drive, with  
abother LaCie 1TB drive as backup.  Of course, my iTunes library has  
all my music (or all the music I've so far ripped) saved in Apple  
Lossless format, so my drive-space requirements are quite a bit  
larger than they would be if I were storing only lossy AACs or MP3s.

>> Does it have to be plugged in?
>
> Nope, but see above.

Indeed, larger drive sizes (not surprisingly) tend to require more  
power -- often more power than can be practically supplied from the  
computer itself via USB, Firewire, etc.  All my external drives of  
500 GB or more have external power supplies.

>> I mean, my iPod does this, and it is effectively an external drive,
>> so why not this one too? (such is my thinking) Perhaps it needs a lot
>> more power though.  (?) But anyway, I ask because I want to have
>> something I can carry to Europe (eg) and still use without any
>> trouble.  (On that note, what is the Windows/Mac compatibility of
>> externals, assuming it will be used with Windows XP first?) So if it
>> does have a plug, is it at least designed to be compatible with  
>> 220/50
>> power?
>
> Usually they'll have a transformer which will convert to 12 or 5  
> volts.
> Most such transformers will work abroad at different mains voltages,
> though if it doesn't come with the mains plug adapter kit (I always
> check that because it's an extra cost to get it otherwise) then you'll
> need to buy one.

Mains plug adapter kits tend to work fine with most external hard  
drives I've seen.  Virtually all external hard-drives really on their  
"brick" power supplies to feed them the right kind of electricity,  
and in most cases you can send virtually any electricity into the  
"brick", and the brick sends the right electricity to the drive. :)   
I bought one of my WD drives in the UK, the other in the US -- I used  
the US one in the UK with a simple travel adapter, and now I use the  
UK one in Colombia (which has US-style electricity) with another  
travel adapter.  No problem.

Virtually all external drives come pre-formatted for Windows.  They  
can, of course, be read by Macs (Macs being clever like that), though  
I have encountered read-write problems with Windows formatted drives  
(especially with large file sizes), so I tend to just blitz any new  
drives when I first plug them in, reformatting them for Macs.

If you are just storing MP3s/AACs, the file sizes may be small, so  
you might not run into any problems when plugging a Windows-formatted  
drive into a Mac.  However, I would investigate the issue in greater  
depth if you really wanted cross-platform compatability.  (I don't --  
I just use my drives with my Macs -- so it hasn't mattered to me.)

> Also, non-moving memory is also
> dropping in price, though very large chunks of it are still quite
> expensive compared to hard disk drives.

My experience is also that "non-moving" memory tends to be slower,  
still, in comparison to hard drives. This may be an issue when  
slinging audio files around (though, again, if one is using small- 
sized files like MP3s/AACs, this may not be an issue in practice).

>> Then the only advantage is
>> really more compact size? No big deal for me, I only need one
>
> Are you sure? What if you lose it? What if it gets stolen? What if it
> just plain breaks? Do you want to copy all those CD's all over again?
> Either get two, and keep copies of the work in separate places, or put
> together some routine of backing things up over the web to a filestore
> somewhere. Then if your portable drive breaks, you just need to  
> spend a
> day copying from your last backup, rather than months copying all the
> CD's again.

Absolutely!  The price of big ol' hard drives has become sufficiently  
low that it is _well_ worth the price of a second drive to allow a  
complete back-up of all that data.  Ripping CDs is slow and tedious,  
and I have no desire to do it all over again!

People are more or less paranoid about their backup procedures.  For  
myself, I just keep everything as Apple Lossless in iTunes, and then  
copy the whole iTunes library from one 1TB drive to the other every  
week or so in order to capture any recent additions/changes.  I tend  
to keep the second 1TB drive unplugged and tucked away safely when  
it's not being backed-up to.  Sure, this is not a rigorously perfect  
solution, but it is simple and has worked well enough for my purposes  
so far.  At the very least, my music collection is safer than it was  
when I just had a pile of LPs and cassettes. :)

> The unit itself needs to have a bit more electronics than just being
> storage to make that possible. Essentially it needs to be an MP3 plaer
> in and of itself. There are however speakers which connect to and take
> power from a USB socket, but they'll need to connect to a computer  
> or an
> MP3 player with USB sound output.

My desktop computer has a USB audio interface attached to it anyway  
(that's how I run the guitar into GarageBand :)) and so I just run  
stereo audio back out through it, and thence it can go to the audio- 
ins on a regular audio amplifier or just about anything else.   
Alternatively, I stream over the house's wireless network to an old  
laptop from which a cable runs from the audio out to the home theatre  
thingy.  I have _not_ got an audiophile set up :) but it works well  
enough for parties. :)  Or I can just plug in my headphones and I'm  
good. :)

There are any number of clever solutions for playing digital music  
from computers and iPods and suchlike through various speaker and  
stereo arrangements.  You'll just have to look around for a solution  
that fits your needs (and budget!).

Cheers,
Carl

--
Carl Edlund Anderson
http://www.carlaz.com/