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Compressed Audio Thread (Codecs, not bad mastering)

Posted: Sat Sep 11, 2004 3:15 am
by Kjoerup
Unless I somehow missed it, it appears that there hasn't yet been a thread here which discusses compressed audio technology -- the good, the bad, and the ugly. We've thoroughly (un)covered the "hi-rez" scam, so I'm wondering what everyone thinks about the other end of the spectrum: mp3, AAC, Ogg, general musings and philosophy, etc., etc.

I lurk occasionally at Hydrogen Audio. (HA, where, in sharp contrast to some "other" forums, science dominates the discussions -- and is expected to; unsubstantiated claims like "Mp3 sux! El Pees are a million times better!" are roundly and rightly dismissed. Well, you can say that there, but you better have some scientific proof to back up your claim.)

So, to begin the discussion ... I've participated in several formal ABX listening tests, both in the US and Germany. I've yet to be able to identify any difference between an original WAV source and a properly encoded, high bitrate mp3 or AAC file. I know there are some people that claim that they can, though I've yet to personally witness it.

The lesson being, I suppose, is that modern codecs -- properly handled, of course -- are indeed more than adequate for everyday listening.

Posted: Sat Sep 11, 2004 9:45 am
by Rspaight
I haven't done a ton of comparing in this area, but I did recently check out a 192K MP3 (served from an iPod) compared to the original CD (on a Cary tube amp, even!). The MP3 sounded darn good, with maybe some fuzziness on the high end. Of course, this wasn't ABX, and the iPod's electronics were a big variable, so your mileage may vary. But both of us doing the listening were surprised how well the MP3 held up under close scrutiny.

256K MP3s sound great to me -- I can't tell the difference. 128K MP3s, on the other hand, definitely exhibit noticeable compression artifacts.

Ryan

Posted: Sat Sep 11, 2004 11:33 am
by Dob
Rspaight wrote:The MP3 sounded darn good, with maybe some fuzziness on the high end.

That's what I'm hearing...the best MP3s that I've heard reproduce all the frequencies very well with the exception of the extreme top end, which sounds a bit "smeared" or distorted. I confess that I don't know if those were at the very highest bitrate, though.

Posted: Sat Sep 11, 2004 12:56 pm
by Xenu
I recognize that, at higher bitrates, MP3s essentially sound indistinguishable from the original recordings in most of the "important" ways. That said, I still won't make CDs from MP3 sources. Why? I'm unsure. I think it's something of a personal prejudice; though I recognize that I can't usually tell the difference between an alt-preset-extreme version of a song and the original WAV file, I prefer to keep my listening sources as "pure" as possible. Besides, with storage so cheap nowadays, it's really not much of a jump from high-bitrate-MP3 to lossless.

Posted: Sat Sep 11, 2004 5:09 pm
by Rspaight
Dob wrote:
Rspaight wrote:The MP3 sounded darn good, with maybe some fuzziness on the high end.

That's what I'm hearing...the best MP3s that I've heard reproduce all the frequencies very well with the exception of the extreme top end, which sounds a bit "smeared" or distorted. I confess that I don't know if those were at the very highest bitrate, though.


Which makes sense, since one thing an MP3 does is aggressively filter the highest-end stuff on the assumption that most adult humans can't hear it anyway. Depending on how good the filters are, that could have a noticeable effect on adjacent frequencies that *are* audible.

Ryan

Posted: Thu Sep 16, 2004 10:56 am
by krabapple
I've recently transferred all my rock and jazz CDs (about 800) to a pint-sized 300 Gb hard drive (the Maxtor One-Touch, which cost less than $1/gig) . When I began I was converting them all to variable bitrate mp3s encoded as per hydrogenaudio.org's recommendations -- and which I have found to be indistinguishable from originals -- but partway through, changed my mind and decided to go with FLAC, a lossless compression format. The reason: once you've compressed to mp3, you can't recover the original file, and transcoding to other formats is generally a sonic no-no; with FLAC and other lossless formats, that's not an issue. I can store all my file in a form more compact than native .wav (about 40%-50% reduction on average) *and* have them all available for quick decoding to .wav and compression to mp3 , if I want to go portable.

Basically, in my view, FLAC is for serious compressed archiving, mp3 isn't. And there's no 'audiophile paranoia' issue (the irrational feeling that there *must* be some audible degradation, even though you can't hear it).

Posted: Thu Sep 16, 2004 11:45 am
by Patrick M
Lukpac doesn't like FLAC.

Posted: Thu Sep 16, 2004 3:40 pm
by krabapple
Patrick M wrote:Lukpac doesn't like FLAC.


That's wack. Are you talking smack?

Posted: Thu Sep 16, 2004 3:54 pm
by Patrick M
No, in fact.

Posted: Thu Sep 16, 2004 4:32 pm
by Xenu
Buy socks, not rocks.

Posted: Thu Sep 16, 2004 5:13 pm
by Rspaight
FLAC is a hack,
It's hard on a Mac,
To compress a track
From CD, vinyl or shellac.

Ryan

Posted: Fri Sep 17, 2004 5:20 pm
by krabapple
If your baseline is Mac
when test-driving FLAC
you must be on crack

FLAC on PC:
it's the bee's knees

Yoko broke up the Beatles.

Posted: Sun Oct 03, 2004 11:06 pm
by Kjoerup
I've recently transferred all my rock and jazz CDs (about 800) to a pint-sized 300 Gb hard drive (the Maxtor One-Touch, which cost less than $1/gig)


Krabapple, I'm also in the ongoing process of converting nearly 1000 CDs to lossless. I've had my eye on that Maxtor One-Touch (it's pretty cheap at Costco). Could you tell me if it's quiet? That's my main concern - how loud is the damn thing going to be? Most forums where I've asked this question point me to outrageously expensive external firewire drives. No way am I going to pay $500 plus for a hard drive (unless it's at least 600 GB). The Maxtor looks pretty good to me, provided that it isn't a noisy beast. Please let me know what your assessment of it is. Thanks.

FLAC is a hack,
It's hard on a Mac,
To compress a track
From CD, vinyl or shellac.


I tried FLAC on Mac. Too problematic. Slow encode, iTunes won't play it, and so on. Apple Lossless is a godsend. (Though I rip the aiffs with cdda2wav, not iTunes.) Fast, simple, easy tagging. Works equally well on iTunes for Windows too.

Posted: Mon Oct 04, 2004 11:20 am
by krabapple
The One-Touch is very quiet. I heard some buzzing noise from mine once, and it turned out it had wiggled loose from its 'stand' a tiny bit. I pressed it back in and it was quiet again. The Dell PC it's normally USB'd to is by *far* the noisier component.

I'm totally happy with the Maxtor so far -- setup was a breeze and it's been simplicity itself to use. I just hope it doesn't prove to be something that tends to 'die young'.

Too bad about FLAC and Macs. I use foobar2K as the playback-ware, and that's PC-only too, alas. Slow encodes don't bug me much -- I'm almost always encoding while ripping with EAC, and the ripping is the rate-limiting step 99.9% of the time. Apple seems to be doing a great job with their offerings in all these areas, though.

Posted: Mon Oct 04, 2004 1:26 pm
by Patrick M
YMMV, but I *really* don't like Maxtor drives. Too noisy and too prone to failure. I'd get a WD or Seagate, personally.