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New Digital Audio Formats
Hack Jandy writes "Anandtech is running an article about new digital audio formats, including DVD-A and SACD. It also discusses how the newest digital audio processors from Intel will handle these audio formats in the future; a good primer for anyone interested in something a little more capable than CDs."
You want 5.1 (or more) channel sound in your compressed audio? Ogg Vorbis has it today. mp3's founders are working hard to hack something into that format, but that's all it is, a hack.
This was a really, really uninformative article. Bonus points for being "blurbed" as about DVD-A/SACD and then having almost nothing about them.
I have a DVD-A/SACD player. It's hooked up to a home theater system that toals out at about $6,000, not counting TV. DVD-As and SACD do definitely sound better than CD, but they only sound better in scenarios where a person has a stereo that runs more than about $1,000. Below that point, the limiting factor isn't their media but the speakers.
That said, I really regret having purchased it. I'm not a huge classical music fan, and my interest in jazz is minor. There aren't a huge amount of major releases out there for someone like myself. It is amusing, though, to go to the store and see the completely random stuff that does make it out (The Bangles Greatest Hits? Queensryche?!? The Top Gun Soundtrack?).
i remember reading about SACD in 1999.
i'm trying to give up sigs.
Hmm, thought i'd read this before.
3 7873
http://slashdot.org/comments.pl?sid=106150&cid=90
...and you need to read up on the anatomy of the ear.
The most dangerous technology is that which is "just good enough". CDs have filled a void perfectly and the average person is perfectly happy with the marginally inferior audio quality they provide as opposed to LPs.
This whole better-sound-from-lps is a bit of a strange myth. Maybe, on a first listening, *if* and only if you keep all of your audio equipment in a clean-room, you might better sound quality.
Since most people don't have the luxury of a clean room and a pristine LP for each listening, better sound quality is hard to get. If it exists at all.
I spent a while recording some LPs to CD a while back on some dedcent equipment (not pro or anything, but not junk). LPs are incredibly static prone. If you so much as look at them they get all charged up and attract most of the dust in the room. Once you manage to get most of the dust out of the tracks (it's impossible to get it all out, and any left degrades the sound quality) you will notice that the sound quality of any of your favourite LPs (ie the ones you listen to lots) will be degraded because they wear. Oh, and of course, you have to go through the hassle of getting all the dust removed *every**time* you want to listen (or you get very crackly sound).
With a CD, as long as you take a bit of care not to scratch the hell out of it, you put it in and get pretty much error free sound every time. With out all the crackling.
SJW n. One who posts facts.
You have your terminology totally wrong, first off. You state that noone needs a frequency range greater than 40kHz; what you meant to state was that noone needs a *sampling rate* greater than 40kHz. The 20kHz you state next is the frequency range of human hearing (usually a little bit lower for adults, most adults will top out in the 15-19kHz range).
Engineers need to work at high bitdepth and sampling rate, not at high frequency range, although FR is a direct consequence of sampling rate.
Next; there's no such thing as a floating point sampling rate. You're thinking bitdepth, and using a floating point bitdepth is uncommon. Most current digital editing systems (i.e. ProTools) record 24bit fixed point audio during tracking, and maintain some higher level of precision during mix; IIRC, ProTools 5 had 60 bit main buses, but I could be quite off on that.
Next, physics.
Yes, theoretically you only need 2xBW (bandwidth), but anyone who actually works on this shit will tell you that they want more. This is because in order to avoid aliasing artifacts, you need to filter everything above BW. Unfortunately, brick wall filters are not implementable in realtime (and not really implementable in a stored data system either, but that's another story again). So you've got a non brick wall filter, which means you need some frequency range above your max desired signal frequency, but below your 1/2Fs frequency. This range is where your filter is transitioning from passband to stopband.
Next, we have beating artifacts. This occurs when you have a sound at a frequency very close to your 1/2Fs frequency; while frequency will be properly reproduced, you'll get amplitude modulation artifacts. Because of beating, typical industrial sampled data systems sample at a minimum of 5xBW; 10 or 20x BW is preferred. Since we're looking at a 20kHz BW, 192kHz (DVD-A) should do quite nicely.
I'm with you on the lack of dynamic range in modern music though; load a Britney Spears track into an editor, then load a classic jazz track (I recommend Miles Davis' "So What") and compare the envelopes. Scary.
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Mod me down, you fucking twits. Go ahead. I dare you.
(I read with sigs off.)
A rather cheap one, sadly, but the sound is still incredibly good. Dylan's Blonde on Blonde sounds fantastic in 5.1, and the choir in the Stones' You Can't Always Get What You Want has never sounded better. Dark Side of the Moon is, of course, astounding. In all cases, higher frequencies sound better than they do on standard CDs.
As far as pricing, I bought most of the SACDs new for about $10-11/disc.
AAC is *not* lossless. It is much better than mp3 just as good as ogg. But not lossless.
Cypherpunks: Civil Liberty Through Complex Mathematics. Those who live by the sword die by the arrow.
They've been around since at least 1999 - see here.
I've never used AAC or OGG.
Both FLAC and Apple's .m4a are essentially lossless. In any case, they sound far better to me than mp3. Big lunking files, though.
This is my post. There are many others like it. If you don't like what you read here, go try one of the others.
Why do people assume that the people who designed CDDA were stupid? No amplifier/speaker/room combination at any price is accurate enough to resolve the resolution of CD audio. The air current around your ears is louder than the CD noise floor, and the human ear is not equipped to hear a 20khz tone.
I mostly agree with you, but I feel the need to point out that your "air current" description is way off. As someone who often likes his music LOUD, I feel compelled to point out the the usable dynamic range of the human ear is MUCH more that the ninety-something dB provided by CDs.
An expensive, high-powered stereo can hit 120-130 dB. This leaves you with 30dB of noise.
24-bit audio give you more like 140 dB of dynamic range, which allows your playback system to have a range much more in line with the actual capabilities of the human ear.
96KHz, on the other hand, only really makes sense on the RECORDING side of things, where and analog filter must be used that will block all frequencies above the sampling rate.
Also, it's worth pointing out that doing any sort of DSP on an audio signal in going to make you want even more bits of A/D so that the "rounding errors" that result stay down in the noise.
Life is too short to proofread.
most SACDs have a regular cd audio layer
Many titles do not have a Red Book layer.
besides, WHAT POINT IS SURROUND SOUND IN HEADPHONES?
It's for those SACD titles that come with neither a Red Book layer nor a stereo mix. Apply a variant of the earwax algorithm that Sox uses to move the perceived sound stage of stereo recordings in front of the listener, and surround encoded recordings will still sound OK.
One thing: FORGET IT.
You WONT get 120db out of any high powered home stereo. 130 NO CHANCE IN HELL.
Any box of acceptable quality (so no boom-horns that make your rave loud but have 20%jitter) will yield between 85 and 90, perhaps 95db/m*W (95 is a real upperlimit, only reachable by transmissionline boxes or other stuff). So make your math: If you are 2m from your speakers, you need 5kW sinus output of your amp to listen to your "quality"-musik.
And i BUT you DONT.
So STFU
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Article
Early CDs had problems with the foil peeling off. I still have problems with brand new CDs destroying themselves (I have ~270 discs and have had to repurchase five with two more that I recently noticed had pits in the foil...). I think it's the printing; I rip my CDs, put the cases on a rack, and then the disc in a binder that is stored away in a cool dry place. I've had the most problems with CDs from Century Media; they recently changed their printing methods and the newer discs don't seem to have any problems (so far).
That said, I still have the first CD I ever got when I was ten (1996) and it's been through a lot of abuse and still plays fine.
HAL 7000, fewer features than the HAL 9000, but just as homicidal!
Erm, but there are, what, 3 bitrates for ATRAC3 so you can have anything from CD quality to half of the bitrate of a 128kbit MP3. And the 66kbit (??) ATRAC3 is better than a 128kbit MP3... maybe not as good at a 192kbit MP3 but you can get 80mins of CD-quality ATRAC audio on a MD and the medium-quality ATRAC will fit 160mins of pretty darn decent audio on one MD, otherwise 320mins of fairly accurate audio on one MD.
Even worse than MP3? Do you use 320kbit MP3s or something?
FYI, the mp4 format is sorta a container format, similar to quicktime. The AAC audio and Apple Lossless audio both use the m4a extension, and the protected versions use m4p.
You're confusing conversion and calculation. ProTools is a multitrack program; the idea behind allowing that much bitdepth on the main buses is to provide a ton of headroom for mix and processing. 60 bits is probably overkill, but I know they use at least 48 bits on the main bus (remember, the program may have 256 tracks, each with a 6dB boost, leading to a 9 bit increase over single track - beyond that, plugins and such may lead to even higher gains, which is why they provide so much headroom).
D/A converters can't physically have an effective range better than 20 bits at room temperature (without getting into more exotic architectures like sigma-delta converters), but that doesn't mean that processing shouldn't work on higher bit-depth bussing.
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Mod me down, you fucking twits. Go ahead. I dare you.
(I read with sigs off.)