CDs sample 44.1-kHz audio at 16 bits per sample. Considering the standard was defined back in the early 1980s to be played with state-of-the-art technology back then, you’d think this is far inferior to what we could cough up now, right?

Not really. For starters, 44.1 kHz allows the audio to accurately represent any waveforms below about 22 kHz (due to the Nyquist-Shannon theorem). Well, human hearing only extends to about 20 kHz, and less so as you get older. Basically, 44.1 kHz is plenty for high-def audio. DVDs standardized their audio sampling rates at 48 kHz, probably so they have nicer, rounder numbers to work with.

So, do these mega-high-fi 192 kHz do you any good? Nope. Not really at all. Due to the logarithmic nature of human hearing, going that high really does very little for your listening experience.

Don’t believe me? Well, see how well you can hear by trying out the so-called mosquito ringtones. These ringtones are made for teens so that adults can’t hear their phone ring.

So, what about 16-bit? Surely 16-bit means terrible, right? Well, not really. I mean, how bad do your CDs really sound? Granted that 16 bits are quite enough to represent the gamut of sounds that humans can differentiate (16 bits give you about 65,536 levels of sound to play with). Newer systems support 24- and 32-bit audio samples, which should definitely top out humans ability to hear on both ends.

But really, 16 bits are plenty for most people. For one thing, the quietest sound you can possibly hear is about 0.00002 Pascals and the loudest sound you probably ever want to hear (a jack hammer) is about 2.0 Pascals, giving you approximately 100,000 different sound levels between them. 65,536 levels can still put you to the point of hearing loss while allowing you to hear sounds an order of magnitude quieter than the softest whisper.

So, really, 16-bit, 44.1 kHz audio really is pretty decent. Anyone who tells you that you need 192 kHz 64-bit sampling is pulling your leg.

Post from: EveryJoe

Do we care about “high-def” audio?

Well, first off, the HD does not stand for “high definition” (it seems to stand for nothing — it’s just a marketing ploy), and it doesn’t provide anything like HD quality. The second most important part is that you have to have a special receiver to get these, which are still a tad expensive and aren’t standard equipment on much of anything yet.

What does it give you? It gives you the potential for a 300 kbps audio stream. In reality you get little more than 100 kbps of total capacity, which is often split up into multiple channels.

So, there are some goods here: we can cram two or three FM-quality broadcasts in some of the extra bandwidth around current FM transmissions. There is also pressure for these stations to remain commercial-free for a bit longer to increase adoptions, but it won’t last: the service is intended to be free, like current AM/FM stations, so it will have to be ad-supported in the future.

There are a lot of “buts” though:

• It’s proprietary. The only way to make or receive the transmissions on equipment is to pay a royalty to the company that owns the technology, iBiquity.
• It has all of the faults of terrestrial radio. The same problems you have with AM and FM stations will stay with these HD Radio stations. HD Radio is supposed to be some sort of response to satellite radio providers, but is still limited to your local area and whatever music they decide to put on.
• There have been some complaints that the HD Radio signals are incredibly weak, faint, and interfere with other signals because of the way they are transmitted.
• Quality isn’t much better than satellite. I was an XM subscriber for a while, and their audio bitrates were typically 40 kbps for the popular music channels, and less (8–24 for stations like news, etc.). Although HD Radio has the potential to exceed this, the providers are more likely to just populate the bandwidth with more channels, giving about the same quality as satellite providers.
• No one knows about them! If no one figures out or cares enough about them, then they will just die.

Personally, unless iBiquity can get HD Radios into every new car that comes out, I don’t see it as being a lasting business: DOA. Satellite is better in almost every way, and is already an installable option in many vehicles nowadays.

And it certainly isn’t HD.

Post from: EveryJoe

Who put the “HD” in “HD Radio”?

Even some artists online are selling FLACs of their music for the high-def audiophiles out there. For example, Jonathan Coulton has a FLAC store.

A problem I have is that once I’ve bought said music and want to listen to it, or if I want to listen to my old FLAC files, I am stuck on my computer. What about my iPod?

Well, there are several options, most of which are bad. Most involve hacks, like using the standard FLAC utilities (for example, installed from Fink) to convert it to a WAV and then import it into iTunes. However, with these kinds of methods, you often lose all of your metadata (artist, album, title, etc.), or you have to resort to some fancy shell scripting to convert them.

This is where XLD (X Lossless Decoder) comes in. It supports converting to and from a variety of formats, including FLAC, Apple Lossless, AAC, WAV, MP3, Vorbis, and WavPack. The best feature is that correctly converts the metadata from one format to the other. It’s also dead simple to use: simply set your preferences to what you want, i.e., for Apple Lossless:

Then open the file you wish to convert from whatever (e.g., FLAC) and it pops out as Apple Lossless in just a few seconds. The size difference between the two formats in the test file I just checked was about 1.1% (with Apple Lossless being smaller than FLAC).

Post from: EveryJoe

FLAC to Apple Lossless on OS X: XLD

Well, it’s a compression standard dating back to 1991 that shrinks the size of audio by throwing away parts we don’t hear very well. The higher the compression ratio, the more information is thrown away and the lesser the quality of sound.

Needless to say, we’ve learned a lot about audio compression in the years since 1991. After all, MP3 is part of the first set of standards on digital video set forth by MPEG (MP3 = MPEG 1, Layer 3). There are a lot of modern alternatives that are worth considering for your audio collection.

What would you move to? Well, there are a few options. We’ll start with the most direct competitor to MP3:

AAC is the most popular: it’s has been made widely popular as the audio codec of choice of iTunes and iPod. In addition, support is strong among hardware and software players, as almost every major vendor supports it. And with good reason: it’s a very decent codec, engineered more recently than MP3, and sounds better than MP3 at the same bitrate. The only two downsides to AAC are that iTunes, by default, encrypts the AACs you buy from them (this is changing soon, and does not affect ones you rip yourself).

Another strong competitor to the powerhouses that are AAC and MP3 is Ogg Vorbis (often just referred to as “Ogg”, despite the fact that there are several other Ogg codecs). Ogg’s appears to be of similar quality to AAC, and is completely free. Support is mixed: many software players support natively or through add-ons, but hardware support is very lacking. For some reason or another, it just never really caught on.

MP3, AAC, and Ogg are all lossy codecs, as opposed to lossless. The difference being that lossless audio codecs have the exact same quality as the original source, whereas lossy codecs make no such guarantees. But the lossless codecs also require much more storage space. (But, with ballooning hard drive sizes, are we really concerned with how much space our songs take nowadays? This used to be critical when I had a 4 GB hard drive, but in the 1+ TB age … not so much.)

Compare the normal, lossy codecs like MP3 and AAC: these have typical bitrates of 128–256 kbps, meaning that a 3-minute song is roughly 3 to 6 MB in size. With no compression, the same song would be about 31 MB in size. The lossy codec would preserve most of the quality, but there is loss of information. The lower the bitrate encoded, the more “tinny” it will sound. Most people can’t tell, so lossy codecs are very popular due to their small size.

For audiophiles, though, any loss is too much. This is where lossless codecs come in, giving sizes of around 15 MB for a 3-minute song. The main competitors are probably FLAC and Apple Lossless.

FLAC is the Free Lossless Audio Codec. It has good compression ratios and is well supported in software. As a matter of fact, I used it for quite a while since it is the only format that was (at the time) well-supported by Windows, OS X, and Linux. Hardware support is fairly poor, with almost no hardware vendors supporting it. Honestly, this is sort of to be expected with lossless codecs in general. Except …

Apple Lossless is Apple’s proprietary lossless codec. However, it’s not too proprietary, as it has been successfully reverse engineered and supported in many major music players recently, including VLC. Hardware support is “limited” to Apple iPods (other than the Shuffle), as far as I know. Limited in the sense that it supports only the most popular portable music player in the world. It’s fairly comparable in abilities to other lossless codecs, typically giving you an audio file about half the size of a raw WAV file.

So, after all of this, what is the verdict? MP3 is dead. It’s only good component is that it is universally supported. But AAC is extremely well supported, more modern, and sounds much better. For true audiophile needs, sticking with FLAC or Apple Lossless is your best option.

Personally? I rip all of my albums from CDs using both AAC (typically 192 kbps) and Apple Lossless. This way, if I ever get pickier in the future about my audio, I can just re-encode it later, but in the mean time I can fit plenty of songs on my iPod.

Post from: EveryJoe

It’s time to ditch MP3

In the past, I’ve been of the opinion that your audio equipment should be completely separate from your video equipment: the additional splitters used in the all-in-one home theater systems could cause noise and signal delay problems. In addition, you’d be stuck with a monolithic solution that would eventually stop being up-to-date when either the audio or video components became outdated. They should be separate and connected via S/PDIF, I always said.

For the most part, this was true, especially with DVDs. And if you bought an S-Video or component home theater kit, you’d be pretty out of luck with HDMI.

But, when Blu-ray comes along, it has a theoretical audio bitrate of 28 Mbps of raw audio, or up to nearly 19 and 25 Mbps for Dolby TrueHD Lossless and DTS HD, respectively.

The problem? Your S/PDIF line (either using an optical Toslink or coaxial RCA cable) only supports up to 3 Mbps, or so, and possibly less. The audio receivers that only support S/PDIF and analog inputs don’t stand a chance to understand the highest quality streams.

So, how does that audio get from your Blu-ray disc to the audio system? HDMI. This is also the video transport cable, so your home audio solution must be integrated with whatever video you are running as well. The days of separate audio and video receivers is over.

Thus, with a sad heart, I must buy a monolithic, all-in-one home theater package.

Post from: EveryJoe

Digital audio buying tips

EngadgetHD all day has posted a bunch of galleries of their experiences at CEDIA, the trade show for companies to show off their new HD gadgets off to the world. To say the least, they really spent a lot of time touring and taking pics of all the new shiny TVs, DVRs, and other HD components that could be found on the showroom floor. Here is a round-up of all the links to their tours going from the first to most recent:

• FUZE Media System
• Sony
• LG
• Sharp
• Toshiba
• Philips
• JVC
• Mitsubishi
• Hitachi
• Epson
• Fujitsu
• Panasonic

Hold on, need a breath… And here we go…

• Moxi
• Sanyo
• Dish Network
• DirecTV
• Logitech
• Samsung
• Yamaha
• Gefen
• Monster Cables
• Denon
• Klipsch
• Alienware
• And finally, HD-DVD

Phew… Glad that’s over. Although chances are there may be more to come. Stay tuned for more shiny fun!

Post from: EveryJoe

Roundup of CEDIA Tours (So Far)

HD Radio has been mainly advertised for your cars and other automobiles, except for the occasional RadioShack ad on the radio, but Sony is looking to change that around a little bit. EngadgetHD released a quick, and I mean quick, run down of what they like and don’t like.

We like:

• Gorgeous, mid-century modern design.
• Clear, easy to read display, even uses RDS.
• Phone-like reception meter even works with AM/FM.
• Decent enough sound output.

We don’t:

• Massive friggin power brick. Oh, and it can’t be unplugged from the unit.
• Annoying to scan channels with the dial.
• Included aux cable looks like it will fit your iPhone. But it doesn’t.
• Actually still blinks 12:00 if you don’t set it. Sheesh.

They also have a photo gallery on their site for shots from all angles. Click the link below for the main article.

Via [EngadgetHD]

Post from: EveryJoe

Sony XDR-S3HD Run Down on EngadgetHD