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random observations

Sky-Hi-Fi Snake Oil
Through little fault of my own, I receive the Audio Advisor catalog. Although I spend money on good equipment, I don't do sky-hi-fi. I don't even believe in it, for the same reason I don't gamble at Las Vegas: I can do the math (and physics.)

So this catalog cracks me up. It's filled with crap and snake oil beyond my expectations. And that's what this blog entry is about.

Not everything in this catalog is the other side of shinola. Much of the equipment is top-notch, and the video-tweaking DVDs are very valuable tools for helping calibrate your video system properly. They have a wide variety of radios for multiplexing and for casual listening, and they have nice equipment racks. Even headphone amps make sense given the low-cost circuitry in most equipment, if you have good headphones and use them. But...

What	What's Wrong
AudioQuest NRG-1 Power Cable	This cable for DVD Players "plugs directly into your machine and reduces the signal background noise for a surprising improvement in image clarity and audio fidelity". The internals of the DVD player responsible for fidelity and clarity are not typically AC driven. I'd expect them to be on the far side of a capacitor and conversion to DC. Power cleanliness shouldn't have any impact. But even if it did, without some clever components or a magnetic choke, a cable isn't going to undo the damage of ROMEX in the wall.
PS Audio Power Punch AC Cable $50 Kimber Kable PK110 $280	"Clean up CD Sound or DVD Picture Quality... 12-gauge oxygen-free copper conductors and double shielding to block noise..." Again, you have miles of solid-strand copper ROMEX in your walls prior to this. Unshielded. Shielding that last meter is like trying to revive a drowning victim by holding an umbrella. That horse has left the gate.
Digital Cable Upgrades Monster M1000 Silver ($60 for 1 meter) Cardas Digital Data ($86) Save On Illuminated ($290)	An interesting point about audio: Better cables for analog really can make a significant difference. Analog is susceptible to picking up ambient hum and to losing high frequencies especially. There's no checksum data, no error correction, on analog data. But digital data is designed to avoid those flaws. There's no nuance in the data; either you got it all or you got something that failed the checksum. It's not a case of getting the gist of it - there's no gist, just numbers. But those numbers are easier to get. They don't require as much power or as much bandwidth, both of which are why cell phones moved to digital. For example, suppose you wanted to get a message to a friend on a hill a block away. You could set up a little code (e.g. Morse Code for flashing lights, and successfully converse from miles away. But if you simply held up a sign, even a very large sign, your friend wouldn't be able to read it because the shape of the letters is relevant. Analog vs Digital is like that. Analog is shape and size and spacing-relevant. Digital is just on-or-off. Yeah, there's a lot of them, but computers are very fast. And remember, they're easy to get. So the point is, it's just a "1". There's no difference between a "1" and a 1. None. Better digital cables won't make any difference unless your sound (or image) are occasionally degrading completely. It's a sham upsell.
LightSpeed Optical Signals ($40) MLS1000 Ultra-Low Jitter Optical ($100)	I just covered digital in general in the previous section. But at least it was copper; there are some applications where really good cables are relevant in the copper world, primarily analog signal. But now we're in the optical domain. Here are some quotes from the blurbs for these: "provides low dispersion and highest fidelity"; "most accurate data transfer" "ultra-low jitter" Fascinating. Let's start with dispersion - this is fibre-optic; there's no dispersion. That's why they use it. And fidelity? It's digital, remember? Fidelity is a non-issue. Fidelity means "accuracy", and by definition, if we're getting it at all, we're getting all of it. Sure, a broken cable might cause sporadic bursts of sound, but it won't be low-fidelity. It will be bursts of high-fidelity followed by nothing at all! What about jitter? Jitter is essentially uneven timing of the audio (or video), which in the digital domain is generally from staggered arrival of the packets. Note that it is not from packet loss; packet loss causes drop-outs, not jitter. But staggered arrival is only relevant on networks - phone systems, the internet, etc. - because it can only happen if the packets get held up (e.g. at a router) or lost-and-retransmitted. Home audio equipment lacks any packet acknowledgement process and never resends. It just sends out the packets. If they're missed, they're gone.

So what isn't crap? </td>

Power Conditioners	They don't just filter out "noise". They also smooth out the power, which can be very important for the video quality on the television. They also protect components from brown-out conditions when the video is high-energy (e.g. a white explosion on a plasma) and the subwoofer is simultaneously drawing amps (the sound of the explosion), although for short bursts the equipment capacitors should be sufficient.
Headphone Amps	The built-in headphone amps in most equipment are crap. Cheap ICs that do the job. If you have regular headphones and don't use them a lot, this is fine, but for very high-end headsets, a good amp is probably a good investment.
Tweaking Discs	Most home televisions are very poorly adjusted. Spend half-an-hour (yes, it takes at least that long) with a disc and get it set-up properly. It makes a big difference. I have DVD Essentials for that, but it may no longer be the best; mine is quite old.
Isolation Feet	The need for these may be oversold, but if your disc player (DVD/CD/LaserDisc) is near your subwoofer, or if you have tactile transducers, isolating the disc player is a "good thing", primarily because it keeps the motion steady. But in general bouncing electronics around isn't good for their connections.

Actually, most of the stuff in the catalog isn't crap. But it doesn't take much crap to leave me with a bad taste in my mouth. At least I didn't see any green felt pens in the catalog!